Hybrid algorithm CTO-PCI in a Resource-Constrained Tunisian Center

Hybrid algorithm CTO-PCI in a Resource-Constrained Tunisian Center | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Hybrid algorithm CTO-PCI in a Resource-Constrained Tunisian Center Mohamed Aymen Ben Abdessalem, Jaouaher Benhafsa, Zied Ben Ameur, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9113443/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 16 You are reading this latest preprint version Abstract Background: Evidence on chronic total occlusion percutaneous coronary intervention (CTO-PCI) from North Africa remains scarce, with limited data on procedural outcomes and patient-centred endpoints in resource-constrained settings. Methods: Prospective single-centre study of 114 patients undergoing 134 CTO-PCI procedures (2022-2024) at Farhat Hached University Hospital, Tunisia. CTOs were treated using contemporary hybrid algorithms. Technical success required TIMI 3 flow with <30% residual stenosis. Primary endpoint: immediate outcomes and technical success predictors. Secondary endpoints: 12-month major adverse cardiac/cerebrovascular events (MACCE), target lesion failure (TLF), and symptom improvement (CCS/NYHA class). Multivariable logistic regression identified technical failure predictors. Results: Mean age was 60.9±9.1 years; 84.2% male. High-risk features included diabetes (60.5%), smoking (72.8%), and severe LVEF≤35% (20.2%). Median J-CTO score was 2 (IQR 1-3). Technical success was 82.1%, improving from 66.7% (2022) to 88.8% (2024; p=0.011). Independent technical failure predictors were J-CTO≥3 (OR 4.07, 95%CI 1.53-10.88) and LVEF≤35% (OR 3.90, 95%CI 1.38-11.04). In-hospital MACCE was 2.6%; periprocedural complications 14.2% (major: 4.5%). At 12 months, MACCE was 13.2% (86.3% MACCE-free survival); TLF 2.6%. Successful CTO-PCI predicted lower MACCE (8.7% vs 60%, p<0.001) and superior symptomatic improvement at 12 months, with marked reductions in CCS and NYHA class compared with technical failure (p=0.013 and p=0.011, respectively). Conclusions: Structured hybrid CTO-PCI in a North African centre achieved registry-comparable technical success (82.1%) and safety despite higher-risk patients and resource limits. Success strongly associated with mid-term event reduction and substantial symptom improvement, supporting scalability of modern CTO programs in emerging economies. Chronic Total Occlusion Percutaneous Coronary Intervention Angina Prognosis Figures Figure 1 Figure 2 Introduction Chronic total occlusion (CTO), defined as a complete coronary artery obstruction with TIMI 0 flow of presumed duration ≥ 3 months, represents one of the most complex subsets of coronary artery disease. CTOs are identified in approximately 15–20% of patients undergoing coronary angiography and are particularly prevalent among individuals with ischemic cardiomyopathy and reduced left ventricular ejection fraction [ 1 – 3 ]. Percutaneous coronary intervention for CTO (CTO-PCI) remains technically demanding and has historically been associated with lower procedural success rates and increased complication risk compared with non-occlusive lesions [ 4 ]. Over the past decade, however, advances in dedicated devices, refinement of antegrade and retrograde techniques, and structured hybrid approach implementation have markedly improved success rates in experienced centres [ 5 ]. Although composite event-based outcomes such as major adverse cardiac and cerebrovascular events (MACCE) are commonly reported, symptom relief and functional improvement remain the primary clinical drivers for CTO revascularisation [ 6 ]. Contemporary guidelines therefore recommend CTO-PCI mainly in patients with persistent angina despite optimal medical therapy and objective evidence of ischemia or viability in the CTO-related territory [ 7 ]. Despite these advances, most available data originate from North American, European, or East Asian registries. Evidence from North Africa is extremely limited, and prospective evaluations of procedural and technical success, safety, and patient-centred outcomes in Tunisian populations are scarce. Differences in demographic characteristics, comorbidity burden, healthcare resources, and interventional practice patterns may influence outcomes and limit the generalisability of international data to this region [ 8 ]. Farhat Hached University Hospital in Sousse has developed a dedicated CTO program with progressive adoption of contemporary revascularisation strategies. Evaluating outcomes from this centre provides an opportunity to generate locally relevant data and to benchmark Tunisian results against established international registries. To address this regional evidence gap, we conducted a prospective observational study between January 2022 and December 2024 to evaluate real-world outcomes of CTO-PCI in a Tunisian cohort. The primary objective was to assess immediate procedural outcomes and determinants of technical success. The secondary objective was to evaluate twelve-month clinical and functional outcomes, including MACCE, target lesion failure, and changes in angina severity. Methods We prospectively analysed 114 patients who underwent 134 CTO-PCI procedures between 1 January 2022 and 31 December 2024 at the Cardiology Department of Farhat Hached University Hospital, Sousse, Tunisia. Data were collected in real time using standardised case report forms and cross-verified against medical and catheterisation laboratory records. CTO was defined according to CTO-ARC criteria as angiographic TIMI 0 antegrade flow with an estimated duration ≥ 3 months. Indications for CTO-PCI were consistent with contemporary ESC and Euro-CTO recommendations and were confirmed following multidisciplinary evaluation [ 7 ]. Patients were eligible if aged 18–85 years with angiographically confirmed CTO and guideline-based indications, including persistent angina despite optimal medical therapy, objective ischaemia (≥ 10% of left ventricular myocardium), or evidence of viable myocardium in the CTO territory [ 1 , 7 ]. Selected ST-segment elevation myocardial infarction patients with concomitant non-infarct-related artery CTO undergoing complete revascularisation were also included [ 1 ]. Written informed consent was obtained from all participants. Exclusion criteria comprised non-viable myocardium, cardiogenic shock, contraindication to dual antiplatelet therapy or iodinated contrast, and inability to complete follow-up. Baseline variables included demographics, cardiovascular risk factors, prior cardiac events, renal function, and clinical presentation. Symptom severity was assessed using the Canadian Cardiovascular Society (CCS) angina classification and the New York Heart Association (NYHA) functional class [ 9 , 10 ]. Left ventricular ejection fraction was measured using Simpson’s method and categorised as preserved (≥ 50%), moderately reduced (35–50%), or severely reduced (≤ 35%). Coronary angiograms were independently reviewed by two experienced operators. Recorded variables included target vessel, lesion morphology, calcification, collateral grade (Werner classification), and lesion complexity assessed using the J-CTO score (< 3 vs ≥ 3) [ 11 , 12 ]. CTO-PCI was performed using a contemporary hybrid strategy allowing transition between antegrade and retrograde techniques. Access site, crossing strategy, devices used, procedure duration, fluoroscopy time, and contrast volume were documented. Technical success was defined as restoration of TIMI 3 antegrade flow with < 30% residual stenosis [ 1 ]. Procedural success was defined as technical success without in-hospital major adverse cardiac and cerebrovascular events (MACCE) [ 1 ]. In-hospital MACCE, assessed at patient level, included death, stroke, myocardial infarction, or urgent repeat revascularisation. Major procedural complications, assessed at procedure level, included peri-procedural death, stroke, myocardial infarction, collateral perforation with tamponade, acute stent thrombosis, donor vessel dissection, and major vascular complications. Patients were systematically followed for twelve months. The primary endpoint was immediate technical and procedural success and its determinants. Secondary endpoints included twelve-month MACCE, target lesion failure, and change in CCS and NYHA class, with clinical improvement defined as a reduction of at least one class. Statistical analyses were performed using IBM SPSS Statistics version 25.0. Normality was assessed using the Shapiro–Wilk test. Continuous variables were compared using Student’s t-test for normally distributed data or the Mann–Whitney U test for non-normal distributions. Categorical variables were analysed using the χ² test or Fisher’s exact test as appropriate. Paired pre- and post-procedural comparisons of CCS and NYHA class were performed using the Wilcoxon signed-rank test. Kaplan–Meier analysis was used to estimate MACCE-free and target lesion failure-free survival, with comparisons performed using the log-rank test. Patients were censored at the time of last follow-up or event occurrence. Variables with p < 0.20 in univariate analysis that were considered clinically relevant were entered into a multivariable logistic regression model to identify independent predictors of technical success. Results are reported as odds ratios with 95% confidence intervals. All statistical tests were two-sided, and a p-value < 0.05 was considered statistically significant. Results During the study period, 114 patients underwent 134 CTO-PCI procedures involving 121 CTO lesions. Overall catheterisation laboratory activity increased substantially, with CTO-PCI procedures rising from 18 in 2022 to 80 in 2024, representing approximately 7% of all PCI procedures in the final year. Baseline clinical characteristics are summarised in Table. Stable angina was the predominant presentation (76.3%) with most patients experiencing high symptom burden per Canadian Cardiovascular Society (CCS) grading, predominantly CCS III (59.8%) and CCS IV (18.4%). A small proportion (2.6%) were asymptomatic for angina but presented with dyspnoea. Among clinically stable patients, angina severity was predominantly moderate to severe, with 78.2% classified as CCS class III–IV. Functional limitation was less pronounced, with 21.8% in NYHA class III–IV. Left ventricular systolic function was preserved (LVEF ≥ 50%) in 52.6% of patients, moderately reduced (35–50%) in 27.2%, and severely reduced (≤ 35%) in 20.2%, with a mean LVEF of 43.9 ± 12.9%. Regional wall motion assessment showed hypokinesia in 71.1% of CTO territories, normal motion in 25.6%, and akinesia in 3.3%, with no dyskinesia observed. Angiographic characteristics of the included patients are summarised in Table 2 . Multivessel coronary artery disease (≥ 2 diseased vessels) was identified in 86 patients (75.4%). Table 1 Baseline clinical characteristics of the included patients according to technical success Variable Overall (N = 114) Not successful (n = 10) Successful (n = 104) p value Age (years) 60.9 ± 9.1 64.6 ± 10.1 60.5 ± 9.0 0.17 Male gender 96 (84.2%) 8 (80.0%) 88 (84.6%) 0.70 Current smoker and former smoker 83 (72.8%) 4 (40.0%) 79 (76.0%) 0.002 Diabetes mellitus (NID/ID) 69 (60.5%) 8 (80.0%) 61 (58.7%) 0.19 Hypertension 66 (57.9%) 5 (50.0%) 61 (58.7%) 0.60 Dyslipidaemia 79 (69.3%) 6 (60.0%) 73 (70.2%) 0.51 Obesity 14 (12.3%) 0 (0.0%) 14 (13.5%) 0.22 Peripheral arterial disease 24 (21.1%) 1 (10.0%) 23 (22.1%) 0.37 COPD 5 (4.4%) 0 (0.0%) 5 (4.8%) 1.000 Renal failure on dialysis 2 (1.8%) 0 (0.0%) 2 (1.9%) 0.66 Prior stroke 3 (2.6%) 0 (0.0%) 3 (2.9%) 1.000 Clinical presentation Stable angina 80 (70.2%) 5 (50.0%) 75 (72.1%) 0.31 ACS (UA + MI) 29 (25.4%) 4 (40.0%) 25 (24.0%) Dyspnoea 5 (4.4%) 1 (10.0%) 4 (3.9%) Prior PCI/CABG/MI history Previous myocardial infarction (overall) 72 (63.2%) 7 (70.0%) 65 (62.5%) 0.64 Previous MI in CTO territory 29 (25.4%) 4 (40.0%) 25 (24.0%) 0.27 Previous PCI 68 (59.6%) 6 (60.0%) 62 (59.6%) 0.98 Previous PCI in CTO territory (re-occlusion) 17 (14.9%) 1 (10.0%) 16 (15.4%) 0.65 Previous CABG 6 (5.3%) 1 (10.0%) 5 (4.8%) 0.48 Previous CABG in CTO territory 5 (4.4%) 1 (10.0%) 4 (3.8%) 0.36 Left Ventricular Ejection Fraction (LVEF) ≤ 35% 23 (20.2%) 4 (40.0%) 19 (18.3%) 0.010 > 35% 91 (79.8%) 6 (60.0%) 85 (81.7%) ACS: Acute coronary syndrome. UA: Unstable angina. MI: Myocardial infarction. STEMI: ST-segment elevation myocardial infarction. NSTEMI: Non–ST segment elevation myocardial infarction. COPD: Chronic obstructive pulmonary disease. BMI: Body mass index. CABG: Coronary artery bypass graft surgery. CTO: Chronic total occlusion. PCI: Percutaneous coronary intervention. LVEF: Left ventricular ejection fraction. Table 2 Angiographic characteristics of the included patients according to technical success Variable Category / Value Overall (N = 134) Not successful (n = 24) Successful (n = 110) p value Number of diseased vessels (including CTO) 1 vessel 28 (24.6%) 2 (20.0%) 26 (25.0%) 0.74 2 vessels 42 (36.8%) 3 (30.0%) 26 (25.0%) 3 vessels 44 (38.6%) 5 (50.0%) 39 (37.5%) CTO artery LMT 3 (2.2%) 1 (4.2%) 2 (1.8%) 0.637 LAD 63 (47.01%) 14 (58.3%) 49 (44.5%) LCx 14 (10.44%) 2 (8.3%) 12 (10.9%) RCA 52 (38.8%) 7 (29.2%) 45 (40.9%) SB 2 (1.4%) 0 (0%) 2 (1.8%) CTO location Ostial 15 (11.2%) 4 (16.7%) 11 (1%) 0.710 Proximal 53 (39.6%) 10 (41.7%) 43 (39%) Mid 60 (44.8%) 9 (37.5%) 51 (46.4%) Distal 6 (4.5%) 1 (4.2%) 5 (0.45%) In-stent CTO 16 (11.9%) 1 (4.2%) 15 (13.6%) 0.195 > 1 CTO segment 49 (36.6%) 9 (37.5%) 40 (36.4%) 0.917 Bifurcation involvement 64 (47.8%) 10 (41.7%) 54 (49.0%) 0.509 Occlusion duration (months), median [IQR] 12 [ 6 – 17 ] 12 [ 6 – 24 ] 9 [ 6 – 15 ] 0.278 CTO length (mm), median [IQR] 25 [18–40] 25 [20–41] 25 [15–40] 0.600 CTO length > 20 mm 92 (68.7%) 18 (75%) 74 (67.3%) 0.460 CTO bend ≥ 45° 64 (47.8%) 13 (54.2%) 51 (46.4%) 0.488 Blunt stump or no stump 66 (49.3%) 16 (66.7%) 50 (45.5%) 0.060 Proximal tortuosity (moderate–severe) 13 (9.7%) 3 (12.5%) 10 (9.1%) 0.609 Moderate/Severe calcification 52 (38.8%) 17 (70.8%) 35 (31.8%) < 0.001 Severe Distal vessel disease 57 (42.9%) 14 (58.3%) 43 (39.1%) 0.055 Collateral circulation CC0-CC1 55 (41%) 14 (58%) 41 (37%) 0.057 CC2-CC3 79 (59.0%) 10 (41.7%) 69 (62.7%) J-CTO score, median [IQR] 2 [ 1 – 3 ] 3 [ 2 – 4 ] 2 [ 1 – 3 ] 0.006 CTO : Chronic total occlusion. RCA : Right coronary artery. LAD : Left anterior descending artery. LCx : Left circumflex artery. LMT : Left main trunk. CABG : Coronary artery bypass grafting. PCI : Percutaneous coronary intervention. MI : Myocardial infarction. CC : Werner grading. J-CTO : Japanese Chronic Total Occlusion score. Procedural characteristics of the included patients are summarised in Table 3 . The final crossing wire most frequently belonged to the Fielder, Gaia families, and Gladius wires (Fig. 1 ). Stent implantation was performed in 97.2% of successful procedures, with a median of 1 stent per lesion [IQR 1–2] and a median total stent length of 49 mm [IQR 40–69]. Drug coated balloons were used in 10.9% of successful cases, mainly in combination with stenting. Table 3 Procedural characteristics of the included patients according to technical success Variable Category / Value Overall (N = 134) CTO failure (n = 24) CTO success (n = 110) p value Guiding catheter size 6F 33 (24.6%) 6 (25%) 27 (24.5%) 1.000 7F 94 (70.1%) 17 (70.8%) 77 (70%) ≥ 7.5F 7 (5.2%) 1 (4.1%) 6 (85.7%) Access site Radial 98 (73.1%) 15 (62.5%) 83 (75.5%) 0.195 Femoral 36 (26.9%) 9 (37.5%) 27 (24.54%) Dual injection 103 (76.9%) 18 (75%) 85 (77.27%) 0.811 Final crossing strategy Primarily antegrade 84 (62.7%) 11 (45.8%) 73 (66.36%) 0.06 Primarily retrograde 9 (6.7%) 2 (8.3%) 7 (6.36%) 0.727 Hybrid 41 (30.6%) 11 (45.8%) 30 (27.3%) 0.074 Previous CTO attempt 36 (26.9%) 7 (29.2%) 29 (26.4%) 0.78 Guide extension catheter 13 (9.7%) 3 (12.5%) 10 (9.1%) 0.61 IVUS use 3 (2.2%) 1 (4.2%) 2 (1.8%) 0.481 Rotational atherectomy 5 (3.7%) 0 (0%) 5 (4.5%) 0.287 Dual-lumen microcatheter 4 (3.0%) 1 (4.2%) 3 (2.7%) 0.707 Microcatheter use 113 (84.3%) 21 (87.5%) 92 (83.6%) 0.765 Tapered guidewire 100 (74.62%) 17 (70.8) 83 (75.5) 0.64 Total number of guidewires, median [IQR] 3 [ 2 – 4 ] 4 [ 3 – 6 ] 3 [ 2 – 4 ] 0.006 Procedural time (min) median [IQR] 120 [83.8–180] 150 [120–227.5] 120 [75.8–180] 0.005 Crossing time (min) median [IQR] 20 [5–50] 0 [0–33.8] 28.5 [10.8–54] < 0.001 Fluoroscopy time (min) median [IQR] 48 [30–81] 65.2 [48.7–110.5] 41 [28.8–71.3] 0.006 Contrast volume (ml) median [IQR] 180 [150–200] 190 [150–260] 180 [150–200] 0.228 Air kerma (mGy) median [IQR] 1993 [1180–3085] 2811 [1993–3628] 1890 [1081–2872] 0.010 Dose-area product (Gy·cm²) median [IQR] 11922 [7106–20802] 18323 [10488–20802] 11515 [7106–20223] 0.09 CTO : Chronic total occlusion. IVUS : Intravascular ultrasound. Gy·cm² : Gray–square centimetre. mGy : Milligray. A primary antegrade strategy was planned in 62.7% of procedures, and a primary retrograde strategy in 6.7%. The final successful crossing strategy remained primary antegrade in 62.7% of cases; however, strategy transition occurred frequently, reflecting implementation of a hybrid approach in 30.6% of cases. Successful antegrade recanalization was achieved in approximately 70% of antegrade attempts, including 50.8% via AWE and 10% via ADR. Among procedures requiring a retrograde approach (n = 50), retrograde wire crossing was achieved in 56%, with reverse CART employed in 38% of retrograde attempts. Septal collaterals constituted the predominant retrograde pathway (84%), most commonly CC2 collaterals (62%). Technical success was achieved in 110 procedures (82.1%), with TIMI 3 flow restoration in all successful cases. Overall procedural success was 81.3%. The primary mechanism of failure was inability to cross the occlusion with a guidewire (15.7%). Technical success improved significantly over time, increasing from 66.7% in 2022 to 88.8% in 2024 (linear-by-linear association χ² = 6.40, p = 0.011). Periprocedural complications occurred in 19 procedures (14.2%), corresponding to 24 total events, including 6 major complications (4.5%). Haemodynamic instability requiring catecholamine support was the most frequent complication (6.7%). Side-branch occlusion ≥ 2.5 mm occurred in 4.5%, stroke in 1.5%, coronary perforation without tamponade in 0.7%, donor artery dissection in 2.2%, and contrast-associated acute kidney injury in 2.2%. In-hospital MACCE occurred in 3 of 114 patients (2.63%). No urgent repeat revascularisation was recorded. Failed procedures were associated with moderate-to-severe calcification (70.8% vs 31.8%, p < 0.001), higher J-CTO score (median 3 vs 2, p = 0.006), poor collateral circulation (p = 0.057), and severely reduced LVEF ≤ 35% (40.0% vs 18.3%, p = 0.010). In multivariable analysis, the clinically relevant independent predictors of technical failure were J-CTO score ≥ 3 (OR 4.07, 95% CI 1.53–10.88, p = 0.005) and LVEF ≤ 35% (OR 3.90, 95% CI 1.38–11.04, p = 0.010). Follow-up was available for 73% of patients at twelve months. Median follow-up duration was 22 months [IQR 11–35]. MACCE occurred in 15 patients (13.2%), including 7 deaths and 8 myocardial infarctions. All-cause mortality was 6.1%. Kaplan–Meier analysis showed a twelve-month MACCE-free survival of 86.3% (95% CI 79.8–92.8%). MACCE incidence was significantly higher in patients with technical failure (60% vs 8.7%, log-rank p < 0.001). Reduced LVEF (≤ 35%) was associated with lower MACCE-free survival (log-rank p = 0.038). Target lesion failure occurred in 3 patients (2.6%), with a twelve-month TLF-free survival of 97.1% (95% CI 93.8–100.0%). No significant differences were observed according to LVEF category or technical success. Among symptomatic patients with paired follow-up data, significant improvement in angina severity was observed at twelve months. CCS class improved in 66 patients (81.5%) (p < 0.001), and NYHA functional class improved in 42 patients (51.9%) (p < 0.001). At twelve months, patients with successful CTO-PCI had significantly lower CCS class (median 1.0 vs 3.0, p = 0.013) and NYHA class (median 1.0 vs 2.0, p = 0.011) compared with those with technical failure. Discussion This prospective single-centre study describes the early evolution of a CTO-PCI programme in a North African low- to middle-income centre. Across 134 procedures, technical success reached 82.1% and improved significantly over time, approaching 90% in the final year, consistent with a learning-curve effect. Lesion complexity (J-CTO ≥ 3) and severely reduced left ventricular ejection fraction (LVEF ≤ 35%) independently predicted technical failure. Periprocedural complication rates were acceptable, and twelve-month MACCE-free survival and symptomatic improvement were substantial. These findings demonstrate that structured CTO-PCI programmes can achieve registry-comparable outcomes in emerging centres despite intermediate-to-high anatomical complexity. Compared with contemporary international CTO registries, the Farhat Hached cohort reflects a higher-risk clinical profile despite broadly comparable demographic characteristics. Mean age (60.9 ± 9.1 years) was similar to that reported in MENATA (≈ 61 years) and PROGRESS-CTO cohorts (≈ 65years) [ 13 , 14 ]. Male predominance (84.2%) was also consistent with global CTO populations, where male representation typically exceeds 80% [ 15 , 16 ]. However, the burden of cardiovascular risk factors was notable. Diabetes mellitus was present in 60.5% of patients—substantially higher than rates reported in many Western registries (typically 35–45%) and slightly higher than MENATA [ 13 – 15 , 17 ]. Smoking prevalence (72.8%) was likewise elevated compared with European datasets [ 18 ]. These findings likely reflect regional epidemiology and may contribute to greater diffuse coronary disease and calcification burden. A history of prior myocardial infarction (60.5%) and prior PCI (57.0%) mirrored rates reported in expert registries, reflecting established coronary disease and prior revascularisation exposure. In contrast, prior coronary artery bypass grafting was uncommon (5.3%), similar to contemporary datasets [ 13 , 15 ] Mean LVEF (43.9%) was lower than typically described in selected randomised CTO trials and cohorts. Severe LV dysfunction (LVEF ≤ 35%) was present in 20.2% of patients, markedly higher than proportions reported in ERCTO (7.6%) and OPEN-CTO (13.7%), suggesting inclusion of a more clinically vulnerable population [ 15 , 19 ]. Regarding clinical presentation, stable angina predominated (76.3%), consistent with elective CTO practice in OPEN-CTO, PROGRESS-CTO, and MENATA cohorts [ 13 – 15 ]. Importantly, angina severity was substantial at baseline, with 78.2% classified as CCS III–IV, representing a higher symptomatic burden than reported in OPEN-CTO (72.4%) and PROGRESS-CTO (63.6%). These features position the cohort as clinically higher-risk compared with many Western series and provide essential context for interpreting procedural success and mid-term outcomes. From an angiographic perspective, target vessels’ distribution differed from several international datasets. Whereas OPEN-CTO, PROGRESS-CTO, EURO-CTO, and MENATA registries reported right coronary artery predominance (55–64%), the Farhat Hached cohort demonstrated a higher proportion of left anterior descending (LAD) CTOs (47%). This distinction is clinically relevant, as LAD CTOs subtend a larger myocardial territory and may carry greater prognostic implications [ 13 – 16 ]. Median J-CTO score was 2 (IQR 1–3), indicating intermediate lesion complexity, comparable to MENATA (≈ 2.1) and PROGRESS-CTO (2.43 ± 1.30), and higher than that observed in the EURO-CTO PCI arm (1.82 ± 1.07), reflecting the inclusion of a less selected and anatomically more complex cohort [ 13 – 16 ]. Lesion length (median 25 mm) was slightly shorter than MENATA (≈ 30 mm), although moderate-to-severe calcification was observed in 38.8% of lesions, exceeding rates in several western and regional registries and suggesting a greater burden of advanced atherosclerosis [ 14 , 16 , 20 ]. Bifurcation involvement (47.8%) was also frequent and higher than reported in ERCTO, reinforcing anatomical complexity [ 20 ]. Collateral patterns were broadly comparable to international experience, with CC2–3 collaterals present in approximately 59% of cases, similar to PROGRESS-CTO (56.7%) but lower than ERCTO (89.7%) [ 13 , 20 ]. In-stent CTO prevalence (11.9%) was lower than in some international cohorts, suggesting predominance of de novo occlusions [ 14 , 21 ]. Overall, the angiographic profile aligns with contemporary real-world CTO practice and supports interpretation of procedural success within an appropriate anatomical framework. Radial access predominated in the Farhat Hached cohort (73.1%), exceeding rates reported in major CTO registries and reflecting strong radial proficiency even in complex lesions [ 13 , 14 , 20 ]. Dual arterial injection was frequently employed (76.9%), consistent with contemporary European practice and supporting optimal lesion visualisation [ 16 , 20 ]. An antegrade-first strategy remained dominant (≈ 63%), while retrograde techniques were used in over one-third of procedures, aligning with modern hybrid practice patterns. Hybrid strategy adoption (30.6%) demonstrates adherence to contemporary CTO algorithms and likely contributed to the progressive improvement in technical success observed over time. Technical success (82.1%) aligns with contemporary real-world CTO registries, though slightly lower than large expert cohorts such as PROGRESS-CTO (≈ 87%) and the Japanese CTO-PCI Expert Registry (≈ 92%) [ 13 , 21 ]. Compared with MENATA (≈ 91%), the modest difference may reflect multicentre expert participation and broader access to intravascular imaging [ 14 ]. Nevertheless, lesion complexity was comparable across cohorts, supporting the feasibility of CTO-PCI in a North African middle-income setting. High lesion complexity (J-CTO ≥ 3) independently predicted technical failure (OR 4.07), aligning with PROGRESS-CTO findings showing a two-fold increase in failure per point increase in J-CTO score and supported by meta-analytic data validating its strong predictive value for procedural difficulty. [ 11 , 22 ]. Severely reduced left ventricular function (LVEF ≤ 35%) also independently predicted failure (OR 3.90). Although expert registries report similar technical success across LVEF strata, patients with impaired ventricular function consistently exhibit higher clinical risk [ 23 ]. The higher prevalence of severe systolic dysfunction in the Farhat Hached cohort, combined with limited access to routine mechanical circulatory support, may explain its procedural impact in this setting. Thus, in middle-income centres, ventricular dysfunction may exert a more tangible influence on technical outcome than in high-volume expert institutions In-hospital MACCE (2.6%) falls within the 1.7–3% range reported in PROGRESS-CTO and ERCTO registries [ 13 , 20 ]. Although overall periprocedural complications were numerically higher (14.2%), this reflects comprehensive event capture, whereas registry definitions vary. Major complications (4.5%) remain within contemporary real-world ranges (3–10%) [ 24 , 25 ]. Thus, procedural safety was comparable to international standards despite intermediate-to-high lesion complexity and limited intravascular imaging utilisation. At twelve months, MACCE occurred in 13.2% of patients. This rate is comparable to mid-term event rates reported in OPEN-CTO (≈ 10%) and other all-comer