Transmission of 12-leads electrocardiogram from ambulances decreases patient complications of ST segment elevation myocardial infarction by reducing door-to-reperfusion time

Transmission of 12-leads electrocardiogram from ambulances decreases patient complications of ST segment elevation myocardial infarction by reducing door-to-reperfusion time | 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 Transmission of 12-leads electrocardiogram from ambulances decreases patient complications of ST segment elevation myocardial infarction by reducing door-to-reperfusion time Takeshi Suzuki, Akira Ito, Shinrou Saiki, Hirokazu Naganawa, Shinichi Takamatsu, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7521731/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background Recently, our hospital has obtained prehospital 12-lead electrocardiograms (ECGs) from ambulances. We examined the extent to which these 12-lead ECG transmissions shortened DTBT and improved prognosis. Methods From January 1, 2016, to August 14, 2025, 487 patients presented to our hospital within 12 hours after chest pain onset and were diagnosed with ST-segment elevation myocardial infarction. Among these cases, those who came in as walk-ins and those referred from local physicians were excluded from this study due to their different backgrounds and their prolonged total ischemia time. Patients were divided into two groups to compare the DTBT and subsequent outcomes: the group without ECG transmission and the group with ECG transmission. Major adverse events were defined as in-hospital or out-of-hospital death and heart failure following treatment, and data were collected. Results DTBT was significantly shorter in the ECG transmission group than in the no ECG transmission group, reflecting significantly shorter door-to-catheterization laboratory time (ECG transmission 44min, without transmission 66min, p < 0.01). Reflecting this, fewer major adverse cardiovascular events (MACE) were observed in the ECG transmission group than in the non-transmission group. Multivariate analysis showed that ECG transmission contributed to the achievement of DTBT within 60 minutes, and multivariate analysis showed that only Killip 2 degrees or greater significantly increased the incidence of MACE, but ECG transmission also tended to reduce it (Odds ratio 0.42, p = 0.05). Conclusions For patients who are aware of chest pain and present directly to the emergency department by ambulance, the 12-lead ECG transmission results obtained via this route may reduce patient complications. Prehospital ECG transmission ST segment elevation myocardial infarction Door-to-reperfusion time Total ischemic time Major adverse cardiac event Figures Figure 1 Introduction Primary percutaneous coronary intervention (PCI) plays a central role in the treatment of ST-segment elevation myocardial infarction (STEMI). [ 1 , 2 ] The American College of Cardiology/American Heart Association and European Society of Cardiology guidelines for STEMI recommend primary percutaneous coronary intervention within 90 minutes of first medical contact, or door-to-balloon time (DTBT), as a class 1 recommendation and a total ischemic time within 120 minutes. [ 3 , 4 ] The Japanese Circulation Society guidelines also recommend a total ischemic time of less than 120 minutes because complications are reduced when the total ischemic time was less than 120 minutes. [ 5 ] The J-MINUET database demonstrates that the shorter the DTBT, the better the clinical outcomes. [ 6 ] Imori et al. [ 7 ] suggested that not only DTBT, but also shortening the time between onset and hospital visit is important for improving prognosis. The transfer of prehospital electrocardiograms (ECGs) can improve in-hospital and remote-phase clinical outcomes by reducing DTBT. [ 8 ] In addition, Mori et al. [ 9 ] suggested that initial contact with a cardiologist, in addition to prehospital transfer of a 12-lead ECG, can shorten DTB. Since June 1, 2021, our hospital has been obtaining prehospital 12-lead ECGs from ambulances using a tablet PC or via e-mail. We examined the extent to which these 12-lead ECG transmissions shortened door-to-balloon time (DTBT) and improved prognosis. Methods Patients This was a single-center, retrospective study. In August 2019, our hospital began an experiment to deploy tablet