Exploratory Phase Angle Assessment After Atrial Fibrillation Ablation in Overweight Patients: A Pilot Study

Exploratory Phase Angle Assessment After Atrial Fibrillation Ablation in Overweight Patients: A Pilot Study | 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 Exploratory Phase Angle Assessment After Atrial Fibrillation Ablation in Overweight Patients: A Pilot Study Sang-Suk Choi, Kyunyeon Kim, Sung Jung Kim, YouMi Hwang This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7631336/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 13 Feb, 2026 Read the published version in BMC Cardiovascular Disorders → Version 1 posted 11 You are reading this latest preprint version Abstract Background The phase angle (PhA), derived from bioelectrical impedance analysis (BIA), is an indicator of cellular health and nutritional status. Its role in patients with atrial fibrillation (AF), particularly after catheter ablation, is not well-established. This study aimed to investigate changes in PhA and their correlation with cardiac remodeling in overweight patients with persistent AF after cryoballoon ablation. Methods Thirteen overweight patients (BMI ≥ 23 kg/m²) with persistent AF scheduled for ablation were prospectively enrolled. Baseline clinical, echocardiographic, and BIA parameters were collected. At 6 months, follow-up data were available for 12 patients. AF recurrence was defined as any atrial tachyarrhythmia ≥ 30 seconds beyond a 3-month blanking period, confirmed by ECG or Holter monitoring. Results Five patients experienced AF recurrence (PEF group), while eight maintained sinus rhythm (NSR group). Overall, no significant changes were observed in the total cohort. However, subgroup analysis demonstrated divergent changes in body composition. The NSR group showed significant improvements in intracellular water and phase angle values, whereas the PEF group exhibited consistent declines (p < 0.05 for group comparisons). Conclusion These preliminary findings suggest that successful rhythm control after ablation may be associated with systemic recovery reflected by BIA-derived parameters. Larger, multicenter studies incorporating functional and clinical outcomes are warranted to validate the potential role of PhA as a biomarker for post-ablation recovery. Trial registration: not applicable Atrial Fibrillation Catheter Ablation Bioelectrical Impedance Analysis Phase Angle Overweight 1. Background Atrial fibrillation (AF) is the most common arrhythmia, increasing with age, and its prevalence is projected to grow substantially [ 1 ]. It is associated with significant morbidity, including stroke and heart failure, thereby impairing quality of life [ 2 ]. The pathophysiology of AF involves profound hemodynamic consequences; the loss of coordinated atrial contraction and an irregular ventricular response can reduce cardiac output, leading to systemic hypoperfusion and neurohormonal activation [ 3 ]. These changes promote fluid retention, a key feature in AF-related heart failure. Beyond its direct arrhythmogenic effects, AF is increasingly recognized as a systemic condition associated with chronic inflammation and neurohormonal activation [ 4 ]. These processes contribute to adverse body composition changes, such as sarcopenia and cardiac cachexia, which are potent independent predictors of poor outcomes in AF patients [ 5 , 6 ]. Furthermore, obesity is a well-established risk factor for the development and progression of AF and is associated with lower success rates after catheter ablation [ 7 ]. The underlying mechanisms are complex, involving structural changes like left atrial enlargement, epicardial adipose tissue, and systemic inflammation [ 8 ]. Given this intricate relationship, understanding how rhythm control impacts body composition, particularly in overweight individuals, is of significant clinical importance. This highlights the need for tools that can assess the systemic burden of AF beyond traditional cardiac metrics. Bioelectrical Impedance Analysis (BIA) is a validated, non-invasive method for assessing body composition and fluid status in patients with cardiac conditions [ 9 , 10 ]. While parameters such as the ratio of extracellular to total body water (ECW/TBW) can be used to quantify fluid overload [ 11 ], the phase angle (PhA) has emerged as a particularly valuable metric for this purpose. The PhA is a robust indicator of cellular health and membrane integrity [ 12 ]. A lower PhA reflects compromised cell membranes and is a powerful predictor of mortality in chronic diseases, particularly heart failure [ 13 , 14 ]. It is considered an objective measure of systemic health, integrating information on fluid balance, nutritional status, and inflammation [ 15 ]. While rhythm control strategies for AF aim to improve cardiac function, their impact on systemic cellular integrity has not been fully elucidated. This is the first preliminary study to comprehensively evaluate changes in body water composition and phase angle in overweight patients with atrial fibrillation following cryoablation. 2. Methods 2.1 Study Population and Design This prospective, single-center, observational pilot study was approved by the Institutional Review Board of St. Vincent’s Hospital, The Catholic University of Korea (IRB No. VC24OISI0017), and all participants provided written informed consent. The study was conducted in accordance with the principles of the Declaration of Helsinki. We enrolled 13 patients diagnosed with persistent atrial fibrillation who were scheduled for rhythm control therapy. The inclusion criteria were: 1) age ≥ 20 years, and 2) overweight, defined as a Body Mass Index (BMI) ≥ 23 kg/m². Baseline characteristics, echocardiographic data, and BIA parameters were collected before the procedure. All patients underwent follow-up assessments, including BIA and echocardiography, after 6 months (± 1 month) after the ablation. One patient was excluded from the follow-up analysis due to the aggravation of sick sinus syndrome requiring permanent pacemaker implantation after the procedure. Consequently, the final analysis of post-ablation changes was performed on 12 patients. The primary outcome was the change in phase angle from baseline to 6 months, stratified by rhythm outcome. Secondary outcomes included changes in intracellular water (ICW), total body water (TBW), extracellular water (ECW), and echocardiographic parameters such as LVEF, LAVI, and E/e’. AF recurrence was defined as any episode of atrial tachyarrhythmia lasting ≥ 30 seconds, confirmed by 12-lead ECG, 24-hour Holter monitoring, or event recorder, beyond a 3-month blanking period. All patients underwent a scheduled ECG at each follow-up outpatient clinic visit, and a symptom-triggered ECG or Holter monitor was performed when clinically indicated. 2.2 Procedure 2.2.1 Cryoablation All procedures were performed in fasting patients under conscious sedation, which was maintained with a continuous infusion of remifentanil. Following local anesthesia with 1% lidocaine, percutaneous vascular access was obtained from the right and left femoral veins. A 5Fr diagnostic catheter (typically quadripolar or decapolar) was positioned in the superior vena cava (SVC) for pacing and monitoring. A single transseptal puncture was performed under fluoroscopic and hemodynamic guidance to access the left atrium. In one of the nine cases, intracardiac echocardiography (ICE) was also utilized for guidance. An 8.5Fr SL1 sheath was used for the puncture and subsequently exchanged for a 15Fr steerable sheath (FlexCath Advance™, Medtronic, Minneapolis, MN, USA). A 28 mm second-generation cryoballoon catheter (Arctic Front Advance Pro™, Medtronic) and an integrated circular mapping catheter (Achieve™, Medtronic) were then advanced into the left atrium. The procedure consisted of the complete electrical isolation of all four pulmonary veins (PVs). The target ablation temperature was typically between − 40°C and − 60°C. During ablation of the right-sided PVs, the phrenic nerve was continuously monitored by high-output pacing from the catheter in the SVC to prevent phrenic nerve injury. After successful pulmonary vein isolation, patients underwent synchronized direct current cardioversion (DCCV) under deep sedation with intravenous etomidate to restore sinus rhythm. The procedure was completed without any immediate complications. 2.3 Data Collection Clinical, echocardiographic, and bioelectrical impedance analysis (BIA) data were collected at baseline and the 6-month follow-up visit. Clinical data included demographics, comorbidities, and medications. Blood samples were collected for serum creatinine and N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels. At baseline, cardiac computed tomography (CT) was also performed to measure the left atrial (LA) diastolic volume, excluding the appendage. Transthoracic echocardiography was performed to assess left ventricular ejection fraction (LVEF), left atrial volume index (LAVI), E/e', and right ventricular systolic pressure (RVSP). Body composition was measured using a multi-frequency BIA device (InBody BWA2.0, InBody Co., Ltd, Seoul, Korea). Patients were instructed to fast for at least 4 hours before the measurement. All measurements were taken in a standing position, with electrodes attached to the hands and feet according to the manufacturer's protocol. Baseline computed tomography left atrial volume (CT LAV) data were missing for one patient in the PEF group and were thus excluded from the relevant analyses. 2.4 Statistical Analysis As this was a preliminary study with a small sample size, non-parametric tests were employed for statistical analysis. Data are presented as median (interquartile range) for continuous variables and n (%) for categorical variables. To compare baseline characteristics between the two groups, the Mann-Whitney U test was used for continuous variables, and Fisher's exact test was used for categorical variables. Changes in parameters from baseline to follow-up were also analyzed between the groups using the Mann-Whitney U test. A p-value of less than 0.05 was considered statistically significant. All analyses were performed using R statistical software (version 4.2.3; R Foundation for Statistical Computing, Vienna, Austria). 