registries, though higher than the 5.2% reported in the EURO-CTO PCI arm, which included more selected populations [ 15 , 16 ]. Kaplan–Meier analysis demonstrated significantly lower event rates among patients with successful recanalization, mirroring findings from PROGRESS-CTO, where lower MACE rates were observed following successful CTO recanalization compared with technical failure [ 26 ]. These findings reinforce the clinically meaningful association between technical success and improved mid-term outcomes. Target lesion failure (2.6%) was consistent with contemporary drug-eluting stent performance and comparable to TLR/TLF rates reported in EURO-CTO and RECHARGE registries [ 16 , 27 ]. Symptomatic improvement was substantial and clearly success-dependent, with 81.5% of patients demonstrating CCS improvement at twelve months. This parallels the EURO-CTO randomised trial, which showed significant angina reduction and improved quality of life following CTO-PCI compared with optimal medical therapy [ 16 ]. Although symptom assessment in EURO-CTO relied on validated patient-reported instruments rather than CCS or NYHA classification, the overall pattern of benefit closely mirrors the present findings. Further concordance is seen in the UK hybrid CTO experience reported by Wilson et al., where 88% of successfully treated patients were free of angina or minimally symptomatic at twelve months [ 28 ]. Unlike the MENATA regional dataset, our study incorporated structured CCS and NYHA follow-up, providing patient-centred outcome data beyond angiographic success [ 14 ]. Within the national context, the Farhat Hached cohort demonstrated higher rates of severe LV dysfunction and greater lesion complexity compared with La Rabta and Habib Thameur CTO cohorts. Despite this, technical success was numerically higher (82.1% vs 79.3% and 69.2%). Greater adoption of dual access, microcatheters, and hybrid escalation strategies likely contributed to these differences. Importantly, Farhat Hached is the only Tunisian cohort to provide systematic twelve-month MACCE and symptom follow-up, enabling assessment of sustained clinical benefit beyond procedural metrics [ 29 , 30 ]. Data on CTO-PCI from North Africa remain scarce. This study provides prospective real-world evidence demonstrating that structured hybrid CTO-PCI can achieve registry-level safety and efficacy in a low- to middle-income healthcare setting. Despite inclusion of higher-risk patients and resource constraints, outcomes approached those of established international registries, supporting expansion of contemporary CTO programmes in similar environments. Conclusion In this prospective single-centre study, implementation of a contemporary hybrid CTO-PCI programme in a North African low- to middle-income centre achieved technical success rates comparable to major international registries despite a clinically higher-risk population with elevated diabetes prevalence, substantial symptomatic burden, and frequent severe left ventricular dysfunction. Technical success improved significantly over time, approaching 90% in the final year, reflecting operator experience and structured adoption of hybrid strategies. Lesion complexity (J-CTO ≥ 3) independently predicted technical failure, consistent with global data, while severely reduced LVEF also emerged as an independent determinant, suggesting that ventricular dysfunction may exert greater procedural impact in resource-constrained settings. Procedural safety was acceptable, with in-hospital MACCE within contemporary registry ranges and low twelve-month target lesion failure. Successful recanalization was strongly associated with improved mid-term outcomes and marked symptomatic relief, reinforcing the clinical value of CTO-PCI beyond angiographic endpoints. These findings support the feasibility and scalability of modern CTO programmes in similar healthcare environments and contribute meaningful prospective data from an underrepresented region. Abbreviations CTO: Chronic total occlusion PCI: Percutaneous coronary intervention CTO-PCI: Chronic total occlusion percutaneous coronary intervention TIMI: Thrombolysis in Myocardial Infarction MACCE: Major adverse cardiac and cerebrovascular events TLF: Target lesion failure LVEF: Left ventricular ejection fraction CCS: Canadian Cardiovascular Society NYHA: New York Heart Association J-CTO: Japanese Chronic Total Occlusion score IVUS: Intravascular ultrasound ADR: Antegrade dissection and re-entry AWE: Antegrade wire escalation Declarations Data availability The data used in this study can be obtained from corresponding author, Ben Abdessalem Mohamed Aymen ( [email protected] ) upon reasonable request. Acknowledgements: The authors thank the medical and nursing staff of the Cardiology Department of Farhat Hached University Hospital for their contribution to patient care. Funding This study was not supported by any sponsor or funder. Author information Department of Cardiology, Farhat Hached University Hospital, Sousse, Tunisia. Contributions M.A.B.A. and J.B conceived the study, collected data, performed analysis, and drafted the manuscript. Z.B.A., H.F., M.Y., and A.M. contributed to data collection, interpretation, and manuscript revision. All authors read and approved the final manuscript. Corresponding author Correspondence to Mohamed Aymen Ben Abdessalem. Funding: No funding was provided during this observational prospective study. Ethics statement : This prospective observational study was approved by the Research Ethics Committee of Farhat Hached University Hospital and the Faculty of Medicine of Sousse. Written informed consent was obtained from all participants. The study was conducted in accordance with the principles of the Declaration of Helsinki. Consent for publication : Not applicable. Competing interests : The authors declare no competing interests. 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JACC: Cardiovascular Interventions. 2017 Aug;10(15):1523–34. doi:10.1016/j.jcin.2017.05.065 Werner GS, Martin-Yuste V, Hildick-Smith D, Boudou N, Sianos G, Gelev V, et al. A randomized multicentre trial to compare revascularization with optimal medical therapy for the treatment of chronic total coronary occlusions. European Heart Journal. 2018 Jul 7;39(26):2484–93. doi:10.1093/eurheartj/ehy220 Azzalini L, Jolicoeur EM, Pighi M, Millán X, Picard F, Tadros VX, et al. Epidemiology, Management Strategies, and Outcomes of Patients With Chronic Total Coronary Occlusion. Am J Cardiol. 2016 Oct 15;118(8):1128–35. doi:10.1016/j.amjcard.2016.07.023 PubMed PMID: 27561190. Hannan EL, Zhong Y, Jacobs AK, Stamato NJ, Berger PB, Walford G, et al. Patients With Chronic Total Occlusions Undergoing Percutaneous Coronary Interventions: Characteristics, Success, and Outcomes. Circ: Cardiovascular Interventions. 2016 May;9(5):e003586. doi:10.1161/CIRCINTERVENTIONS.116.003586 Galassi A, Tomasello S, Reifart N, Werner G, Sianos G, Bonnier H, et al. In-hospital outcomes of percutaneous coronary intervention in patients with chronic total occlusion: insights from the ERCTO (European Registry of Chronic Total Occlusion) registry [Internet]. [cited 2026 Jan 7]. Available from: https://eurointervention.pcronline.com/article/in-hospital-outcomes-of-percutaneous-coronary-intervention-in-patients-with-chronic-total-occlusion-insights-from-the-ercto-european-registry-of-chronic-total-occlusion-registry doi:10.4244/EIJV7I4A77 Percutaneous recanalisation of chronic total occlusions: 2019 consensus document from the EuroCTO Club | EuroIntervention [Internet]. [cited 2026 Jan 3]. Available from: https://eurointervention.pcronline.com/article/percutaneous-recanalization-of-chronic-total-occlusions-2019-consensus-document-from-the-eurocto-club Suzuki Y, Tsuchikane E, Katoh O, Muramatsu T, Muto M, Kishi K, et al. Outcomes of Percutaneous Coronary Interventions for Chronic Total Occlusion Performed by Highly Experienced Japanese Specialists. JACC: Cardiovascular Interventions. 2017 Nov;10(21):2144–54. doi:10.1016/j.jcin.2017.06.024 Zuo W, Lin J, Sun R, Su Y, Ma G. Performance of the J-CTO score versus other risk scores for predicting procedural difficulty in coronary chronic total occlusion interventions. Ann Med. 54(1):3117–28. doi:10.1080/07853890.2022.2141466 PubMed PMID: 36322535; PubMed Central PMCID: PMC9635461. Sapontis J, Hirai T, Patterson C, Gans B, Yeh RW, Lombardi W, et al. Intermediate procedural and health status outcomes and the clinical care pathways after chronic total occlusion angioplasty: A report from the OPEN‐CTO (outcomes, patient health status, and efficiency in chronic total occlusion hybrid procedures) study. Catheter Cardiovasc Interv. 2020 Oct 27;ccd.29343. doi:10.1002/ccd.29343 Simsek B, Kostantinis S, Karacsonyi J, Alaswad K, Krestyaninov O, Khelimskii D, et al. Predicting Periprocedural Complications in Chronic Total Occlusion Percutaneous Coronary Intervention. JACC: Cardiovascular Interventions. 2022 Jul;15(14):1413–22. doi:10.1016/j.jcin.2022.06.007 Simsek B, Kostantinis S, Karacsonyi J, Brilakis ES. Scores for Chronic Total Occlusion Percutaneous Coronary Intervention: A Window to the Future? J Am Heart Assoc. 2022 May 16;11(10):e026070. doi:10.1161/JAHA.122.026070 PubMed PMID: 35574966; PubMed Central PMCID: PMC9238564. Xenogiannis I, Karmpaliotis D, Krestyaninov O, Khelimskii D, Khatri J, Alaswad K, et al. FOLLOW-UP OUTCOMES AFTER CHRONIC TOTAL OCCLUSION PERCUTANEOUS CORONARY INTERVENTION: DOES SUCCESSFUL REVASCULARIZATION MATTER ? Journal of the American College of Cardiology. 2020 Mar;75(11):1296. doi:10.1016/S0735-1097(20)31923-9 Maeremans J, Walsh S, Knaapen P, Spratt JC, Avran A, Hanratty CG, et al. The Hybrid Algorithm for Treating Chronic Total Occlusions in Europe. Journal of the American College of Cardiology. 2016 Nov;68(18):1958–70. doi:10.1016/j.jacc.2016.08.034 Wilson WM, Walsh SJ, Bagnall A, Yan AT, Hanratty CG, Egred M, et al. One‐year outcomes after successful chronic total occlusion percutaneous coronary intervention: The impact of dissection re‐entry techniques. Cathet Cardio Intervent. 2017 Nov;90(5):703–12. doi:10.1002/ccd.26980 BADER M. Percutaneous Coronary Intervention of Coronary Chronic Total Occlusion: In-Hospital and Long-Term Outcomes. [Tunis, Tunisia]: Tunis El Manar University – Faculty of Medicine of Tunis; 2024. Lamine H, Bouzidi H, Hammami S, Saidane S, Iddir S, Kraiem S. Angioplastie des occlusions totales chroniques : Rapport de cinq ans d’expérience dans un centre Tunisien multi-opérateurs. Tunis Med. 2025 Jan;103(1):142–51. doi:10.62438/tunismed.v103i1.4940 PubMed PMID: 39812208; PubMed Central PMCID: PMC11906239. Additional Declarations No competing interests reported. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-9113443","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":627757809,"identity":"2fc66d37-eaba-40b8-85da-592ed25b29c4","order_by":0,"name":"Mohamed Aymen Ben Abdessalem","email":"data:image/png;base64,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","orcid":"","institution":"University of Sousse","correspondingAuthor":true,"prefix":"","firstName":"Mohamed","middleName":"Aymen Ben","lastName":"Abdessalem","suffix":""},{"id":627757811,"identity":"a2ccbced-65e6-452a-97ef-166f29e88f6e","order_by":1,"name":"Jaouaher Benhafsa","email":"","orcid":"","institution":"University of Sousse","correspondingAuthor":false,"prefix":"","firstName":"Jaouaher","middleName":"","lastName":"Benhafsa","suffix":""},{"id":627757812,"identity":"36335096-c074-417b-a245-a46c896c8016","order_by":2,"name":"Zied Ben Ameur","email":"","orcid":"","institution":"University of Sousse","correspondingAuthor":false,"prefix":"","firstName":"Zied","middleName":"Ben","lastName":"Ameur","suffix":""},{"id":627757813,"identity":"4237d135-2a56-427e-9c24-7645c971947b","order_by":3,"name":"Hedi Frigui","email":"","orcid":"","institution":"University of Sousse","correspondingAuthor":false,"prefix":"","firstName":"Hedi","middleName":"","lastName":"Frigui","suffix":""},{"id":627757814,"identity":"aadf9dde-ee27-4b76-b223-53b425c5fb8e","order_by":4,"name":"Abdallah Mahdhaoui","email":"","orcid":"","institution":"University of Sousse","correspondingAuthor":false,"prefix":"","firstName":"Abdallah","middleName":"","lastName":"Mahdhaoui","suffix":""}],"badges":[],"createdAt":"2026-03-13 10:11:07","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9113443/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9113443/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":107650627,"identity":"773c9d3f-77c9-4c5a-9157-5be084d225f8","added_by":"auto","created_at":"2026-04-23 15:01:56","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":27834,"visible":true,"origin":"","legend":"\u003cp\u003eDistribution of Guidewires Used for Successful CTO Crossing\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-9113443/v1/79ff73c20fe74970daa239c3.png"},{"id":107707114,"identity":"d482691a-5260-40be-8d12-ad47ec63e9eb","added_by":"auto","created_at":"2026-04-24 09:19:33","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":118963,"visible":true,"origin":"","legend":"\u003cp\u003eChange in CCS Class after CTO-PCI\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-9113443/v1/9aa31da38701f0326d6e7933.png"},{"id":107709099,"identity":"2683d518-81f3-482b-97b3-0dac38de4c85","added_by":"auto","created_at":"2026-04-24 09:34:48","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":603081,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9113443/v1/b0d4eadc-10c2-436e-86a8-0cc2bbdc34bd.