PCs linked to our medical records in our city ambulances to capture 12-lead ECGs and transmit them to our medical records for patients with chest pain who required more than 5 minutes to arrive at our hospital. Since June 2021, all emergency medical technicians (EMTs) in the city have attempted to transmit ECGs using a tablet PC when they judged that the transport would take more than 5 minutes; EMTs outside the city have transmitted ECGs by e-mail when they agreed to our request, and 115 of the 157 cases (73%) transported to our hospital were transmitted. Since October 2022. As shown in Fig. 1 , 487 patients with STEMI within 12 h of onset were observed in our emergency department between January 2016 and August 14, 2025. Fifty-six patients were referred by their primary care physicians, but unlike the other cases, all of them had uncomplicated heart failure (Killip I), and the time from onset to presentation was longer than in the other direct-visit cases; therefore, they were omitted from this study. Nighty-seven patients arrived directly in our hospital in a private car and they were also omitted from this study because there was a tendency toward fewer cases of heart failure (> Killip I). A total of 337 patients arrived at our hospital via ambulance. ECG was not transmitted for 221 patients of the 337 patients. 116 patients had ECGs transmitted to our electronic medical records by a tablet PC from our city ambulances or through an e-mail from a nearby city ambulance (Fig. 1 ). When a 12-lead ECG was transmitted, it was immediately checked by the emergency room physician or cardiologist. If STEMI was diagnosed, an on-call cardiologist was notified and stood by before the ambulance arrived. We compared the DTBT, factors related to prognosis, and other factors to determine the effects of ECG transmission on patient outcomes and prognosis. Data collection Demographic and clinical data were collected from all patients who underwent primary PCI and were triaged in a catheterization laboratory (Cath Lab). Time data were collected at the onset of symptoms. Door-to-ECG time was defined as the time from hospital arrival to ECG evaluation. The door-to-catheter laboratory time was defined as the time between hospital arrival and entry into the catheterization laboratory. The door-to-angiography time was defined as the time between hospital arrival and the first imaging of the culprit lesion. Door to reperfusion time (DTR) was defined as the time between hospital arrival and the first intervention that restored patency of the culprit vessel, including angioplasty, stenting, or mechanical thrombectomy. Heart failure with Killip class II or higher and all-cause mortality were tabulated both inside and outside the hospital. Primary end point The primary endpoint was to compare DTR times for primary PCI using each ECG transmission method with the DTR times in patients with no ECG transmission. Other time intervals were also compared. Secondary end points The combined endpoint of heart failure and all-cause mortality was defined as a major adverse cardiac event (MACE). We compared MACEs between the ECG-transmitted and non-transmitted groups. Statistical analyse s Continuous variables were expressed as means ± standard deviation with normal or non-normal distributions. Continuous variables with a normal distribution were compared using the Student's t-test or ANOVA with Tukey’s test for independent samples. Categorical variables are expressed as frequencies and percentages and compared using the chi-square test or Fisher's exact test. Logistic regression analysis was used for multivariate analysis. The statistical analyses were performed using StatMate version 5 (Atms, Tokyo, Japan). Statistical significance was set at p < 0.05. Results A total of 337 patients excluded walk-ins and referrals from private physicians, with STEMI that came to our hospital underwent primary PCI for the culprit lesion. Of these patients, all patients came to the hospital by ambulance; 221 did not have ECG transmissions, and 116 patients’ ECGs were transmitted to our electronic medical records via a tablet PC from our city ambulance or e-mail from a nearby city ambulance. In the ECG transmission group, the increased use of DCBs reflected the recent increase in stentless procedures at our hospital. There were no