3. Results 3.1 Baseline Characteristics The baseline characteristics of the 13 enrolled patients are summarized in Table 1 . The median age of the total cohort was 60.0 years (IQR 58.0–66.0), and 11 patients (84.6%) were male. The median BMI was 27.7 kg/m² (IQR 25.7–30.0). At the 6-month follow-up, five patients were assigned to the PEF group (AF recurrence) and 8 to the NSR group (sinus rhythm maintained). When comparing the two groups at baseline, no statistically significant differences were found in clinical demographics or comorbidities. The median age was 61.0 years (IQR, 58.0–67.0) in the PEF group and 59.5 years (IQR, 54.8–64.8) in the NSR group (p = 0.585). BMI was also similar between the groups (PEF: 25.5 kg/m² [IQR 24.7–26.8] vs. NSR: 28.4 kg/m² [IQR 24.9–29.8]; p = 0.222). Echocardiographic parameters, including LVEF (PEF: 56.3% [IQR 50.9–63.9] vs. NSR: 57.9% [IQR 57.1–64.2]; p = 0.643) and LAVI (PEF: 50.3 mL/m² [IQR 39.5–81.8] vs. NSR: 40.5 mL/m² [IQR 31.7–44.1]; p = 0.176), did not differ significantly. All baseline BIA parameters were also comparable between the two groups, whole-body phase angle was 7.0 (IQR 6.1–7.3) in the PEF group and 6.4 (IQR 5.5–7.1) in the NSR group (p = 0.251), and the ECW/TBW ratio was 0.382 (IQR 0.381–0.395) in the PEF group versus 0.388 (IQR 0.372–0.389) in the NSR group (p = 0.643). Table 1 Baseline Characteristics (n = 13) Total (n = 13) Final Rhythm PEF (n = 5) NSR (n = 8) P-value Age, years 60.00 (58.00–66.00) 61.0 (58.0–67.0) 59.5 (54.8–64.8) 0.585 Sex, male 11 (84.6%) 4 (80.0%) 7 (87.5%) 1 Weight, kg 81.10 (72.40–91.90) 72.4 (64.8–77.5) 83.0 (66.7–90.4) 0.312 BMI, kg/m² 27.74 (25.65–30.04) 25.5 (24.7–26.8) 28.4 (24.9–29.8) 0.222 Hypertension 9 (69.2%) 4 (80.0%) 5 (62.5%) 1 Diabetes mellitus 5 (38.5%) 3 (60.0%) 2 (25.0%) 0.282 Dyslipidemia 9 (69.2%) 4 (80.0%) 5 (62.5%) 1 COPD 0 (0.0%) 0 (0.0%) 0 (0.0%) 1 CKD 1 (7.7%) 1 (20.0%) 0 (0.0%) 0.417 E/e' 7.96 (6.61–9.50) 7.4 (7.0-19.9) 7.9 (6.1–8.5) 0.812 LVEF, % 57.90 (56.30–62.50) 56.3 (50.9–63.9) 57.9 (57.1–64.2) 0.643 LAVI, mL/m² 40.50 (37.60–50.30) 50.3 (39.5–81.8) 40.5 (31.7–44.1) 0.176 LAV, mL 81.90 (62.60–93.50) 93.5 (78.9-152.1) 81.9 (62.2–87.2) 0.141 RVSP, mmHg 27.60 (25.60–35.90) 38.0 (27.9–45.5) 27.6 (25.3–35.6) 0.199 CT LAV, mL* 230.11 (213.91-280.93) 215.0 (193.3–228.0) 207.2 (172.9-224.6) 1 Creatinine, mg/dL 1.00 (0.90–1.10) 1.1 (0.9–2.6) 1.0 (0.8–1.2) 0.251 NT-proBNP, pg/mL 414.00 (266.00-631.00) 644.0 (318.0-2603.0) 379.0 (143.0-414.0) 0.141 Total Body Water, L 42.90 (39.60–45.10) 43.9 (37.2–44.2) 43.0 (38.8–48.4) 0.812 ICW, L 26.50 (24.30–28.50) 26.5 (22.5–27.1) 27.8 (23.9–29.0) 0.812 ECW, L 16.60 (15.00-17.30) 17.3 (14.7–17.4) 16.6 (14.9–19.2) 1 ECW/TBW 0.38 (0.38–0.39) 0.382 (0.381–0.395) 0.388 (0.372–0.389) 0.643 Phase Angle 6.60 (6.20–7.30) 7.0 (6.1–7.3) 6.4 (5.5–7.1) 0.251 Phase Angle T-score -1.10 (-2.20-0.00) -0.9 (-1.2 to -0.6) -1.0 (-2.0 to -0.5) 0.812 Phase Angle Z-score 0.20 (-1.00-0.30) 0.2 (-0.9 to 0.3) 0.1 (-1.1 to 0.4) 1 3.2 Changes in Body Composition and Echocardiographic Parameters The changes in parameters for the 12 patients who completed follow-up are presented in Table 2 . When analyzed as a single cohort, there were no statistically significant changes from baseline to follow-up in any of the parameters. However, the subgroup analysis based on rhythm outcome revealed substantial changes, particularly in the BIA parameters. Changes in body weight (PEF: -3.60 kg vs. NSR: -0.40 kg; p = 0.625) and BMI (PEF: -1.27 kg/m² vs. NSR: -0.13 kg/m²; p = 0.639) were not significantly different between the groups. Similarly, changes in echocardiographic parameters such as LVEF (PEF: -1.10% vs. NSR: +1.00%; p = 0.343), LAVI (PEF: +1.2 mL/m² vs. NSR: +0.8 mL/m²; p = 1.00), and E/e' (PEF: -0.48 vs. NSR: +0.88; p = 1.000) did not show significant differences. However, the change in Intracellular Water (ICW) was significantly different, showing a median decrease of -0.60 L (IQR − 1.40 to -0.50) in the PEF group versus a median increase of 0.30 L (IQR − 0.25 to 0.95) in the NSR group (p = 0.048). Furthermore, the change in the phase angle was also significantly different. The PEF group showed a median decrease of -0.20 (IQR − 0.30 to -0.10), whereas the NSR group showed a significant median increase of 0.50 (IQR 0.25 to 0.70) (p = 0.03). This significant opposing trend was consistent across all phase angle-related variables. The changes in the Phase Angle T-score (PEF: -0.20 vs. NSR: +0.70; p = 0.03) and Z-score (PEF: -0.20 vs. NSR: +0.80; p = 0.03) were also significantly different between the two groups. In contrast, other BIA variables, including Total Body Water (PEF: -0.50 L vs. NSR: +0.60 L; p = 0.073), Extracellular Water (PEF: +0.20 L vs. NSR: +0.50 L; p = 0.343), and the ECW/TBW ratio (PEF: +0.01 vs. NSR: 0.00; p = 0.086), did not show statistically significant differences between the groups. Table 2 Comparison of Changes in Parameters at 6-Month Follow-up, Stratified by Rhythm Outcome (n = 12) Total (n = 12) P-value Final Rhythm PEF (n = 5) NSR (n = 8) P-value Weight, kg -0.80 (-5.03-1.17) 0.176 -3.60 (-4.70–0.40) -0.40 (-3.60-1.25) 0.625 BMI, kg/m² -0.28 (-1.60-0.42) 0.204 -1.27 (-1.42–0.15) -0.13 (-1.27-0.43) 0.639 EE 0.27 (-0.98-1.19) 0.677 -0.48 (-0.84-0.93) 0.88 (-1.50-1.45) 1 LVEF, % 0.15 (-1.33-2.57) 0.733 -1.10 (-2.20-0.80) 1.00 (-0.70-2.65) 0.343 LAVI, mL/m² 1.00 (-4.15-6.10) 0.733 1.20 (-3.80-5.10) 0.80 (-3.05-7.00) 1 LAV, mL 1.55 (-7.45-9.92) 0.791 1.50 (-7.10-5.20) 1.60 (-4.80-12.55) 0.876 RVSP, mmHg 0.70 (-6.13-4.18) 0.45 1.90 (1.40-4.00) -4.00 (-7.55-2.35) 0.268 Creatinine, mg/dL -0.03 (-0.13-0.04) 0.241 -0.05 (-0.10-0.04) 0.00 (-0.15-0.03) 0.871 NT-proBNP, pg/mL -209.00 (-309.52-22.50) 0.151 24.00 (-277.00-236.00) -279.20 (-401.15–136.65) 0.106 Total Body Water, L -0.10 (-0.60-0.65) 0.838 -0.50 (-1.90–0.20) 0.60 (-0.25-1.35) 0.073 ICW, L -0.25 (-0.65-0.42) 0.569 -0.60 (-1.40–0.50) 0.30 (-0.25-0.95) 0.048 ECW, L 0.00 (-0.10-0.32) 0.541 -0.10 (-0.50-0.00) 0.10 (-0.05-0.55) 0.222 ECW/TBW 0.00 (0.00-0.01) 0.026 0.01 (0.01–0.01) 0.00 (0.00–0.00) 0.086 Phase Angle 0.10 (-0.23-0.52) 0.373 -0.20 (-0.30-0.10) 0.50 (0.25–0.70) 0.03 Phase Angle T-score 0.15 (-0.32-0.72) 0.328 -0.30 (-0.40–0.20) 0.70 (0.35-1.00) 0.03 Phase Angle Z-score 0.15 (-0.25-0.82) 0.373 -0.20 (-0.40–0.10) 0.80 (0.35–1.05) 0.03 4. Discussion In this preliminary pilot study, we investigated changes in body composition in overweight patients with persistent AF following cryoablation. While the overall cohort showed only modest, non-significant changes, a subgroup analysis revealed that the rhythm outcome was strongly associated with significant changes in markers of systemic cellular health. Our main finding is that patients who successfully maintained sinus rhythm (NSR group) exhibited a statistically significant improvement in both intracellular water (ICW) and all phase angle parameters. In contrast, patients with AF recurrence (PEF group) showed a consistent decline in these same markers. These findings suggest that successful rhythm control may promote systemic recovery, which is detectable by BIA. Mechanism of Body Water Changes: A Shift from Catabolism to Anabolism Our main finding is the divergent change in intracellular water (ICW), suggesting a shift from a persistent catabolic state in the PEF group to an anabolic recovery in the NSR group. Chronic AF is known to perpetuate a catabolic state, driven by systemic inflammation and neurohormonal activation that can lead to a reduction in body cell mass, of which ICW is a primary component [ 16 , 17 ]. Conversely, our results suggest that restoring sinus rhythm can reverse this process. Successful rhythm control improves cardiac efficiency, which likely mitigates the systemic inflammatory and neurohormonal insults characteristic of chronic AF [ 18 , 19 ]. This systemic stabilization creates a more favorable anabolic environment for cellular repair and rehydration. Therefore, the significant increase in ICW observed in the NSR group is not pathological fluid retention but rather a marker of improved lean body mass and cellular health [ 20 ]. Phase Angle as a Barometer of Cellular Recovery PhA is considered a global marker of cellular health, and numerous studies have demonstrated its prognostic value across various chronic conditions [ 21 – 24 ]. We hypothesized that successful ablation might lead to favorable changes in cellular function, reflected by an increase in PhA. Our results strongly support this hypothesis. The significant increase in phase angle and its standardized scores in the NSR group suggests that the benefits of restoring sinus rhythm extend beyond cardiac remodeling to a systemic cellular level. This recovery is likely multifaceted. First, successful rhythm control attenuates the chronic, low-grade inflammation and oxidative stress, that are intrinsically linked to AF [ 25 ]. This systemic inflammatory state is known to compromise cell membrane integrity, a key determinant of PhA [ 26 ]. Therefore, the restoration of sinus rhythm may lead to the recovery of cell membrane function, which is directly reflected as an improvement in PhA. Second, the hemodynamic stabilization following successful ablation likely mitigates the sustained neurohormonal activation, particularly of the renin-angiotensin-aldosterone system, which contributes to a systemic catabolic state in chronic AF [ 27 ]. The concurrent rise in ICW in our NSR group supports this notion, suggesting a favorable shift from catabolism to an anabolic state of cellular repair and rehydration. The divergence in PhA change between our groups suggests that persistent AF perpetuates systemic cellular distress, while restoring sinus rhythm may actively reverse it. Consequently, PhA could serve not just as a marker of nutritional status but as a dynamic barometer of systemic health in response to rhythm control therapy, capturing the integrated effects of reduced inflammation, improved hemodynamics, and cellular anabolic recovery. These observations are further supported by the explicit definition of arrhythmia recurrence and the structured monitoring strategy employed in this study. However, potential confounders such as changes in pharmacologic therapy—particularly diuretics or antiarrhythmic drugs—may have affected BIA results and were not tightly controlled. Going forward, larger trials should apply uniform follow-up protocols that include continuous or extended rhythm surveillance, systematic reporting of medication adjustments, and assessments of functional status such as exercise capacity or NYHA classification. Incorporating these elements will help to clarify whether phase angle can serve as a reliable biomarker of systemic recovery after ablation. Ultimately, validation in broader, multicenter populations will be necessary to determine whether PhA can complement ECG, echocardiography and natriuretic peptide testing as part of post-ablation follow-up. Limitations First, it is essential to emphasize that this is a preliminary, hypothesis-generating study with a small sample size. The statistical power is inherently limited, and the findings should be interpreted with caution as exploratory. This small cohort size likely contributed to the lack of statistical significance in some parameters, where a trend was observed but did not reach significance. While we observed a strong association between rhythm outcome and changes in PhA, this observational study cannot establish causality. It is plausible that patients with better underlying systemic health were more likely to maintain sinus rhythm, and the PhA changes are a reflection of this baseline condition rather than a consequence of rhythm control. A larger, prospective study, perhaps with serial measurements, would be needed to elucidate the temporal relationship and causal pathways between rhythm restoration and systemic cellular recovery. Second, this study focused on surrogate endpoints derived from BIA and echocardiography without incorporating patient-centered clinical outcomes. Data on changes in functional status, such as NYHA functional class, exercise capacity (e.g., 6-minute walk test), and clinical events