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Hybrid algorithm CTO-PCI in a Resource-Constrained Tunisian Center","fulltext":[{"header":"Introduction","content":"\u003cp\u003eChronic total occlusion (CTO), defined as a complete coronary artery obstruction with TIMI 0 flow of presumed duration\u0026thinsp;\u0026ge;\u0026thinsp;3 months, represents one of the most complex subsets of coronary artery disease. CTOs are identified in approximately 15\u0026ndash;20% of patients undergoing coronary angiography and are particularly prevalent among individuals with ischemic cardiomyopathy and reduced left ventricular ejection fraction [\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e].\u003c/p\u003e \u003cp\u003ePercutaneous coronary intervention for CTO (CTO-PCI) remains technically demanding and has historically been associated with lower procedural success rates and increased complication risk compared with non-occlusive lesions [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Over the past decade, however, advances in dedicated devices, refinement of antegrade and retrograde techniques, and structured hybrid approach implementation have markedly improved success rates in experienced centres [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eAlthough composite event-based outcomes such as major adverse cardiac and cerebrovascular events (MACCE) are commonly reported, symptom relief and functional improvement remain the primary clinical drivers for CTO revascularisation [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Contemporary guidelines therefore recommend CTO-PCI mainly in patients with persistent angina despite optimal medical therapy and objective evidence of ischemia or viability in the CTO-related territory [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eDespite these advances, most available data originate from North American, European, or East Asian registries. Evidence from North Africa is extremely limited, and prospective evaluations of procedural and technical success, safety, and patient-centred outcomes in Tunisian populations are scarce. Differences in demographic characteristics, comorbidity burden, healthcare resources, and interventional practice patterns may influence outcomes and limit the generalisability of international data to this region [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eFarhat Hached University Hospital in Sousse has developed a dedicated CTO program with progressive adoption of contemporary revascularisation strategies. Evaluating outcomes from this centre provides an opportunity to generate locally relevant data and to benchmark Tunisian results against established international registries.\u003c/p\u003e \u003cp\u003eTo address this regional evidence gap, we conducted a prospective observational study between January 2022 and December 2024 to evaluate real-world outcomes of CTO-PCI in a Tunisian cohort. The primary objective was to assess immediate procedural outcomes and determinants of technical success. The secondary objective was to evaluate twelve-month clinical and functional outcomes, including MACCE, target lesion failure, and changes in angina severity.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003eWe prospectively analysed 114 patients who underwent 134 CTO-PCI procedures between 1 January 2022 and 31 December 2024 at the Cardiology Department of Farhat Hached University Hospital, Sousse, Tunisia. Data were collected in real time using standardised case report forms and cross-verified against medical and catheterisation laboratory records.\u003c/p\u003e \u003cp\u003eCTO was defined according to CTO-ARC criteria as angiographic TIMI 0 antegrade flow with an estimated duration\u0026thinsp;\u0026ge;\u0026thinsp;3 months. Indications for CTO-PCI were consistent with contemporary ESC and Euro-CTO recommendations and were confirmed following multidisciplinary evaluation [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Patients were eligible if aged 18\u0026ndash;85 years with angiographically confirmed CTO and guideline-based indications, including persistent angina despite optimal medical therapy, objective ischaemia (\u0026ge;\u0026thinsp;10% of left ventricular myocardium), or evidence of viable myocardium in the CTO territory [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Selected ST-segment elevation myocardial infarction patients with concomitant non-infarct-related artery CTO undergoing complete revascularisation were also included [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Written informed consent was obtained from all participants. Exclusion criteria comprised non-viable myocardium, cardiogenic shock, contraindication to dual antiplatelet therapy or iodinated contrast, and inability to complete follow-up. Baseline variables included demographics, cardiovascular risk factors, prior cardiac events, renal function, and clinical presentation. Symptom severity was assessed using the Canadian Cardiovascular Society (CCS) angina classification and the New York Heart Association (NYHA) functional class [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Left ventricular ejection fraction was measured using Simpson\u0026rsquo;s method and categorised as preserved (\u0026ge;\u0026thinsp;50%), moderately reduced (35\u0026ndash;50%), or severely reduced (\u0026le;\u0026thinsp;35%). Coronary angiograms were independently reviewed by two experienced operators. Recorded variables included target vessel, lesion morphology, calcification, collateral grade (Werner classification), and lesion complexity assessed using the J-CTO score (\u0026lt;\u0026thinsp;3 vs\u0026thinsp;\u0026ge;\u0026thinsp;3) [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. CTO-PCI was performed using a contemporary hybrid strategy allowing transition between antegrade and retrograde techniques. Access site, crossing strategy, devices used, procedure duration, fluoroscopy time, and contrast volume were documented. Technical success was defined as restoration of TIMI 3 antegrade flow with \u0026lt;\u0026thinsp;30% residual stenosis [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Procedural success was defined as technical success without in-hospital major adverse cardiac and cerebrovascular events (MACCE) [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. In-hospital MACCE, assessed at patient level, included death, stroke, myocardial infarction, or urgent repeat revascularisation. Major procedural complications, assessed at procedure level, included peri-procedural death, stroke, myocardial infarction, collateral perforation with tamponade, acute stent thrombosis, donor vessel dissection, and major vascular complications. Patients were systematically followed for twelve months. The primary endpoint was immediate technical and procedural success and its determinants. Secondary endpoints included twelve-month MACCE, target lesion failure, and change in CCS and NYHA class, with clinical improvement defined as a reduction of at least one class. Statistical analyses were performed using IBM SPSS Statistics version 25.0. Normality was assessed using the Shapiro\u0026ndash;Wilk test. Continuous variables were compared using Student\u0026rsquo;s t-test for normally distributed data or the Mann\u0026ndash;Whitney U test for non-normal distributions. Categorical variables were analysed using the χ\u0026sup2; test or Fisher\u0026rsquo;s exact test as appropriate. Paired pre- and post-procedural comparisons of CCS and NYHA class were performed using the Wilcoxon signed-rank test. Kaplan\u0026ndash;Meier analysis was used to estimate MACCE-free and target lesion failure-free survival, with comparisons performed using the log-rank test. Patients were censored at the time of last follow-up or event occurrence. Variables with p\u0026thinsp;\u0026lt;\u0026thinsp;0.20 in univariate analysis that were considered clinically relevant were entered into a multivariable logistic regression model to identify independent predictors of technical success. Results are reported as odds ratios with 95% confidence intervals. All statistical tests were two-sided, and a p-value\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered statistically significant.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eDuring the study period, 114 patients underwent 134 CTO-PCI procedures involving 121 CTO lesions. Overall catheterisation laboratory activity increased substantially, with CTO-PCI procedures rising from 18 in 2022 to 80 in 2024, representing approximately 7% of all PCI procedures in the final year.\u003c/p\u003e \u003cp\u003eBaseline clinical characteristics are summarised in Table. Stable angina was the predominant presentation (76.3%) with most patients experiencing high symptom burden per Canadian Cardiovascular Society (CCS) grading, predominantly CCS III (59.8%) and CCS IV (18.4%). A small proportion (2.6%) were asymptomatic for angina but presented with dyspnoea. Among clinically stable patients, angina severity was predominantly moderate to severe, with 78.2% classified as CCS class III\u0026ndash;IV. Functional limitation was less pronounced, with 21.8% in NYHA class III\u0026ndash;IV. Left ventricular systolic function was preserved (LVEF\u0026thinsp;\u0026ge;\u0026thinsp;50%) in 52.6% of patients, moderately reduced (35\u0026ndash;50%) in 27.2%, and severely reduced (\u0026le;\u0026thinsp;35%) in 20.2%, with a mean LVEF of 43.9\u0026thinsp;\u0026plusmn;\u0026thinsp;12.9%. Regional wall motion assessment showed hypokinesia in 71.1% of CTO territories, normal motion in 25.6%, and akinesia in 3.3%, with no dyskinesia observed.\u003c/p\u003e \u003cp\u003eAngiographic characteristics of the included patients are summarised in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. Multivessel coronary artery disease (\u0026ge;\u0026thinsp;2 diseased vessels) was identified in 86 patients (75.4%).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eBaseline clinical characteristics of the included patients according to technical success\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariable\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOverall (N\u0026thinsp;=\u0026thinsp;114)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNot successful (n\u0026thinsp;=\u0026thinsp;10)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eSuccessful (n\u0026thinsp;=\u0026thinsp;104)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003ep value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge (years)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e60.9\u0026thinsp;\u0026plusmn;\u0026thinsp;9.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e64.6\u0026thinsp;\u0026plusmn;\u0026thinsp;10.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e60.5\u0026thinsp;\u0026plusmn;\u0026thinsp;9.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.17\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale gender\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e96 (84.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8 (80.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e88 (84.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.70\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCurrent smoker and former smoker\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e83 (72.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4 (40.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e79 (76.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e0.002\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDiabetes mellitus (NID/ID)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e69 (60.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8 (80.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e61 (58.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.19\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHypertension\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e66 (57.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5 (50.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e61 (58.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.60\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDyslipidaemia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e79 (69.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6 (60.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e73 (70.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.51\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eObesity\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e14 (12.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 (0.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e14 (13.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.22\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePeripheral arterial disease\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e24 (21.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (10.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e23 (22.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.37\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCOPD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5 (4.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 (0.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5 (4.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRenal failure on dialysis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2 (1.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 (0.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2 (1.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.66\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePrior stroke\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3 (2.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 (0.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3 (2.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e \u003cp\u003eClinical presentation\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStable angina\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e80 (70.