like rehospitalization for heart failure, were not collected. Consequently, the direct clinical relevance of the observed changes in phase angle and intracellular water remains to be established. While these findings lay the groundwork for potential useof PhA as a biomarker for systemic recovery in the context of AF remains speculative and requires further validation. Third, as a single-center study, the findings may have limited generalizability. The patient population and procedural techniques may not be representative of other centers. Furthermore, the 6-month follow-up period may be insufficient to fully capture the long-term sustainability of rhythm control and the corresponding evolution of body composition and cardiac structural remodeling. Fourth, several potential confounders that could influence BIA measurements, such as dietary changes, physical activity levels, and medication adjustments (particularly diuretics), were not rigorously controlled for in this pilot study. Future studies should incorporate standardized protocols for these variables to isolate the effect of rhythm control on body composition. Finally, regarding the echocardiographic findings, the trend toward a reduction in RVSP in the NSR group is physiologically plausible and consistent with prior studies, which have shown that successful AF ablation can lead to left atrial reverse remodeling, reduced filling pressures, and a subsequent decrease in pulmonary pressures [ 28 , 29 ]. However, we did not observe significant changes in LAVI itself. This lack of difference is likely attributable to the small sample size and a relatively short follow-up period, as structural remodeling is a process that may evolve over a longer timeframe. Despite these limitations, our findings provide early evidence that systemic recovery after rhythm control in AF may be captured by BIA-derived metrics, which are simple, non-invasive, and repeatable, making them attractive adjuncts for monitoring recovery in clinical practice. These initial results provide a strong rationale for future, large-scale, multi-center prospective studies designed to validate these findings, establish the long-term prognostic value of BIA parameters, and correlate them with hard clinical outcomes in patients with atrial fibrillation. 5. Conclusion In this pilot study of overweight patients with persistent AF, the successful maintenance of sinus rhythm after cryoablation was associated with a favorable change in intracellular water and phase angle. While these results provide preliminary evidence supporting BIA-derived parameters as potential indicators of systemic recovery, they should be interpreted with caution, given the small sample size and the absence of clinical outcome measures.Future large-scale, multicenter studies are required to confirm these associations and to determine the prognostic utility of PhA in the follow-up of patients undergoing AF ablation. Abbreviations • AF Atrial Fibrillation • BIA Bioelectrical Impedance Analysis • BMI Body Mass Index • CT Computed Tomography • DCCV Direct Current Cardioversion • ECG Electrocardiogram • ECW Extracellular Water • ICE Intracardiac Echocardiography • ICW Intracellular Water • IQR Interquartile Range • LA Left Atrial • LAVI Left Atrial Volume Index • LVEF Left Ventricular Ejection Fraction • NSR Normal Sinus Rhythm • NT-proBNP N-terminal pro-B-type natriuretic peptide • PEF Persistent/Recurrent Atrial Fibrillation • PhA Phase Angle • PV Pulmonary Vein • RVSP Right Ventricular Systolic Pressure • SVC Superior Vena Cava • TBW Total Body Water Declarations Ethics approval and consent to participate: This study was approved by the Institutional Review Board of St. Vincent’s Hospital, The Catholic University of Korea (IRB No. VC24OISI0017) and was conducted in accordance with the principles of the Declaration of Helsinki. Written informed consent was obtained from all participants. Consent for publication: Not applicable. Competing interests: The authors declare no conflicts of interest. Clinical trial number not applicable. Funding: Not applicable. Author Contribution YMH designed and performed the experiments, derived the models, and analysed the data. SJK, KK assisted with measurements. SSC, first author, took the lead in writing the manuscript. All authors provided critical feedback and contributed to shaping the research, analysis, and manuscript. Data Availability The data that support the findings of this study are not openly available due to reasons of sensitivity and are available from the corresponding author upon reasonable request. 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Colin-Ramirez E, Castillo-Martinez L, Orea-Tejeda A, Vazquez-Duran M, Rodriguez AE, Keirns-Davis C. Bioelectrical impedance phase angle as a prognostic marker in chronic heart failure. Nutrition. 2012;28(9):901–5. Lukaski HC. Evolution of bioimpedance: a circuitous journey from estimation of physiological function to assessment of body composition and a return to clinical research. Eur J Clin Nutr. 2013;67(Suppl 1):S2–9. Anker SD, Sharma R. The syndrome of cardiac cachexia. Int J Cardiol. 2002;85(1):51–66. Mirzai S, Eck BL, Chen PH, Estep JD, Tang WHW. Current Approach to the Diagnosis of Sarcopenia in Heart Failure: A Narrative Review on the Role of Clinical and Imaging Assessments. Circ Heart Fail. 2022;15(10):e009322. Camm AJ, Naccarelli GV, Mittal S, Crijns H, Hohnloser SH, Ma CS, et al. The Increasing Role of Rhythm Control in Patients With Atrial Fibrillation: JACC State-of-the-Art Review. J Am Coll Cardiol. 2022;79(19):1932–48. Schreiber T, Grune J, Landmesser U, Attanasio P. Detection and modification of biomarkers of inflammation determining successful rhythm control in patients with atrial fibrillation. Biomarkers. 2023;28(8):681–91. Wabel P, Chamney P, Moissl U, Jirka T. Importance of whole-body bioimpedance spectroscopy for the management of fluid balance. Blood Purif. 2009;27(1):75–80. Schwenk A, Beisenherz A, Romer K, Kremer G, Salzberger B, Elia M. Phase angle from bioelectrical impedance analysis remains an independent predictive marker in HIV-infected patients in the era of highly active antiretroviral treatment. Am J Clin Nutr. 2000;72(2):496–501. Toso S, Piccoli A, Gusella M, Menon D, Bononi A, Crepaldi G, et al. Altered tissue electric properties in lung cancer patients as detected by bioelectric impedance vector analysis. Nutrition. 2000;16(2):120–4. Maggiore Q, Nigrelli S, Ciccarelli C, Grimaldi C, Rossi GA, Michelassi C. Nutritional and prognostic correlates of bioimpedance indexes in hemodialysis patients. Kidney Int. 1996;50(6):2103–8. Mattar JA. Application of total body bioimpedance to the critically ill patient. Brazilian Group for Bioimpedance Study. New Horiz. 1996;4(4):493–503. Korantzopoulos P, Letsas KP, Tse G, Fragakis N, Goudis CA, Liu T. Inflammation and atrial fibrillation: A comprehensive review. J Arrhythm. 2018;34(4):394–401. da Silva TK, Berbigier MC, Rubin Bde A, Moraes RB, Correa Souza G, Schweigert Perry ID. Phase angle as a prognostic marker in patients with critical illness. Nutr Clin Pract. 2015;30(2):261–5. Disertori M, Quintarelli S. Renin-Angiotensin System and AtrialFibrillation:Understanding the Connection. J Atr Fibrillation. 2011;4(4):398. Choi YY, Choi JI, Jeong JH, Lee HS, Kim YG, Kim MN, et al. Impact of pulmonary artery pressure on recurrence after catheter ablation in patients with atrial fibrillation. Front Cardiovasc Med. 2023;10:1187774. Almroth H, Karlsson LO, Carlhall CJ, Charitakis E. Haemodynamic changes after atrial fibrillation initiation in patients eligible for catheter ablation: a randomized controlled study. Eur Heart J Open. 2023;3(6):oead112. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 13 Feb, 2026 Read the published version in BMC Cardiovascular Disorders → Version 1 posted Editorial decision: Revision requested 18 Dec, 2025 Reviews received at journal 16 Dec, 2025 Reviewers agreed at journal 08 Dec, 2025 Reviewers agreed at journal 08 Dec, 2025 Reviews received at journal 24 Nov, 2025 Reviewers agreed at journal 24 Nov, 2025 Reviewers invited by journal 05 Oct, 2025 Editor invited by journal 23 Sep, 2025 Editor assigned by journal 22 Sep, 2025 Submission checks completed at journal 22 Sep, 2025 First submitted to journal 16 Sep, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Catholic University of Korea","correspondingAuthor":false,"prefix":"","firstName":"Kyunyeon","middleName":"","lastName":"Kim","suffix":""},{"id":530340875,"identity":"83e7b09e-f151-427b-9647-99cba32ec7f1","order_by":2,"name":"Sung Jung Kim","email":"","orcid":"","institution":"St. Vincent’s Hospital, The Catholic University of Korea","correspondingAuthor":false,"prefix":"","firstName":"Sung","middleName":"Jung","lastName":"Kim","suffix":""},{"id":530340876,"identity":"e5a9075e-a877-41a4-aaf9-0ebb4093be32","order_by":3,"name":"YouMi Hwang","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAy0lEQVRIiWNgGAWjYLCCBAMbHvvjDSRpqUiTYzhzgCRrzhwyZriRQKRig+M9phseth1IbJz59uBnnop7DPzt3fg1G5w5Y3Yjse1OYrN0XrI0z5liBokzZzfg13IjB6TlWWKbdI6B5My2BAYDiVyitBxO7JE8Y/xz5j9itSScOWwsIcFjJvGxgQgtkmeOld0ABbIBT46ZxYdjCTwE/cJ3vHnbzR/AqDRgP2N8I6EmQY6/vRe/FoUDaAI8eJWDgHwDQSWjYBSMglEw4gEAtFVO3Q8/X3IAAAAASUVORK5CYII=","orcid":"","institution":"St. Vincent’s Hospital, The Catholic University of Korea","correspondingAuthor":true,"prefix":"","firstName":"YouMi","middleName":"","lastName":"Hwang","suffix":""}],"badges":[],"createdAt":"2025-09-16 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05:16:39","extension":"xml","order_by":3,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":97993,"visible":true,"origin":"","legend":"","description":"","filename":"5cbbebe09baf45be8e144f820c01edf51structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-7631336/v1/d9db6a5555ed3d0721371f05.xml"},{"id":93822904,"identity":"65a08cfd-337f-4d1c-9775-da4f0a5c1212","added_by":"auto","created_at":"2025-10-18 05:08:38","extension":"html","order_by":4,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":105704,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-7631336/v1/aa24fa1955683be77a032248.html"},{"id":102785478,"identity":"35981008-1c09-4e8e-808f-156c457f028a","added_by":"auto","created_at":"2026-02-16 16:07:19","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":924855,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7631336/v1/1bd0b772-6f5b-451f-b874-6b405692eded.