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5 (50.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e75 (72.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003e0.31\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eACS (UA\u0026thinsp;+\u0026thinsp;MI)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e29 (25.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4 (40.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e25 (24.0%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDyspnoea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5 (4.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (10.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4 (3.9%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e \u003cp\u003ePrior PCI/CABG/MI history\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePrevious myocardial infarction (overall)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e72 (63.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7 (70.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e65 (62.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.64\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePrevious MI in CTO territory\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e29 (25.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4 (40.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e25 (24.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.27\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePrevious PCI\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e68 (59.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6 (60.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e62 (59.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.98\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePrevious PCI in CTO territory (re-occlusion)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e17 (14.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (10.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e16 (15.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.65\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePrevious CABG\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6 (5.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (10.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5 (4.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.48\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePrevious CABG in CTO territory\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5 (4.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (10.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4 (3.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.36\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e \u003cp\u003eLeft Ventricular Ejection Fraction (LVEF)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u0026le;\u0026thinsp;35%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e23 (20.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4 (40.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e19 (18.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e\u003cb\u003e0.010\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u0026gt;\u0026thinsp;35%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e91 (79.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6 (60.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e85 (81.7%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e \u003cp\u003eACS: Acute coronary syndrome. UA: Unstable angina. MI: Myocardial infarction. STEMI: ST-segment elevation myocardial infarction. NSTEMI: Non\u0026ndash;ST segment elevation myocardial infarction. COPD: Chronic obstructive pulmonary disease. BMI: Body mass index. CABG: Coronary artery bypass graft surgery. CTO: Chronic total occlusion. PCI: Percutaneous coronary intervention. LVEF: Left ventricular ejection fraction.\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eAngiographic characteristics of the included patients according to technical success\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"12\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c11\" colnum=\"11\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c12\" colnum=\"12\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003eVariable\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c5\" namest=\"c3\"\u003e \u003cp\u003eCategory / Value\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eOverall (N\u0026thinsp;=\u0026thinsp;134)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cp\u003eNot successful (n\u0026thinsp;=\u0026thinsp;24)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c11\" namest=\"c9\"\u003e \u003cp\u003eSuccessful (n\u0026thinsp;=\u0026thinsp;110)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c12\"\u003e \u003cp\u003ep value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eNumber of diseased vessels (including CTO)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e \u003cp\u003e1 vessel\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c7\" namest=\"c5\"\u003e \u003cp\u003e28 (24.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c9\" namest=\"c8\"\u003e \u003cp\u003e2 (20.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e26 (25.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" morerows=\"2\" nameend=\"c12\" namest=\"c11\" rowspan=\"3\"\u003e \u003cp\u003e0.74\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e \u003cp\u003e2 vessels\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c7\" namest=\"c5\"\u003e \u003cp\u003e42 (36.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c9\" namest=\"c8\"\u003e \u003cp\u003e3 (30.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e26 (25.0%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e \u003cp\u003e3 vessels\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c7\" namest=\"c5\"\u003e \u003cp\u003e44 (38.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c9\" namest=\"c8\"\u003e \u003cp\u003e5 (50.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e39 (37.5%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" morerows=\"4\" nameend=\"c2\" namest=\"c1\" rowspan=\"5\"\u003e \u003cp\u003eCTO artery\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c5\" namest=\"c3\"\u003e \u003cp\u003eLMT\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e3 (2.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cp\u003e1 (4.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c11\" namest=\"c9\"\u003e \u003cp\u003e2 (1.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\" morerows=\"4\" rowspan=\"5\"\u003e \u003cp\u003e0.637\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c5\" namest=\"c3\"\u003e \u003cp\u003eLAD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e63 (47.01%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cp\u003e14 (58.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c11\" namest=\"c9\"\u003e \u003cp\u003e49 (44.5%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c5\" namest=\"c3\"\u003e \u003cp\u003eLCx\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e14 (10.44%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cp\u003e2 (8.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c11\" namest=\"c9\"\u003e \u003cp\u003e12 (10.9%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c5\" namest=\"c3\"\u003e \u003cp\u003eRCA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e52 (38.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cp\u003e7 (29.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c11\" namest=\"c9\"\u003e \u003cp\u003e45 (40.9%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c5\" namest=\"c3\"\u003e \u003cp\u003eSB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2 (1.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cp\u003e0 (0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c11\" namest=\"c9\"\u003e \u003cp\u003e2 (1.8%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" morerows=\"3\" nameend=\"c2\" namest=\"c1\" rowspan=\"4\"\u003e \u003cp\u003eCTO location\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c5\" namest=\"c3\"\u003e \u003cp\u003eOstial\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e15 (11.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cp\u003e4 (16.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c11\" namest=\"c9\"\u003e \u003cp\u003e11 (1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\" morerows=\"3\" rowspan=\"4\"\u003e \u003cp\u003e0.710\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c5\" namest=\"c3\"\u003e \u003cp\u003eProximal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e53 (39.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cp\u003e10 (41.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c11\" namest=\"c9\"\u003e \u003cp\u003e43 (39%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c5\" namest=\"c3\"\u003e \u003cp\u003eMid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e60 (44.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cp\u003e9 (37.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c11\" namest=\"c9\"\u003e \u003cp\u003e51 (46.4%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c5\" namest=\"c3\"\u003e \u003cp\u003eDistal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e6 (4.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cp\u003e1 (4.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c11\" namest=\"c9\"\u003e \u003cp\u003e5 (0.45%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e \u003cp\u003eIn-stent CTO\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e16 (11.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cp\u003e1 (4.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c11\" namest=\"c9\"\u003e \u003cp\u003e15 (13.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e0.195\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e \u003cp\u003e\u0026gt;\u0026thinsp;1 CTO segment\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e49 (36.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cp\u003e9 (37.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c11\" namest=\"c9\"\u003e \u003cp\u003e40 (36.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e0.917\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e \u003cp\u003eBifurcation involvement\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e64 (47.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cp\u003e10 (41.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c11\" namest=\"c9\"\u003e \u003cp\u003e54 (49.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e0.509\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e \u003cp\u003eOcclusion duration (months), median [IQR]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e12 [\u003cspan additionalcitationids=\"CR7 CR8 CR9 CR10 CR11 CR12 CR13 CR14 CR15 CR16\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cp\u003e12 [\u003cspan additionalcitationids=\"CR7 CR8 CR9 CR10 CR11 CR12 CR13 CR14 CR15 CR16 CR17 CR18 CR19 CR20 CR21 CR22 CR23\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c11\" namest=\"c9\"\u003e \u003cp\u003e9 [\u003cspan additionalcitationids=\"CR7 CR8 CR9 CR10 CR11 CR12 CR13 CR14\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e0.278\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e \u003cp\u003eCTO length (mm), median [IQR]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e25 [18\u0026ndash;40]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cp\u003e25 [20\u0026ndash;41]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c11\" namest=\"c9\"\u003e \u003cp\u003e25 [15\u0026ndash;40]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e0.600\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e \u003cp\u003eCTO length\u0026thinsp;\u0026gt;\u0026thinsp;20 mm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e92 (68.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cp\u003e18 (75%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c11\" namest=\"c9\"\u003e \u003cp\u003e74 (67.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e0.460\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e \u003cp\u003eCTO bend\u0026thinsp;\u0026ge;\u0026thinsp;45\u0026deg;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e64 (47.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cp\u003e13 (54.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c11\" namest=\"c9\"\u003e \u003cp\u003e51 (46.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e0.488\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e \u003cp\u003eBlunt stump or no stump\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e66 (49.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cp\u003e16 (66.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c11\" namest=\"c9\"\u003e \u003cp\u003e50 (45.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e\u003cb\u003e0.060\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e \u003cp\u003eProximal tortuosity (moderate\u0026ndash;severe)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e13 (9.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cp\u003e3 (12.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c11\" namest=\"c9\"\u003e \u003cp\u003e10 (9.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e0.609\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e \u003cp\u003eModerate/Severe calcification\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e52 (38.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cp\u003e17 (70.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c11\" namest=\"c9\"\u003e \u003cp\u003e35 (31.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e \u003cp\u003eSevere Distal vessel disease\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e57 (42.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cp\u003e14 (58.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c11\" namest=\"c9\"\u003e \u003cp\u003e43 (39.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e0.055\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"3\" morerows=\"1\" nameend=\"c3\" namest=\"c1\" rowspan=\"2\"\u003e \u003cp\u003eCollateral circulation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cp\u003eCC0-CC1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e55 (41%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cp\u003e14 (58%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c11\" namest=\"c9\"\u003e \u003cp\u003e41 (37%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e\u003cb\u003e0.057\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cp\u003eCC2-CC3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e79 (59.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cp\u003e10 (41.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c11\" namest=\"c9\"\u003e \u003cp\u003e69 (62.7%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e \u003cp\u003eJ-CTO score, median [IQR]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2 [\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cp\u003e3 [\u003cspan additionalcitationids=\"CR3\" citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c11\" namest=\"c9\"\u003e \u003cp\u003e2 [\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e\u003cb\u003e0.006\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"12\" nameend=\"c12\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eCTO\u003c/b\u003e: Chronic total occlusion. \u003cb\u003eRCA\u003c/b\u003e: Right coronary artery. \u003cb\u003eLAD\u003c/b\u003e: Left anterior descending artery. \u003cb\u003eLCx\u003c/b\u003e: Left circumflex artery. \u003cb\u003eLMT\u003c/b\u003e: Left main trunk. \u003cb\u003eCABG\u003c/b\u003e: Coronary artery bypass grafting. \u003cb\u003ePCI\u003c/b\u003e: Percutaneous coronary intervention. \u003cb\u003eMI\u003c/b\u003e: Myocardial infarction. \u003cb\u003eCC\u003c/b\u003e: Werner grading. \u003cb\u003eJ-CTO\u003c/b\u003e: Japanese Chronic Total Occlusion score.\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eProcedural characteristics of the included patients are summarised in Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e. The final crossing wire most frequently belonged to the Fielder, Gaia families, and Gladius wires (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Stent implantation was performed in 97.2% of successful procedures, with a median of 1 stent per lesion [IQR 1\u0026ndash;2] and a median total stent length of 49 mm [IQR 40\u0026ndash;69]. Drug coated balloons were used in 10.9% of successful cases, mainly in combination with stenting.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eProcedural characteristics of the included patients according to technical success\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariable\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCategory / Value\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eOverall (N\u0026thinsp;=\u0026thinsp;134)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eCTO failure (n\u0026thinsp;=\u0026thinsp;24)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eCTO success (n\u0026thinsp;=\u0026thinsp;110)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003ep value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eGuiding catheter size\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6F\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e33 (24.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e6 (25%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e27 (24.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7F\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e94 (70.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e17 (70.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e77 (70%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026ge;\u0026thinsp;7.5F\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7 (5.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1 (4.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e6 (85.7%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eAccess site\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRadial\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e98 (73.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e15 (62.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e83 (75.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.195\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eFemoral\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e36 (26.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e9 (37.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e27 (24.54%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003eDual injection\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e103 (76.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e18 (75%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e85 (77.27%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.811\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eFinal crossing strategy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePrimarily antegrade\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e84 (62.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e11 (45.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e73 (66.36%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.06\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePrimarily retrograde\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9 (6.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2 (8.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e7 (6.36%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.727\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHybrid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e41 (30.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e11 (45.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e30 (27.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.074\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePrevious CTO attempt\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e36 (26.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7 (29.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e29 (26.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.78\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGuide extension catheter\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e13 (9.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3 (12.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e10 (9.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.61\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIVUS use\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e3 (2.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1 (4.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2 (1.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.481\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRotational atherectomy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e5 (3.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0 (0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e5 (4.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.287\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDual-lumen microcatheter\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e4 (3.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1 (4.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3 (2.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.707\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMicrocatheter use\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e113 (84.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e21 (87.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e92 (83.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.765\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTapered guidewire\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e100 (74.62%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e17 (70.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e83 (75.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.64\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal number of guidewires, median [IQR]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e3 [\u003cspan additionalcitationids=\"CR3\" citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4 [\u003cspan additionalcitationids=\"CR4 CR5\" citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3 [\u003cspan additionalcitationids=\"CR3\" citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cb\u003e0.006\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eProcedural time (min) median [IQR]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e120 [83.8\u0026ndash;180]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e150 [120\u0026ndash;227.5]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e120 [75.8\u0026ndash;180]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cb\u003e0.005\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCrossing time (min) median [IQR]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e20 [5\u0026ndash;50]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0 [0\u0026ndash;33.8]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e28.5 [10.8\u0026ndash;54]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFluoroscopy time (min) median [IQR]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e48 [30\u0026ndash;81]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e65.2 [48.7\u0026ndash;110.5]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e41 [28.8\u0026ndash;71.3]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cb\u003e0.006\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eContrast volume (ml) median [IQR]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e180 [150\u0026ndash;200]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e190 [150\u0026ndash;260]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e180 [150\u0026ndash;200]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.228\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAir kerma (mGy) median [IQR]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e1993 [1180\u0026ndash;3085]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2811 [1993\u0026ndash;3628]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1890 [1081\u0026ndash;2872]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cb\u003e0.010\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDose-area product (Gy\u0026middot;cm\u0026sup2;) median [IQR]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e11922 [7106\u0026ndash;20802]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e18323 [10488\u0026ndash;20802]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e11515 [7106\u0026ndash;20223]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.09\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"6\" nameend=\"c6\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eCTO\u003c/b\u003e: Chronic total occlusion. \u003cb\u003eIVUS\u003c/b\u003e: Intravascular ultrasound. \u003cb\u003eGy\u0026middot;cm\u0026sup2;\u003c/b\u003e: Gray\u0026ndash;square centimetre. \u003cb\u003emGy\u003c/b\u003e: Milligray.\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eA primary antegrade strategy was planned in 62.7% of procedures, and a primary retrograde strategy in 6.7%. The final successful crossing strategy remained primary antegrade in 62.7% of cases; however, strategy transition occurred frequently, reflecting implementation of a hybrid approach in 30.6% of cases. Successful antegrade recanalization was achieved in approximately 70% of antegrade attempts, including 50.8% via AWE and 10% via ADR. Among procedures requiring a retrograde approach (n\u0026thinsp;=\u0026thinsp;50), retrograde wire crossing was achieved in 56%, with reverse CART employed in 38% of retrograde attempts. Septal collaterals constituted the predominant retrograde pathway (84%), most commonly CC2 collaterals (62%).\u003c/p\u003e \u003cp\u003eTechnical success was achieved in 110 procedures (82.1%), with TIMI 3 flow restoration in all successful cases. Overall procedural success was 81.3%. The primary mechanism of failure was inability to cross the occlusion with a guidewire (15.7%). Technical success improved significantly over time, increasing from 66.7% in 2022 to 88.8% in 2024 (linear-by-linear association χ\u0026sup2; = 6.40, p\u0026thinsp;=\u0026thinsp;0.011). Periprocedural complications occurred in 19 procedures (14.2%), corresponding to 24 total events, including 6 major complications (4.5%). Haemodynamic instability requiring catecholamine support was the most frequent complication (6.7%). Side-branch occlusion\u0026thinsp;\u0026ge;\u0026thinsp;2.5 mm occurred in 4.5%, stroke in 1.5%, coronary perforation without tamponade in 0.7%, donor artery dissection in 2.2%, and contrast-associated acute kidney injury in 2.2%. In-hospital MACCE occurred in 3 of 114 patients (2.63%). No urgent repeat revascularisation was recorded.\u003c/p\u003e \u003cp\u003eFailed procedures were associated with moderate-to-severe calcification (70.8% vs 31.8%, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), higher J-CTO score (median 3 vs 2, p\u0026thinsp;=\u0026thinsp;0.006), poor collateral circulation (p\u0026thinsp;=\u0026thinsp;0.057), and severely reduced LVEF\u0026thinsp;\u0026le;\u0026thinsp;35% (40.0% vs 18.3%, p\u0026thinsp;=\u0026thinsp;0.010). In multivariable analysis, the clinically relevant independent predictors of technical failure were J-CTO score\u0026thinsp;\u0026ge;\u0026thinsp;3 (OR 4.07, 95% CI 1.53\u0026ndash;10.88, p\u0026thinsp;=\u0026thinsp;0.005) and LVEF\u0026thinsp;\u0026le;\u0026thinsp;35% (OR 3.90, 95% CI 1.38\u0026ndash;11.04, p\u0026thinsp;=\u0026thinsp;0.010).