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Exploratory Phase Angle Assessment After Atrial Fibrillation Ablation in Overweight Patients: A Pilot Study","fulltext":[{"header":"1. Background","content":"\u003cp\u003eAtrial fibrillation (AF) is the most common arrhythmia, increasing with age, and its prevalence is projected to grow substantially [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. It is associated with significant morbidity, including stroke and heart failure, thereby impairing quality of life [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. The pathophysiology of AF involves profound hemodynamic consequences; the loss of coordinated atrial contraction and an irregular ventricular response can reduce cardiac output, leading to systemic hypoperfusion and neurohormonal activation [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. These changes promote fluid retention, a key feature in AF-related heart failure. Beyond its direct arrhythmogenic effects, AF is increasingly recognized as a systemic condition associated with chronic inflammation and neurohormonal activation [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. These processes contribute to adverse body composition changes, such as sarcopenia and cardiac cachexia, which are potent independent predictors of poor outcomes in AF patients [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Furthermore, obesity is a well-established risk factor for the development and progression of AF and is associated with lower success rates after catheter ablation [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. The underlying mechanisms are complex, involving structural changes like left atrial enlargement, epicardial adipose tissue, and systemic inflammation [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Given this intricate relationship, understanding how rhythm control impacts body composition, particularly in overweight individuals, is of significant clinical importance. This highlights the need for tools that can assess the systemic burden of AF beyond traditional cardiac metrics. Bioelectrical Impedance Analysis (BIA) is a validated, non-invasive method for assessing body composition and fluid status in patients with cardiac conditions [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. While parameters such as the ratio of extracellular to total body water (ECW/TBW) can be used to quantify fluid overload [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e], the phase angle (PhA) has emerged as a particularly valuable metric for this purpose. The PhA is a robust indicator of cellular health and membrane integrity [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. A lower PhA reflects compromised cell membranes and is a powerful predictor of mortality in chronic diseases, particularly heart failure [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. It is considered an objective measure of systemic health, integrating information on fluid balance, nutritional status, and inflammation [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eWhile rhythm control strategies for AF aim to improve cardiac function, their impact on systemic cellular integrity has not been fully elucidated. This is the first preliminary study to comprehensively evaluate changes in body water composition and phase angle in overweight patients with atrial fibrillation following cryoablation.\u003c/p\u003e"},{"header":"2. Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003e2.1 Study Population and Design\u003c/h2\u003e\u003cp\u003e This prospective, single-center, observational pilot study was approved by the Institutional Review Board of St. Vincent\u0026rsquo;s Hospital, The Catholic University of Korea (IRB No. VC24OISI0017), and all participants provided written informed consent. The study was conducted in accordance with the principles of the Declaration of Helsinki. We enrolled 13 patients diagnosed with persistent atrial fibrillation who were scheduled for rhythm control therapy. The inclusion criteria were: 1) age\u0026thinsp;\u0026ge;\u0026thinsp;20 years, and 2) overweight, defined as a Body Mass Index (BMI)\u0026thinsp;\u0026ge;\u0026thinsp;23 kg/m\u0026sup2;. Baseline characteristics, echocardiographic data, and BIA parameters were collected before the procedure. All patients underwent follow-up assessments, including BIA and echocardiography, after 6 months (\u0026plusmn;\u0026thinsp;1 month) after the ablation. One patient was excluded from the follow-up analysis due to the aggravation of sick sinus syndrome requiring permanent pacemaker implantation after the procedure. Consequently, the final analysis of post-ablation changes was performed on 12 patients.\u003c/p\u003e\u003cp\u003eThe primary outcome was the change in phase angle from baseline to 6 months, stratified by rhythm outcome. Secondary outcomes included changes in intracellular water (ICW), total body water (TBW), extracellular water (ECW), and echocardiographic parameters such as LVEF, LAVI, and E/e\u0026rsquo;.\u003c/p\u003e\u003cp\u003eAF recurrence was defined as any episode of atrial tachyarrhythmia lasting\u0026thinsp;\u0026ge;\u0026thinsp;30 seconds, confirmed by 12-lead ECG, 24-hour Holter monitoring, or event recorder, beyond a 3-month blanking period. All patients underwent a scheduled ECG at each follow-up outpatient clinic visit, and a symptom-triggered ECG or Holter monitor was performed when clinically indicated. \u003cb\u003e2.2 Procedure\u003c/b\u003e\u003c/p\u003e\u003cdiv id=\"Sec4\" class=\"Section3\"\u003e\u003ch2\u003e2.2.1 Cryoablation\u003c/h2\u003e\u003cp\u003eAll procedures were performed in fasting patients under conscious sedation, which was maintained with a continuous infusion of remifentanil. Following local anesthesia with 1% lidocaine, percutaneous vascular access was obtained from the right and left femoral veins. A 5Fr diagnostic catheter (typically quadripolar or decapolar) was positioned in the superior vena cava (SVC) for pacing and monitoring. A single transseptal puncture was performed under fluoroscopic and hemodynamic guidance to access the left atrium. In one of the nine cases, intracardiac echocardiography (ICE) was also utilized for guidance. An 8.5Fr SL1 sheath was used for the puncture and subsequently exchanged for a 15Fr steerable sheath (FlexCath Advance\u0026trade;, Medtronic, Minneapolis, MN, USA). A 28 mm second-generation cryoballoon catheter (Arctic Front Advance Pro\u0026trade;, Medtronic) and an integrated circular mapping catheter (Achieve\u0026trade;, Medtronic) were then advanced into the left atrium. The procedure consisted of the complete electrical isolation of all four pulmonary veins (PVs). The target ablation temperature was typically between \u0026minus;\u0026thinsp;40\u0026deg;C and \u0026minus;\u0026thinsp;60\u0026deg;C. During ablation of the right-sided PVs, the phrenic nerve was continuously monitored by high-output pacing from the catheter in the SVC to prevent phrenic nerve injury. After successful pulmonary vein isolation, patients underwent synchronized direct current cardioversion (DCCV) under deep sedation with intravenous etomidate to restore sinus rhythm. The procedure was completed without any immediate complications.\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e\u003ch2\u003e2.3 Data Collection\u003c/h2\u003e\u003cp\u003eClinical, echocardiographic, and bioelectrical impedance analysis (BIA) data were collected at baseline and the 6-month follow-up visit. Clinical data included demographics, comorbidities, and medications. Blood samples were collected for serum creatinine and N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels. At baseline, cardiac computed tomography (CT) was also performed to measure the left atrial (LA) diastolic volume, excluding the appendage. Transthoracic echocardiography was performed to assess left ventricular ejection fraction (LVEF), left atrial volume index (LAVI), E/e', and right ventricular systolic pressure (RVSP). Body composition was measured using a multi-frequency BIA device (InBody BWA2.0, InBody Co., Ltd, Seoul, Korea). Patients were instructed to fast for at least 4 hours before the measurement. All measurements were taken in a standing position, with electrodes attached to the hands and feet according to the manufacturer's protocol. Baseline computed tomography left atrial volume (CT LAV) data were missing for one patient in the PEF group and were thus excluded from the relevant analyses.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec6\" class=\"Section2\"\u003e\u003ch2\u003e2.4 Statistical Analysis\u003c/h2\u003e\u003cp\u003eAs this was a preliminary study with a small sample size, non-parametric tests were employed for statistical analysis. Data are presented as median (interquartile range) for continuous variables and n (%) for categorical variables. To compare baseline characteristics between the two groups, the Mann-Whitney U test was used for continuous variables, and Fisher's exact test was used for categorical variables. Changes in parameters from baseline to follow-up were also analyzed between the groups using the Mann-Whitney U test. A p-value of less than 0.05 was considered statistically significant. All analyses were performed using R statistical software (version 4.2.3; R Foundation for Statistical Computing, Vienna, Austria).\u003c/p\u003e\u003c/div\u003e"},{"header":"3. Results","content":"\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\u003ch2\u003e3.1 Baseline Characteristics\u003c/h2\u003e\u003cp\u003eThe baseline characteristics of the 13 enrolled patients are summarized in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. The median age of the total cohort was 60.0 years (IQR 58.0\u0026ndash;66.0), and 11 patients (84.6%) were male. The median BMI was 27.7 kg/m\u0026sup2; (IQR 25.7\u0026ndash;30.0). At the 6-month follow-up, five patients were assigned to the PEF group (AF recurrence) and 8 to the NSR group (sinus rhythm maintained). When comparing the two groups at baseline, no statistically significant differences were found in clinical demographics or comorbidities. The median age was 61.0 years (IQR, 58.0\u0026ndash;67.0) in the PEF group and 59.5 years (IQR, 54.8\u0026ndash;64.8) in the NSR group (p\u0026thinsp;=\u0026thinsp;0.585). BMI was also similar between the groups (PEF: 25.5 kg/m\u0026sup2; [IQR 24.7\u0026ndash;26.8] vs. NSR: 28.4 kg/m\u0026sup2; [IQR 24.9\u0026ndash;29.8]; p\u0026thinsp;=\u0026thinsp;0.222). Echocardiographic parameters, including LVEF (PEF: 56.3% [IQR 50.9\u0026ndash;63.9] vs. NSR: 57.9% [IQR 57.1\u0026ndash;64.2]; p\u0026thinsp;=\u0026thinsp;0.643) and LAVI (PEF: 50.3 mL/m\u0026sup2; [IQR 39.5\u0026ndash;81.8] vs. NSR: 40.5 mL/m\u0026sup2; [IQR 31.7\u0026ndash;44.1]; p\u0026thinsp;=\u0026thinsp;0.176), did not differ significantly. All baseline BIA parameters were also comparable between the two groups, whole-body phase angle was 7.0 (IQR 6.1\u0026ndash;7.3) in the PEF group and 6.4 (IQR 5.5\u0026ndash;7.1) in the NSR group (p\u0026thinsp;=\u0026thinsp;0.251), and the ECW/TBW ratio was 0.382 (IQR 0.381\u0026ndash;0.395) in the PEF group versus 0.388 (IQR 0.372\u0026ndash;0.389) in the NSR group (p\u0026thinsp;=\u0026thinsp;0.643).\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 Characteristics (n\u0026thinsp;=\u0026thinsp;13)\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=\"char\" char=\".\" 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\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eTotal (n\u0026thinsp;=\u0026thinsp;13)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"3\" nameend=\"c5\" namest=\"c3\"\u003e\u003cp\u003eFinal Rhythm\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003ePEF (n\u0026thinsp;=\u0026thinsp;5)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eNSR (n\u0026thinsp;=\u0026thinsp;8)\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\u003e\u003cb\u003eAge, years\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e60.00 (58.00\u0026ndash;66.00)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e61.0 (58.0\u0026ndash;67.