\u003c/p\u003e \u003cp\u003eFollow-up was available for 73% of patients at twelve months. Median follow-up duration was 22 months [IQR 11\u0026ndash;35]. MACCE occurred in 15 patients (13.2%), including 7 deaths and 8 myocardial infarctions. All-cause mortality was 6.1%. Kaplan\u0026ndash;Meier analysis showed a twelve-month MACCE-free survival of 86.3% (95% CI 79.8\u0026ndash;92.8%). MACCE incidence was significantly higher in patients with technical failure (60% vs 8.7%, log-rank p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Reduced LVEF (\u0026le;\u0026thinsp;35%) was associated with lower MACCE-free survival (log-rank p\u0026thinsp;=\u0026thinsp;0.038). Target lesion failure occurred in 3 patients (2.6%), with a twelve-month TLF-free survival of 97.1% (95% CI 93.8\u0026ndash;100.0%). No significant differences were observed according to LVEF category or technical success.\u003c/p\u003e \u003cp\u003eAmong symptomatic patients with paired follow-up data, significant improvement in angina severity was observed at twelve months. CCS class improved in 66 patients (81.5%) (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), and NYHA functional class improved in 42 patients (51.9%) (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). At twelve months, patients with successful CTO-PCI had significantly lower CCS class (median 1.0 vs 3.0, p\u0026thinsp;=\u0026thinsp;0.013) and NYHA class (median 1.0 vs 2.0, p\u0026thinsp;=\u0026thinsp;0.011) compared with those with technical failure.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis prospective single-centre study describes the early evolution of a CTO-PCI programme in a North African low- to middle-income centre. Across 134 procedures, technical success reached 82.1% and improved significantly over time, approaching 90% in the final year, consistent with a learning-curve effect. Lesion complexity (J-CTO\u0026thinsp;\u0026ge;\u0026thinsp;3) and severely reduced left ventricular ejection fraction (LVEF\u0026thinsp;\u0026le;\u0026thinsp;35%) independently predicted technical failure. Periprocedural complication rates were acceptable, and twelve-month MACCE-free survival and symptomatic improvement were substantial. These findings demonstrate that structured CTO-PCI programmes can achieve registry-comparable outcomes in emerging centres despite intermediate-to-high anatomical complexity.\u003c/p\u003e \u003cp\u003eCompared with contemporary international CTO registries, the Farhat Hached cohort reflects a higher-risk clinical profile despite broadly comparable demographic characteristics. Mean age (60.9\u0026thinsp;\u0026plusmn;\u0026thinsp;9.1 years) was similar to that reported in MENATA (\u0026asymp;\u0026thinsp;61 years) and PROGRESS-CTO cohorts (\u0026asymp;\u0026thinsp;65years) [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Male predominance (84.2%) was also consistent with global CTO populations, where male representation typically exceeds 80% [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eHowever, the burden of cardiovascular risk factors was notable. Diabetes mellitus was present in 60.5% of patients\u0026mdash;substantially higher than rates reported in many Western registries (typically 35\u0026ndash;45%) and slightly higher than MENATA [\u003cspan additionalcitationids=\"CR14\" citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. Smoking prevalence (72.8%) was likewise elevated compared with European datasets [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. These findings likely reflect regional epidemiology and may contribute to greater diffuse coronary disease and calcification burden.\u003c/p\u003e \u003cp\u003eA history of prior myocardial infarction (60.5%) and prior PCI (57.0%) mirrored rates reported in expert registries, reflecting established coronary disease and prior revascularisation exposure. In contrast, prior coronary artery bypass grafting was uncommon (5.3%), similar to contemporary datasets [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]\u003c/p\u003e \u003cp\u003eMean LVEF (43.9%) was lower than typically described in selected randomised CTO trials and cohorts. Severe LV dysfunction (LVEF\u0026thinsp;\u0026le;\u0026thinsp;35%) was present in 20.2% of patients, markedly higher than proportions reported in ERCTO (7.6%) and OPEN-CTO (13.7%), suggesting inclusion of a more clinically vulnerable population [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eRegarding clinical presentation, stable angina predominated (76.3%), consistent with elective CTO practice in OPEN-CTO, PROGRESS-CTO, and MENATA cohorts [\u003cspan additionalcitationids=\"CR14\" citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Importantly, angina severity was substantial at baseline, with 78.2% classified as CCS III\u0026ndash;IV, representing a higher symptomatic burden than reported in OPEN-CTO (72.4%) and PROGRESS-CTO (63.6%). These features position the cohort as clinically higher-risk compared with many Western series and provide essential context for interpreting procedural success and mid-term outcomes.\u003c/p\u003e \u003cp\u003eFrom an angiographic perspective, target vessels\u0026rsquo; distribution differed from several international datasets. Whereas OPEN-CTO, PROGRESS-CTO, EURO-CTO, and MENATA registries reported right coronary artery predominance (55\u0026ndash;64%), the Farhat Hached cohort demonstrated a higher proportion of left anterior descending (LAD) CTOs (47%). This distinction is clinically relevant, as LAD CTOs subtend a larger myocardial territory and may carry greater prognostic implications [\u003cspan additionalcitationids=\"CR14 CR15\" citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Median J-CTO score was 2 (IQR 1\u0026ndash;3), indicating intermediate lesion complexity, comparable to MENATA (\u0026asymp;\u0026thinsp;2.1) and PROGRESS-CTO (2.43\u0026thinsp;\u0026plusmn;\u0026thinsp;1.30), and higher than that observed in the EURO-CTO PCI arm (1.82\u0026thinsp;\u0026plusmn;\u0026thinsp;1.07), reflecting the inclusion of a less selected and anatomically more complex cohort [\u003cspan additionalcitationids=\"CR14 CR15\" citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Lesion length (median 25 mm) was slightly shorter than MENATA (\u0026asymp;\u0026thinsp;30 mm), although moderate-to-severe calcification was observed in 38.8% of lesions, exceeding rates in several western and regional registries and suggesting a greater burden of advanced atherosclerosis [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. Bifurcation involvement (47.8%) was also frequent and higher than reported in ERCTO, reinforcing anatomical complexity [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. Collateral patterns were broadly comparable to international experience, with CC2\u0026ndash;3 collaterals present in approximately 59% of cases, similar to PROGRESS-CTO (56.7%) but lower than ERCTO (89.7%) [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. In-stent CTO prevalence (11.9%) was lower than in some international cohorts, suggesting predominance of de novo occlusions [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. Overall, the angiographic profile aligns with contemporary real-world CTO practice and supports interpretation of procedural success within an appropriate anatomical framework.\u003c/p\u003e \u003cp\u003eRadial access predominated in the Farhat Hached cohort (73.1%), exceeding rates reported in major CTO registries and reflecting strong radial proficiency even in complex lesions [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. Dual arterial injection was frequently employed (76.9%), consistent with contemporary European practice and supporting optimal lesion visualisation [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. An antegrade-first strategy remained dominant (\u0026asymp;\u0026thinsp;63%), while retrograde techniques were used in over one-third of procedures, aligning with modern hybrid practice patterns. Hybrid strategy adoption (30.6%) demonstrates adherence to contemporary CTO algorithms and likely contributed to the progressive improvement in technical success observed over time.\u003c/p\u003e \u003cp\u003eTechnical success (82.1%) aligns with contemporary real-world CTO registries, though slightly lower than large expert cohorts such as PROGRESS-CTO (\u0026asymp;\u0026thinsp;87%) and the Japanese CTO-PCI Expert Registry (\u0026asymp;\u0026thinsp;92%) [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. Compared with MENATA (\u0026asymp;\u0026thinsp;91%), the modest difference may reflect multicentre expert participation and broader access to intravascular imaging [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Nevertheless, lesion complexity was comparable across cohorts, supporting the feasibility of CTO-PCI in a North African middle-income setting.\u003c/p\u003e \u003cp\u003eHigh lesion complexity (J-CTO\u0026thinsp;\u0026ge;\u0026thinsp;3) independently predicted technical failure (OR 4.07), aligning with PROGRESS-CTO findings showing a two-fold increase in failure per point increase in J-CTO score and supported by meta-analytic data validating its strong predictive value for procedural difficulty. [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. Severely reduced left ventricular function (LVEF\u0026thinsp;\u0026le;\u0026thinsp;35%) also independently predicted failure (OR 3.90). Although expert registries report similar technical success across LVEF strata, patients with impaired ventricular function consistently exhibit higher clinical risk [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. The higher prevalence of severe systolic dysfunction in the Farhat Hached cohort, combined with limited access to routine mechanical circulatory support, may explain its procedural impact in this setting. Thus, in middle-income centres, ventricular dysfunction may exert a more tangible influence on technical outcome than in high-volume expert institutions\u003c/p\u003e \u003cp\u003eIn-hospital MACCE (2.6%) falls within the 1.7\u0026ndash;3% range reported in PROGRESS-CTO and ERCTO registries [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. Although overall periprocedural complications were numerically higher (14.2%), this reflects comprehensive event capture, whereas registry definitions vary. Major complications (4.5%) remain within contemporary real-world ranges (3\u0026ndash;10%) [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e, \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. Thus, procedural safety was comparable to international standards despite intermediate-to-high lesion complexity and limited intravascular imaging utilisation.\u003c/p\u003e \u003cp\u003eAt twelve months, MACCE occurred in 13.2% of patients. This rate is comparable to mid-term event rates reported in OPEN-CTO (\u0026asymp;\u0026thinsp;10%) and other all-comer registries, though higher than the 5.2% reported in the EURO-CTO PCI arm, which included more selected populations [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Kaplan\u0026ndash;Meier analysis demonstrated significantly lower event rates among patients with successful recanalization, mirroring findings from PROGRESS-CTO, where lower MACE rates were observed following successful CTO recanalization compared with technical failure [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. These findings reinforce the clinically meaningful association between technical success and improved mid-term outcomes. Target lesion failure (2.6%) was consistent with contemporary drug-eluting stent performance and comparable to TLR/TLF rates reported in EURO-CTO and RECHARGE registries [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e, \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eSymptomatic improvement was substantial and clearly success-dependent, with 81.5% of patients demonstrating CCS improvement at twelve months. This parallels the EURO-CTO randomised trial, which showed significant angina reduction and improved quality of life following CTO-PCI compared with optimal medical therapy [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Although symptom assessment in EURO-CTO relied on validated patient-reported instruments rather than CCS or NYHA classification, the overall pattern of benefit closely mirrors the present findings. Further concordance is seen in the UK hybrid CTO experience reported by Wilson et al., where 88% of successfully treated patients were free of angina or minimally symptomatic at twelve months [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. Unlike the MENATA regional dataset, our study incorporated structured CCS and NYHA follow-up, providing patient-centred outcome data beyond angiographic success [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eWithin the national context, the Farhat Hached cohort demonstrated higher rates of severe LV dysfunction and greater lesion complexity compared with La Rabta and Habib Thameur CTO cohorts. Despite this, technical success was numerically higher (82.1% vs 79.3% and 69.2%). Greater adoption of dual access, microcatheters, and hybrid escalation strategies likely contributed to these differences. Importantly, Farhat Hached is the only Tunisian cohort to provide systematic twelve-month MACCE and symptom follow-up, enabling assessment of sustained clinical benefit beyond procedural metrics [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eData on CTO-PCI from North Africa remain scarce. This study provides prospective real-world evidence demonstrating that structured hybrid CTO-PCI can achieve registry-level safety and efficacy in a low- to middle-income healthcare setting. Despite inclusion of higher-risk patients and resource constraints, outcomes approached those of established international registries, supporting expansion of contemporary CTO programmes in similar environments.