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e59.5 (54.8\u0026ndash;64.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.585\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eSex, male\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e11 (84.6%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4 (80.0%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e7 (87.5%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eWeight, kg\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e81.10 (72.40\u0026ndash;91.90)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e72.4 (64.8\u0026ndash;77.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e83.0 (66.7\u0026ndash;90.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.312\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eBMI, kg/m\u0026sup2;\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e27.74 (25.65\u0026ndash;30.04)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e25.5 (24.7\u0026ndash;26.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e28.4 (24.9\u0026ndash;29.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.222\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eHypertension\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e9 (69.2%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4 (80.0%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e5 (62.5%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eDiabetes mellitus\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e5 (38.5%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3 (60.0%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2 (25.0%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.282\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eDyslipidemia\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e9 (69.2%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4 (80.0%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e5 (62.5%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eCOPD\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0 (0.0%)\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\u003e0 (0.0%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eCKD\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1 (7.7%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1 (20.0%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0 (0.0%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.417\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eE/e'\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e7.96 (6.61\u0026ndash;9.50)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e7.4 (7.0-19.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e7.9 (6.1\u0026ndash;8.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.812\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eLVEF, %\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e57.90 (56.30\u0026ndash;62.50)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e56.3 (50.9\u0026ndash;63.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e57.9 (57.1\u0026ndash;64.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.643\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eLAVI, mL/m\u0026sup2;\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e40.50 (37.60\u0026ndash;50.30)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e50.3 (39.5\u0026ndash;81.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e40.5 (31.7\u0026ndash;44.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.176\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eLAV, mL\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e81.90 (62.60\u0026ndash;93.50)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e93.5 (78.9-152.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e81.9 (62.2\u0026ndash;87.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.141\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eRVSP, mmHg\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e27.60 (25.60\u0026ndash;35.90)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e38.0 (27.9\u0026ndash;45.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e27.6 (25.3\u0026ndash;35.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.199\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eCT LAV, mL*\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e230.11 (213.91-280.93)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e215.0 (193.3\u0026ndash;228.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e207.2 (172.9-224.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eCreatinine, mg/dL\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1.00 (0.90\u0026ndash;1.10)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.1 (0.9\u0026ndash;2.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.0 (0.8\u0026ndash;1.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.251\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eNT-proBNP, pg/mL\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e414.00 (266.00-631.00)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e644.0 (318.0-2603.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e379.0 (143.0-414.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.141\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eTotal Body Water, L\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e42.90 (39.60\u0026ndash;45.10)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e43.9 (37.2\u0026ndash;44.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e43.0 (38.8\u0026ndash;48.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.812\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eICW, L\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e26.50 (24.30\u0026ndash;28.50)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e26.5 (22.5\u0026ndash;27.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e27.8 (23.9\u0026ndash;29.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.812\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eECW, L\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e16.60 (15.00-17.30)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e17.3 (14.7\u0026ndash;17.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e16.6 (14.9\u0026ndash;19.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eECW/TBW\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.38 (0.38\u0026ndash;0.39)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.382 (0.381\u0026ndash;0.395)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.388 (0.372\u0026ndash;0.389)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.643\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003ePhase Angle\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e6.60 (6.20\u0026ndash;7.30)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e7.0 (6.1\u0026ndash;7.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e6.4 (5.5\u0026ndash;7.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.251\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003ePhase Angle T-score\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e-1.10 (-2.20-0.00)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-0.9 (-1.2 to -0.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-1.0 (-2.0 to -0.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.812\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003ePhase Angle Z-score\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.20 (-1.00-0.30)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.2 (-0.9 to 0.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.1 (-1.1 to 0.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec9\" class=\"Section2\"\u003e\u003ch2\u003e3.2 Changes in Body Composition and Echocardiographic Parameters\u003c/h2\u003e\u003cp\u003eThe changes in parameters for the 12 patients who completed follow-up are presented in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. When analyzed as a single cohort, there were no statistically significant changes from baseline to follow-up in any of the parameters. However, the subgroup analysis based on rhythm outcome revealed substantial changes, particularly in the BIA parameters. Changes in body weight (PEF: -3.60 kg vs. NSR: -0.40 kg; p\u0026thinsp;=\u0026thinsp;0.625) and BMI (PEF: -1.27 kg/m\u0026sup2; vs. NSR: -0.13 kg/m\u0026sup2;; p\u0026thinsp;=\u0026thinsp;0.639) were not significantly different between the groups. Similarly, changes in echocardiographic parameters such as LVEF (PEF: -1.10% vs. NSR: +1.00%; p\u0026thinsp;=\u0026thinsp;0.343), LAVI (PEF: +1.2 mL/m\u0026sup2; vs. NSR: +0.8 mL/m\u0026sup2;; p\u0026thinsp;=\u0026thinsp;1.00), and E/e' (PEF: -0.48 vs. NSR: +0.88; p\u0026thinsp;=\u0026thinsp;1.000) did not show significant differences. However, the change in Intracellular Water (ICW) was significantly different, showing a median decrease of -0.60 L (IQR \u0026minus;\u0026thinsp;1.40 to -0.50) in the PEF group versus a median increase of 0.30 L (IQR \u0026minus;\u0026thinsp;0.25 to 0.95) in the NSR group (p\u0026thinsp;=\u0026thinsp;0.048). Furthermore, the change in the phase angle was also significantly different. The PEF group showed a median decrease of -0.20 (IQR \u0026minus;\u0026thinsp;0.30 to -0.10), whereas the NSR group showed a significant median increase of 0.50 (IQR 0.25 to 0.70) (p\u0026thinsp;=\u0026thinsp;0.03). This significant opposing trend was consistent across all phase angle-related variables. The changes in the Phase Angle T-score (PEF: -0.20 vs. NSR: +0.70; p\u0026thinsp;=\u0026thinsp;0.03) and Z-score (PEF: -0.20 vs. NSR: +0.80; p\u0026thinsp;=\u0026thinsp;0.03) were also significantly different between the two groups. In contrast, other BIA variables, including Total Body Water (PEF: -0.50 L vs. NSR: +0.60 L; p\u0026thinsp;=\u0026thinsp;0.073), Extracellular Water (PEF: +0.20 L vs. NSR: +0.50 L; p\u0026thinsp;=\u0026thinsp;0.343), and the ECW/TBW ratio (PEF: +0.01 vs. NSR: 0.00; p\u0026thinsp;=\u0026thinsp;0.086), did not show statistically significant differences between the groups.\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\u003eComparison of Changes in Parameters at 6-Month Follow-up, Stratified by Rhythm Outcome (n\u0026thinsp;=\u0026thinsp;12)\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=\"char\" char=\"\u0026minus;\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" 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\" morerows=\"1\" rowspan=\"2\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eTotal (n\u0026thinsp;=\u0026thinsp;12)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eP-value\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e\u003cp\u003eFinal Rhythm\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003ePEF (n\u0026thinsp;=\u0026thinsp;5)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eNSR (n\u0026thinsp;=\u0026thinsp;8)\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\"\u003e\u003cp\u003e\u003cb\u003eWeight, kg\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026minus;\" colname=\"c2\"\u003e\u003cp\u003e-0.80 (-5.03-1.17)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.176\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-3.60 (-4.70\u0026ndash;0.40)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-0.40 (-3.60-1.25)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.625\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eBMI, kg/m\u0026sup2;\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026minus;\" colname=\"c2\"\u003e\u003cp\u003e-0.28 (-1.60-0.42)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.204\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-1.27 (-1.42\u0026ndash;0.15)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-0.13 (-1.27-0.43)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.639\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eEE\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026minus;\" colname=\"c2\"\u003e\u003cp\u003e0.27 (-0.98-1.19)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.677\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-0.48 (-0.84-0.93)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.88 (-1.50-1.45)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eLVEF, %\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026minus;\" colname=\"c2\"\u003e\u003cp\u003e0.15 (-1.33-2.57)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.733\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-1.10 (-2.20-0.80)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1.00 (-0.70-2.65)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.343\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eLAVI, mL/m\u0026sup2;\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026minus;\" colname=\"c2\"\u003e\u003cp\u003e1.00 (-4.15-6.10)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.733\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.20 (-3.80-5.10)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.80 (-3.05-7.00)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eLAV, mL\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026minus;\" colname=\"c2\"\u003e\u003cp\u003e1.55 (-7.45-9.92)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.791\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.50 (-7.10-5.20)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1.60 (-4.80-12.55)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.876\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eRVSP, mmHg\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026minus;\" colname=\"c2\"\u003e\u003cp\u003e0.70 (-6.13-4.18)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.45\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.90 (1.40-4.00)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-4.00 (-7.55-2.35)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.268\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eCreatinine, mg/dL\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026minus;\" colname=\"c2\"\u003e\u003cp\u003e-0.03 (-0.13-0.04)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.241\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-0.05 (-0.10-0.04)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.00 (-0.15-0.03)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.871\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eNT-proBNP, pg/mL\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026minus;\" colname=\"c2\"\u003e\u003cp\u003e-209.00 (-309.52-22.50)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.151\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e24.00 (-277.00-236.00)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-279.20 (-401.15\u0026ndash;136.65)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.106\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eTotal Body Water, L\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026minus;\" colname=\"c2\"\u003e\u003cp\u003e-0.10 (-0.60-0.65)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.838\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-0.50 (-1.90\u0026ndash;0.20)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.60 (-0.25-1.35)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.073\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eICW, L\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026minus;\" colname=\"c2\"\u003e\u003cp\u003e-0.25 (-0.65-0.42)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.569\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-0.60 (-1.40\u0026ndash;0.50)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.30 (-0.25-0.95)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.048\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eECW, L\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026minus;\" colname=\"c2\"\u003e\u003cp\u003e0.00 (-0.10-0.32)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.541\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-0.10 (-0.50-0.00)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.10 (-0.05-0.55)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.222\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eECW/TBW\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026minus;\" colname=\"c2\"\u003e\u003cp\u003e0.00 (0.00-0.01)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.026\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.01 (0.01\u0026ndash;0.01)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.00 (0.00\u0026ndash;0.00)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.086\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003ePhase Angle\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026minus;\" colname=\"c2\"\u003e\u003cp\u003e0.10 (-0.23-0.52)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.373\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-0.20 (-0.30-0.10)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.50 (0.25\u0026ndash;0.70)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.03\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003ePhase Angle T-score\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026minus;\" colname=\"c2\"\u003e\u003cp\u003e0.15 (-0.32-0.72)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.328\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-0.30 (-0.40\u0026ndash;0.20)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.70 (0.35-1.00)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.03\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003ePhase Angle Z-score\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026minus;\" colname=\"c2\"\u003e\u003cp\u003e0.15 (-0.25-0.82)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.373\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-0.20 (-0.40\u0026ndash;0.10)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.80 (0.35\u0026ndash;1.05)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.03\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003c/div\u003e"},{"header":"4. Discussion","content":"\u003cp\u003eIn this preliminary pilot study, we investigated changes in body composition in overweight patients with persistent AF following cryoablation. While the overall cohort showed only modest, non-significant changes, a subgroup analysis revealed that the rhythm outcome was strongly associated with significant changes in markers of systemic cellular health. Our main finding is that patients who successfully maintained sinus rhythm (NSR group) exhibited a statistically significant improvement in both intracellular water (ICW) and all phase angle parameters. In contrast, patients with AF recurrence (PEF group) showed a consistent decline in these same markers. These findings suggest that successful rhythm control may promote systemic recovery, which is detectable by BIA.\u003c/p\u003e\u003cp\u003e\u003cb\u003eMechanism of Body Water Changes: A Shift from Catabolism to Anabolism\u003c/b\u003e\u003c/p\u003e\u003cp\u003eOur main finding is the divergent change in intracellular water (ICW), suggesting a shift from a persistent catabolic state in the PEF group to an anabolic recovery in the NSR group. Chronic AF is known to perpetuate a catabolic state, driven by systemic inflammation and neurohormonal activation that can lead to a reduction in body cell mass, of which ICW is a primary component [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. Conversely, our results suggest that restoring sinus rhythm can reverse this process. Successful rhythm control improves cardiac efficiency, which likely mitigates the systemic inflammatory and neurohormonal insults characteristic of chronic AF [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. This systemic stabilization creates a more favorable anabolic environment for cellular repair and rehydration. Therefore, the significant increase in ICW observed in the NSR group is not pathological fluid retention but rather a marker of improved lean body mass and cellular health [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e].\u003c/p\u003e\u003cp\u003e\u003cb\u003ePhase Angle as a Barometer of Cellular Recovery\u003c/b\u003e\u003c/p\u003e\u003cp\u003ePhA is considered a global marker of cellular health, and numerous studies have demonstrated its prognostic value across various chronic conditions [\u003cspan additionalcitationids=\"CR22 CR23\" citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. We hypothesized that successful ablation might lead to favorable changes in cellular function, reflected by an increase in PhA. Our results strongly support this hypothesis. The significant increase in phase angle and its standardized scores in the NSR group suggests that the benefits of restoring sinus rhythm extend beyond cardiac remodeling to a systemic cellular level. This recovery is likely multifaceted.\u003c/p\u003e\u003cp\u003eFirst, successful rhythm control attenuates the chronic, low-grade inflammation and oxidative stress, that are intrinsically linked to AF [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. This systemic inflammatory state is known to compromise cell membrane integrity, a key determinant of PhA [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. Therefore, the restoration of sinus rhythm may lead to the recovery of cell membrane function, which is directly reflected as an improvement in PhA.\u003c/p\u003e\u003cp\u003eSecond, the hemodynamic stabilization following successful ablation likely mitigates the sustained neurohormonal activation, particularly of the renin-angiotensin-aldosterone system, which contributes to a systemic catabolic state in chronic AF [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. The concurrent rise in ICW in our NSR group supports this notion, suggesting a favorable shift from catabolism to an anabolic state of cellular repair and rehydration.\u003c/p\u003e\u003cp\u003eThe divergence in PhA change between our groups suggests that persistent AF perpetuates systemic cellular distress, while restoring sinus rhythm may actively reverse it. Consequently, PhA could serve not just as a marker of nutritional status but as a dynamic barometer of systemic health in response to rhythm control therapy, capturing the integrated effects of reduced inflammation, improved hemodynamics, and cellular anabolic recovery.