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eIn this prospective single-centre study, implementation of a contemporary hybrid CTO-PCI programme in a North African low- to middle-income centre achieved technical success rates comparable to major international registries despite a clinically higher-risk population with elevated diabetes prevalence, substantial symptomatic burden, and frequent severe left ventricular dysfunction. Technical success improved significantly over time, approaching 90% in the final year, reflecting operator experience and structured adoption of hybrid strategies. Lesion complexity (J-CTO\u0026thinsp;\u0026ge;\u0026thinsp;3) independently predicted technical failure, consistent with global data, while severely reduced LVEF also emerged as an independent determinant, suggesting that ventricular dysfunction may exert greater procedural impact in resource-constrained settings. Procedural safety was acceptable, with in-hospital MACCE within contemporary registry ranges and low twelve-month target lesion failure. Successful recanalization was strongly associated with improved mid-term outcomes and marked symptomatic relief, reinforcing the clinical value of CTO-PCI beyond angiographic endpoints. These findings support the feasibility and scalability of modern CTO programmes in similar healthcare environments and contribute meaningful prospective data from an underrepresented region.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003e\u003cstrong\u003e\u003cem\u003eCTO:\u003c/em\u003e\u003c/strong\u003e Chronic total occlusion \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003ePCI:\u003c/em\u003e\u003c/strong\u003e Percutaneous coronary intervention \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eCTO-PCI:\u003c/em\u003e\u003c/strong\u003e Chronic total occlusion percutaneous coronary intervention \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eTIMI:\u003c/em\u003e\u003c/strong\u003e Thrombolysis in Myocardial Infarction \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eMACCE:\u003c/em\u003e\u003c/strong\u003e Major adverse cardiac and cerebrovascular events \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eTLF:\u003c/em\u003e\u003c/strong\u003e Target lesion failure \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eLVEF:\u003c/em\u003e\u003c/strong\u003e Left ventricular ejection fraction \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eCCS:\u003c/em\u003e\u003c/strong\u003e Canadian Cardiovascular Society \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eNYHA:\u003c/em\u003e\u003c/strong\u003e New York Heart Association \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eJ-CTO:\u003c/em\u003e\u003c/strong\u003e Japanese Chronic Total Occlusion score \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eIVUS:\u003c/em\u003e\u003c/strong\u003e Intravascular ultrasound \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eADR:\u003c/em\u003e\u003c/strong\u003e Antegrade dissection and re-entry \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eAWE:\u003c/em\u003e\u003c/strong\u003e Antegrade wire escalation \u0026nbsp;\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe data used in this study can be obtained from corresponding author, Ben Abdessalem Mohamed Aymen ([email protected]) upon reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors thank the medical and nursing staff of the Cardiology Department of Farhat Hached University Hospital for their contribution to patient care.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was not supported by any sponsor or funder.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor information\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eDepartment of Cardiology, Farhat Hached University Hospital, Sousse, Tunisia.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eContributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eM.A.B.A. and J.B conceived the study, collected data, performed analysis, and drafted the manuscript. Z.B.A., H.F., M.Y., and A.M. contributed to data collection, interpretation, and manuscript revision. \u0026nbsp; All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCorresponding author\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eCorrespondence to Mohamed Aymen Ben Abdessalem.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNo funding was provided during this observational prospective study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics statement :\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis prospective observational study was approved by the Research Ethics Committee of Farhat Hached University Hospital and the Faculty of Medicine of Sousse. Written informed consent was obtained from all participants. The study was conducted in accordance with the principles of the Declaration of Helsinki.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication :\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests :\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDisclosure of interest :\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors report no conflicts of interest.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eYbarra LF, Rinfret S, Brilakis ES, Karmpaliotis D, Azzalini L, Grantham JA, et al. Definitions and Clinical Trial Design Principles for Coronary Artery Chronic Total Occlusion Therapies: CTO-ARC Consensus Recommendations. 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Intermediate procedural and health status outcomes and the clinical care pathways after chronic total occlusion angioplasty: A report from the OPEN‐CTO (outcomes, patient health status, and efficiency in chronic total occlusion hybrid procedures) study. Catheter Cardiovasc Interv. 2020 Oct 27;ccd.29343. doi:10.1002/ccd.29343\u003c/li\u003e\n\u003cli\u003eSimsek B, Kostantinis S, Karacsonyi J, Alaswad K, Krestyaninov O, Khelimskii D, et al. Predicting Periprocedural Complications in Chronic Total Occlusion Percutaneous Coronary Intervention. JACC: Cardiovascular Interventions. 2022 Jul;15(14):1413\u0026ndash;22. doi:10.1016/j.jcin.2022.06.007\u003c/li\u003e\n\u003cli\u003eSimsek B, Kostantinis S, Karacsonyi J, Brilakis ES. Scores for Chronic Total Occlusion Percutaneous Coronary Intervention: A Window to the Future? J Am Heart Assoc. 2022 May 16;11(10):e026070. doi:10.1161/JAHA.122.026070 PubMed PMID: 35574966; PubMed Central PMCID: PMC9238564.\u003c/li\u003e\n\u003cli\u003eXenogiannis I, Karmpaliotis D, Krestyaninov O, Khelimskii D, Khatri J, Alaswad K, et al. FOLLOW-UP OUTCOMES AFTER CHRONIC TOTAL OCCLUSION PERCUTANEOUS CORONARY INTERVENTION: DOES SUCCESSFUL REVASCULARIZATION MATTER ? Journal of the American College of Cardiology. 2020 Mar;75(11):1296. doi:10.1016/S0735-1097(20)31923-9\u003c/li\u003e\n\u003cli\u003eMaeremans J, Walsh S, Knaapen P, Spratt JC, Avran A, Hanratty CG, et al. The Hybrid Algorithm for Treating Chronic Total Occlusions in Europe. Journal of the American College of Cardiology. 2016 Nov;68(18):1958\u0026ndash;70. doi:10.1016/j.jacc.2016.08.034\u003c/li\u003e\n\u003cli\u003eWilson WM, Walsh SJ, Bagnall A, Yan AT, Hanratty CG, Egred M, et al. One‐year outcomes after successful chronic total occlusion percutaneous coronary intervention: The impact of dissection re‐entry techniques. Cathet Cardio Intervent. 2017 Nov;90(5):703\u0026ndash;12. doi:10.1002/ccd.26980\u003c/li\u003e\n\u003cli\u003eBADER M. Percutaneous Coronary Intervention of Coronary Chronic Total Occlusion: In-Hospital and Long-Term Outcomes. [Tunis, Tunisia]: Tunis El Manar University \u0026ndash; Faculty of Medicine of Tunis; 2024.\u003c/li\u003e\n\u003cli\u003eLamine H, Bouzidi H, Hammami S, Saidane S, Iddir S, Kraiem S. Angioplastie des occlusions totales chroniques : Rapport de cinq ans d\u0026rsquo;exp\u0026eacute;rience dans un centre Tunisien multi-op\u0026eacute;rateurs. Tunis Med. 2025 Jan;103(1):142\u0026ndash;51. doi:10.62438/tunismed.v103i1.4940 PubMed PMID: 39812208; PubMed Central PMCID: PMC11906239.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-cardiovascular-disorders","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bcar","sideBox":"Learn more about [BMC Cardiovascular Disorders](http://bmccardiovascdisord.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bcar/default.aspx","title":"BMC Cardiovascular Disorders","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Chronic Total Occlusion, Percutaneous Coronary Intervention,Angina, Prognosis","lastPublishedDoi":"10.21203/rs.3.rs-9113443/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9113443/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground:\u003c/strong\u003e Evidence on chronic total occlusion percutaneous coronary intervention (CTO-PCI) from North Africa remains scarce, with limited data on procedural outcomes and patient-centred endpoints in resource-constrained settings.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods:\u003c/strong\u003e Prospective single-centre study of 114 patients undergoing 134 CTO-PCI procedures (2022-2024) at Farhat Hached University Hospital, Tunisia. CTOs were treated using contemporary hybrid algorithms. Technical success required TIMI 3 flow with \u0026lt;30% residual stenosis. Primary endpoint: immediate outcomes and technical success predictors. Secondary endpoints: 12-month major adverse cardiac/cerebrovascular events (MACCE), target lesion failure (TLF), and symptom improvement (CCS/NYHA class). Multivariable logistic regression identified technical failure predictors.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults:\u003c/strong\u003e Mean age was 60.9±9.1 years; 84.2% male. High-risk features included diabetes (60.5%), smoking (72.8%), and severe LVEF≤35% (20.2%). Median J-CTO score was 2 (IQR 1-3). Technical success was 82.1%, improving from 66.7% (2022) to 88.8% (2024; p=0.011). Independent technical failure predictors were J-CTO≥3 (OR 4.07, 95%CI 1.53-10.88) and LVEF≤35% (OR 3.90, 95%CI 1.38-11.04). In-hospital MACCE was 2.6%; periprocedural complications 14.2% (major: 4.5%). At 12 months, MACCE was 13.2% (86.3% MACCE-free survival); TLF 2.6%. Successful CTO-PCI predicted lower MACCE (8.7% vs 60%, p\u0026lt;0.001) and superior symptomatic improvement at 12 months, with marked reductions in CCS and NYHA class compared with technical failure (p=0.013 and p=0.011, respectively).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions:\u003c/strong\u003e Structured hybrid CTO-PCI in a North African centre achieved registry-comparable technical success (82.1%) and safety despite higher-risk patients and resource limits. Success strongly associated with mid-term event reduction and substantial symptom improvement, supporting scalability of modern CTO programs in emerging economies.\u003c/p\u003e","manuscriptTitle":"Hybrid algorithm CTO-PCI in a Resource-Constrained Tunisian Center","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-23 15:01:39","doi":"10.21203/rs.3.rs-9113443/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"editorInvitedReview","content":"","date":"2026-05-03T17:09:07+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"245557521139520073772511761482654764931","date":"2026-04-27T11:29:02+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"250583536570209752000066548779576690958","date":"2026-04-27T08:50:23+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-25T21:36:38+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"159299638925490713713313738769146319596","date":"2026-04-23T20:30:41+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-22T11:24:22+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"22910025381670254623469002360617427170","date":"2026-04-22T11:05:24+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"32942205542923767368738635678764687871","date":"2026-04-21T20:43:48+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-16T08:03:49+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"297090880252518003082948784620624226740","date":"2026-04-15T11:45:41+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"262246231711662234699859914536031723207","date":"2026-04-15T11:06:51+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-04-15T10:22:57+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-04-13T07:02:50+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2026-03-25T19:05:51+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-03-23T15:15:23+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Cardiovascular Disorders","date":"2026-03-23T12:31:27+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-cardiovascular-disorders","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bcar","sideBox":"Learn more about [BMC Cardiovascular Disorders](http://bmccardiovascdisord.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bcar/default.aspx","title":"BMC Cardiovascular Disorders","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"385985fb-6823-420b-99d6-00a491c357de","owner":[],"postedDate":"April 23rd, 2026","published":true,"recentEditorialEvents":[{"type":"editorInvitedReview","content":"","date":"2026-05-03T17:09:07+00:00","index":66,"fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-04-23T15:01:40+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-23 15:01:39","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9113443","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9113443","identity":"rs-9113443","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}