\u003c/p\u003e\u003cp\u003eThese observations are further supported by the explicit definition of arrhythmia recurrence and the structured monitoring strategy employed in this study. However, potential confounders such as changes in pharmacologic therapy\u0026mdash;particularly diuretics or antiarrhythmic drugs\u0026mdash;may have affected BIA results and were not tightly controlled. Going forward, larger trials should apply uniform follow-up protocols that include continuous or extended rhythm surveillance, systematic reporting of medication adjustments, and assessments of functional status such as exercise capacity or NYHA classification. Incorporating these elements will help to clarify whether phase angle can serve as a reliable biomarker of systemic recovery after ablation. Ultimately, validation in broader, multicenter populations will be necessary to determine whether PhA can complement ECG, echocardiography and natriuretic peptide testing as part of post-ablation follow-up.\u003c/p\u003e\u003cp\u003e\u003cb\u003eLimitations\u003c/b\u003e\u003c/p\u003e\u003cp\u003eFirst, it is essential to emphasize that this is a preliminary, hypothesis-generating study with a small sample size. The statistical power is inherently limited, and the findings should be interpreted with caution as exploratory. This small cohort size likely contributed to the lack of statistical significance in some parameters, where a trend was observed but did not reach significance. While we observed a strong association between rhythm outcome and changes in PhA, this observational study cannot establish causality. It is plausible that patients with better underlying systemic health were more likely to maintain sinus rhythm, and the PhA changes are a reflection of this baseline condition rather than a consequence of rhythm control. A larger, prospective study, perhaps with serial measurements, would be needed to elucidate the temporal relationship and causal pathways between rhythm restoration and systemic cellular recovery.\u003c/p\u003e\u003cp\u003eSecond, this study focused on surrogate endpoints derived from BIA and echocardiography without incorporating patient-centered clinical outcomes. Data on changes in functional status, such as NYHA functional class, exercise capacity (e.g., 6-minute walk test), and clinical events like rehospitalization for heart failure, were not collected. Consequently, the direct clinical relevance of the observed changes in phase angle and intracellular water remains to be established. While these findings lay the groundwork for potential useof PhA as a biomarker for systemic recovery in the context of AF remains speculative and requires further validation.\u003c/p\u003e\u003cp\u003eThird, as a single-center study, the findings may have limited generalizability. The patient population and procedural techniques may not be representative of other centers. Furthermore, the 6-month follow-up period may be insufficient to fully capture the long-term sustainability of rhythm control and the corresponding evolution of body composition and cardiac structural remodeling.\u003c/p\u003e\u003cp\u003eFourth, several potential confounders that could influence BIA measurements, such as dietary changes, physical activity levels, and medication adjustments (particularly diuretics), were not rigorously controlled for in this pilot study. Future studies should incorporate standardized protocols for these variables to isolate the effect of rhythm control on body composition.\u003c/p\u003e\u003cp\u003eFinally, regarding the echocardiographic findings, the trend toward a reduction in RVSP in the NSR group is physiologically plausible and consistent with prior studies, which have shown that successful AF ablation can lead to left atrial reverse remodeling, reduced filling pressures, and a subsequent decrease in pulmonary pressures [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e, \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]. However, we did not observe significant changes in LAVI itself. This lack of difference is likely attributable to the small sample size and a relatively short follow-up period, as structural remodeling is a process that may evolve over a longer timeframe. Despite these limitations, our findings provide early evidence that systemic recovery after rhythm control in AF may be captured by BIA-derived metrics, which are simple, non-invasive, and repeatable, making them attractive adjuncts for monitoring recovery in clinical practice. These initial results provide a strong rationale for future, large-scale, multi-center prospective studies designed to validate these findings, establish the long-term prognostic value of BIA parameters, and correlate them with hard clinical outcomes in patients with atrial fibrillation.\u003c/p\u003e"},{"header":"5. Conclusion","content":"\u003cp\u003eIn this pilot study of overweight patients with persistent AF, the successful maintenance of sinus rhythm after cryoablation was associated with a favorable change in intracellular water and phase angle. While these results provide preliminary evidence supporting BIA-derived parameters as potential indicators of systemic recovery, they should be interpreted with caution, given the small sample size and the absence of clinical outcome measures.Future large-scale, multicenter studies are required to confirm these associations and to determine the prognostic utility of PhA in the follow-up of patients undergoing AF ablation.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u0026bull; \u003cb\u003eAF\u003c/b\u003e\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eAtrial Fibrillation\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u0026bull; \u003cb\u003eBIA\u003c/b\u003e\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eBioelectrical Impedance Analysis\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u0026bull; \u003cb\u003eBMI\u003c/b\u003e\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eBody Mass Index\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u0026bull; \u003cb\u003eCT\u003c/b\u003e\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eComputed Tomography\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u0026bull; \u003cb\u003eDCCV\u003c/b\u003e\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eDirect Current Cardioversion\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u0026bull; \u003cb\u003eECG\u003c/b\u003e\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eElectrocardiogram\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u0026bull; \u003cb\u003eECW\u003c/b\u003e\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eExtracellular Water\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u0026bull; \u003cb\u003eICE\u003c/b\u003e\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eIntracardiac Echocardiography\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u0026bull; \u003cb\u003eICW\u003c/b\u003e\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eIntracellular Water\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u0026bull; \u003cb\u003eIQR\u003c/b\u003e\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eInterquartile Range\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u0026bull; \u003cb\u003eLA\u003c/b\u003e\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eLeft Atrial\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u0026bull; \u003cb\u003eLAVI\u003c/b\u003e\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eLeft Atrial Volume Index\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u0026bull; \u003cb\u003eLVEF\u003c/b\u003e\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eLeft Ventricular Ejection Fraction\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u0026bull; \u003cb\u003eNSR\u003c/b\u003e\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eNormal Sinus Rhythm\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u0026bull; \u003cb\u003eNT-proBNP\u003c/b\u003e\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eN-terminal pro-B-type natriuretic peptide\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u0026bull; \u003cb\u003ePEF\u003c/b\u003e\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003ePersistent/Recurrent Atrial Fibrillation\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u0026bull; \u003cb\u003ePhA\u003c/b\u003e\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003ePhase Angle\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u0026bull; \u003cb\u003ePV\u003c/b\u003e\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003ePulmonary Vein\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u0026bull; \u003cb\u003eRVSP\u003c/b\u003e\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eRight Ventricular Systolic Pressure\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u0026bull; \u003cb\u003eSVC\u003c/b\u003e\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eSuperior Vena Cava\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u0026bull; \u003cb\u003eTBW\u003c/b\u003e\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eTotal Body Water\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate:\u003c/strong\u003e\u003cp\u003e This study was approved by the Institutional Review Board of St. Vincent\u0026rsquo;s Hospital, The Catholic University of Korea (IRB No. VC24OISI0017) and was conducted in accordance with the principles of the Declaration of Helsinki. Written informed consent was obtained from all participants.\u003c/p\u003e\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eConsent for publication:\u003c/strong\u003e\u003cp\u003eNot applicable.\u003c/p\u003e\u003c/p\u003e\u003cp\u003e\u003ch2\u003eCompeting interests:\u003c/h2\u003e\u003cp\u003eThe authors declare no conflicts of interest.\u003c/p\u003e\u003c/p\u003e\u003cp\u003e\u003ch2\u003eClinical trial number\u003c/h2\u003e\u003cp\u003enot applicable.\u003c/p\u003e\u003c/p\u003e\u003ch2\u003eFunding:\u003c/h2\u003e\u003cp\u003eNot applicable.\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eYMH designed and performed the experiments, derived the models, and analysed the data. SJK, KK assisted with measurements. SSC, first author, took the lead in writing the manuscript. All authors provided critical feedback and contributed to shaping the research, analysis, and manuscript.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eThe data that support the findings of this study are not openly available due to reasons of sensitivity and are available from the corresponding author upon reasonable request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eHindricks G, Potpara T, Dagres N, Arbelo E, Bax JJ, Blomstrom-Lundqvist C, et al. 2020 ESC Guidelines for the diagnosis and management of atrial fibrillation developed in collaboration with the European Association for Cardio-Thoracic Surgery (EACTS): The Task Force for the diagnosis and management of atrial fibrillation of the European Society of Cardiology (ESC) Developed with the special contribution of the European Heart Rhythm Association (EHRA) of the ESC. Eur Heart J. 2021;42(5):373\u0026ndash;498.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eStaerk L, Sherer JA, Ko D, Benjamin EJ, Helm RH. Atrial Fibrillation: Epidemiology, Pathophysiology, and Clinical Outcomes. Circ Res. 2017;120(9):1501\u0026ndash;17.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePfenniger A, Geist GE, Arora R. Autonomic Dysfunction and Neurohormonal Disorders in Atrial Fibrillation. Card Electrophysiol Clin. 2021;13(1):183\u0026ndash;90.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHarada M, Van Wagoner DR, Nattel S. Role of inflammation in atrial fibrillation pathophysiology and management. Circ J. 2015;79(3):495\u0026ndash;502.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZhang Y, Zhang J, Ni W, Yuan X, Zhang H, Li P, et al. Sarcopenia in heart failure: a systematic review and meta-analysis. ESC Heart Fail. 2021;8(2):1007\u0026ndash;17.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTang Y, Liu Z, Chen Q, Juaiti M, Yu Z, Liang B, et al. Association of sarcopenia with the long-term risk of atrial fibrillation: A prospective cohort study. Aging Cell. 2024;23(8):e14198.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWong CX, Sullivan T, Sun MT, Mahajan R, Pathak RK, Middeldorp M, et al. Obesity and the Risk of Incident, Post-Operative, and Post-Ablation Atrial Fibrillation: A Meta-Analysis of 626,603 Individuals in 51 Studies. JACC Clin Electrophysiol. 2015;1(3):139\u0026ndash;52.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAnagnostopoulos I, Kousta M, Kossyvakis C, Paraskevaidis NT, Vrachatis D, Deftereos S, et al. Epicardial Adipose Tissue and Atrial Fibrillation Recurrence following Catheter Ablation: A Systematic Review and Meta-Analysis. J Clin Med. 2023;12:19.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePopiolek-Kalisz J, Szczygiel K. Bioelectrical Impedance Analysis and Body Composition in Cardiovascular Diseases. Curr Probl Cardiol. 2023;48(11):101911.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDe Ponti C, Bonaventura A. Bioelectrical impedance analysis for early recognition of fluid congestion in heart failure: Is it the best tool? Int J Cardiol. 2024;413:132314.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eShibata K, Adachi T, Kameshima M, Kito H, Tanaka C, Sano T, et al. Prognostic impact of segmental extracellular water to total body water ratio in cardiovascular surgery patients. Clin Nutr. 2025;51:81\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBosy-Westphal A, Danielzik S, Dorhofer RP, Later W, Wiese S, Muller MJ. Phase angle from bioelectrical impedance analysis: population reference values by age, sex, and body mass index. JPEN J Parenter Enter Nutr. 2006;30(4):309\u0026ndash;16.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eFernandez-Jimenez R, Martin-Masot R, Cornejo-Pareja I, Vegas-Aguilar IM, Herrador-Lopez M, Tinahones FJ, et al. Phase angle as a marker of outcome in hospitalized pediatric patients. A systematic review of the evidence (GRADE) with meta-analysis. Rev Endocr Metab Disord. 2023;24(4):751\u0026ndash;65.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eColin-Ramirez E, Castillo-Martinez L, Orea-Tejeda A, Vazquez-Duran M, Rodriguez AE, Keirns-Davis C. Bioelectrical impedance phase angle as a prognostic marker in chronic heart failure. Nutrition. 2012;28(9):901\u0026ndash;5.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLukaski HC. Evolution of bioimpedance: a circuitous journey from estimation of physiological function to assessment of body composition and a return to clinical research. Eur J Clin Nutr. 2013;67(Suppl 1):S2\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAnker SD, Sharma R. The syndrome of cardiac cachexia. Int J Cardiol. 2002;85(1):51\u0026ndash;66.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMirzai S, Eck BL, Chen PH, Estep JD, Tang WHW. Current Approach to the Diagnosis of Sarcopenia in Heart Failure: A Narrative Review on the Role of Clinical and Imaging Assessments. Circ Heart Fail. 2022;15(10):e009322.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCamm AJ, Naccarelli GV, Mittal S, Crijns H, Hohnloser SH, Ma CS, et al. The Increasing Role of Rhythm Control in Patients With Atrial Fibrillation: JACC State-of-the-Art Review. J Am Coll Cardiol. 2022;79(19):1932\u0026ndash;48.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSchreiber T, Grune J, Landmesser U, Attanasio P. Detection and modification of biomarkers of inflammation determining successful rhythm control in patients with atrial fibrillation. Biomarkers. 2023;28(8):681\u0026ndash;91.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWabel P, Chamney P, Moissl U, Jirka T. Importance of whole-body bioimpedance spectroscopy for the management of fluid balance. Blood Purif. 2009;27(1):75\u0026ndash;80.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSchwenk A, Beisenherz A, Romer K, Kremer G, Salzberger B, Elia M. Phase angle from bioelectrical impedance analysis remains an independent predictive marker in HIV-infected patients in the era of highly active antiretroviral treatment. Am J Clin Nutr. 2000;72(2):496\u0026ndash;501.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eToso S, Piccoli A, Gusella M, Menon D, Bononi A, Crepaldi G, et al. Altered tissue electric properties in lung cancer patients as detected by bioelectric impedance vector analysis. Nutrition. 2000;16(2):120\u0026ndash;4.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMaggiore Q, Nigrelli S, Ciccarelli C, Grimaldi C, Rossi GA, Michelassi C. Nutritional and prognostic correlates of bioimpedance indexes in hemodialysis patients. Kidney Int. 1996;50(6):2103\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMattar JA. Application of total body bioimpedance to the critically ill patient. Brazilian Group for Bioimpedance Study. New Horiz. 1996;4(4):493\u0026ndash;503.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKorantzopoulos P, Letsas KP, Tse G, Fragakis N, Goudis CA, Liu T. Inflammation and atrial fibrillation: A comprehensive review. J Arrhythm. 2018;34(4):394\u0026ndash;401.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eda Silva TK, Berbigier MC, Rubin Bde A, Moraes RB, Correa Souza G, Schweigert Perry ID. Phase angle as a prognostic marker in patients with critical illness. Nutr Clin Pract. 2015;30(2):261\u0026ndash;5.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDisertori M, Quintarelli S. Renin-Angiotensin System and AtrialFibrillation:Understanding the Connection. J Atr Fibrillation. 2011;4(4):398.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChoi YY, Choi JI, Jeong JH, Lee HS, Kim YG, Kim MN, et al. Impact of pulmonary artery pressure on recurrence after catheter ablation in patients with atrial fibrillation. Front Cardiovasc Med. 2023;10:1187774.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAlmroth H, Karlsson LO, Carlhall CJ, Charitakis E. Haemodynamic changes after atrial fibrillation initiation in patients eligible for catheter ablation: a randomized controlled study. Eur Heart J Open. 2023;3(6):oead112.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"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":"Atrial Fibrillation, Catheter Ablation, Bioelectrical Impedance Analysis, Phase Angle, Overweight","lastPublishedDoi":"10.21203/rs.3.rs-7631336/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7631336/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e\u003cp\u003eThe phase angle (PhA), derived from bioelectrical impedance analysis (BIA), is an indicator of cellular health and nutritional status. Its role in patients with atrial fibrillation (AF), particularly after catheter ablation, is not well-established. This study aimed to investigate changes in PhA and their correlation with cardiac remodeling in overweight patients with persistent AF after cryoballoon ablation.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e\u003cp\u003eThirteen overweight patients (BMI\u0026thinsp;\u0026ge;\u0026thinsp;23 kg/m\u0026sup2;) with persistent AF scheduled for ablation were prospectively enrolled. Baseline clinical, echocardiographic, and BIA parameters were collected. At 6 months, follow-up data were available for 12 patients. AF recurrence was defined as any atrial tachyarrhythmia\u0026thinsp;\u0026ge;\u0026thinsp;30 seconds beyond a 3-month blanking period, confirmed by ECG or Holter monitoring.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e\u003cp\u003eFive patients experienced AF recurrence (PEF group), while eight maintained sinus rhythm (NSR group). Overall, no significant changes were observed in the total cohort. However, subgroup analysis demonstrated divergent changes in body composition. The NSR group showed significant improvements in intracellular water and phase angle values, whereas the PEF group exhibited consistent declines (p\u0026thinsp;\u0026lt;\u0026thinsp;0.05 for group comparisons).\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e\u003cp\u003eThese preliminary findings suggest that successful rhythm control after ablation may be associated with systemic recovery reflected by BIA-derived parameters. Larger, multicenter studies incorporating functional and clinical outcomes are warranted to validate the potential role of PhA as a biomarker for post-ablation recovery.\u003c/p\u003e\u003ch2\u003eTrial registration:\u003c/h2\u003e\u003cp\u003enot applicable\u003c/p\u003e","manuscriptTitle":"Exploratory Phase Angle Assessment After Atrial Fibrillation Ablation in Overweight Patients: A Pilot Study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-18 05:08:18","doi":"10.21203/rs.3.rs-7631336/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-12-18T05:43:58+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-12-16T10:42:08+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"249901899251530088108275728037366400695","date":"2025-12-09T02:07:51+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"318912706608676654951207580978903259225","date":"2025-12-08T15:26:00+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-11-25T03:42:02+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"222810917185857250275382877559256150469","date":"2025-11-24T22:32:00+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-10-06T02:10:31+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-09-23T06:51:49+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-09-22T06:25:00+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-09-22T06:23:51+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Cardiovascular Disorders","date":"2025-09-16T14:00:03+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":"78d3901b-44d8-4b22-8898-b02e2538e24a","owner":[],"postedDate":"October 18th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2026-02-16T16:04:47+00:00","versionOfRecord":{"articleIdentity":"rs-7631336","link":"https://doi.org/10.1186/s12872-026-05624-z","journal":{"identity":"bmc-cardiovascular-disorders","isVorOnly":false,"title":"BMC Cardiovascular Disorders"},"publishedOn":"2026-02-13 15:58:46","publishedOnDateReadable":"February 13th, 2026"},"versionCreatedAt":"2025-10-18 05:08:18","video":"","vorDoi":"10.1186/s12872-026-05624-z","vorDoiUrl":"https://doi.org/10.1186/s12872-026-05624-z","workflowStages":[]},"version":"v1","identity":"rs-7631336","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7631336","identity":"rs-7631336","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}