significant differences among the two groups regarding other baseline or clinical backgrounds (Table 1 ). Table 1 Baseline characteristics Ambulance without ECG transmission (n = 221) Ambulance with ECG transmission (n = 116) P value Age (years) 69 ± 13 70 ± 13 0.38 Woman (%) 45(20%) 20(17%) 0.49 CKD (GFR < 30) 7(3.2%) 1(1.7%) 0.67 Hypertension 139(63%) 83(70%) 0.11 Dyslipidemia 141(64%) 75(65%) 0.88 Diabetes mellitus 78(35%) 41(35%) 0.99 Smoking 73(33%) 32(28%) 0.31 Previous myocardial infarction 13(5.9%) 7(6.0%) 0.96 Previous stroke 10(4.5%) 3(2.6%) 0.56 Onset to door time (hour) 1.7 ± 1.6 1.8 ± 1.5 0.57 Killip Class > I 55(25%) 26(22%) 0.61 Target vessels 0.39 Left main trunk 7(3.2%) 2(1.7%) Right coronary artery 81(37%) 46(40%) Left anterior descending artery 118(53%) 55(47%) Left circumflex artery 15(6.8%) 13(11%) Use of IABP 34(15%) 14(12%) 0.41 Use of PCPS 8(3.6%) 5(4.3%) 0.75 Final device for treatment 0.02 Drug eluting stent 182(82%) 88(76%) Drug coating balloon 15(6.8%) 20(17%) Plain old balloon angioplasty 22(10%) 8(6.9%) Thrombectomy only 2(0.9%) 0 Use of filter wire 150(68%) 76(66%) 0.66 Combination of thrombus aspiration 88(40%) 48(41%) 0.78 QCA pretreatment Reference diameter (mm) 2.75 ± 0.65 2.72 ± 0.57 0.71 MLD (mm) 0.31 ± 0.43 0.25 ± 0.36 0.20 Lesion length (mm) 18.5 ± 12.2 16.8 ± 7.9 0.16 Post treatment MLD (mm) 2.48 ± 0.57 2.53 ± 0.59 0.43 % Diameter stenosis 18.5 ± 12.1 20.2 ± 11.3 0.19 Continuous values are shown as mean ± standard deviation; categorical data are indicated as number (%) CKD, chronic kidney disease; ECG, electrocardiography; GFR, glomerular filtration rate; IABP, intra-aortic balloon pump; MLD, minimum lesion diameter; PCPS, percutaneous cardiopulmonary support; QCA, quantitative coronary angiography. Time comparisons between the two groups are presented in Table 2 . The ECG transmission group had significantly shorter DTR of 22 min than the ECG non-transmission group, reflecting shorter transport times from hospital arrival to the catheterization laboratory. Reflecting these factors, the total ischemic time was shorter for the ambulance with ECG transmission group than the ECG non-transmission group. The procedure time was same between the two groups. Table 2 Time course comparison between the two groups Ambulance without ECG transmission (n = 221) Ambulance with ECG transmission (n = 116) p value Door to ECG time (minute) 3.4 ± 7.0 0.1 ± 0.4 < 0.01 Door to cath lab time (minute) 36.8 ± 30.9 16.2 ± 12.1 < 0.01 Door to angiography time (minute) 53.7 ± 32.1 34.7 ± 13.0 < 0.01 Door to reperfusion time (minute) 66.3 ± 38.4 43.9 ± 16.6 < 0.01 Procedure time (minute) 95 ± 42 89 ± 37 0.21 Total ischemic time (minute) 166 ± 110 150 ± 94 0.18 Continuous values are shown as mean ± standard deviation ECG, electrocardiogram. The prognostic factors were examined among the four groups (Table 3 ). The ambulance without ECG transmission group had more MACE, even though there were no differences in background among the two groups. Factors associated with MACE were examined using multivariate analysis (Table 4 ). Only the Killip class significantly increased MACE; ECG transmission also showed a trend toward decreased MACE. As the median DTR for an ambulance visit at our hospital is approximately 60 min, Table 5 shows the multivariate analysis of the factors involved in a DTR of 60 min or less. ECG transmission was a strong DTR-shortening factor, and lesion lengths greater than 20 mm prevented the achievement of DTR within 60 min. These results suggest that the transmission of ECGs from ambulances to our hospital may improve the prognosis by shortening the DTR. Table 3 Prognostic factors between the two groups Ambulance without ECG transmission (n = 221) Ambulance with ECG transmission (n = 116) p value LVEF after PCI(%) 55.7 ± 12.3 (n = 190) 56.4 ± 10.8 (n = 101) 0.66 Max CPK (IU/l) 3005 ± 3275 2783 ± 2301 0.52 Heart failure in hospital 27(12%) 10(9%) 0.32 Heart failure after discharge 6(3%) 1(1%) 0.46 All cause death in hospital 14(6%) 4(4%) 0.39 All cause death after discharge 5(2%) 1(1%) 0.62 TLR 14(6%) 4(4%) 0.39 MACE 38(17%) 10(9%) 0.03 Continuous values are shown as mean ± standard deviation, TLR, target lesion revascularization MACE, major adverse event (Heart failure + death) Table 4 Multivariable predictors of MACE P value Odds ratio(95%CI) Killip class < 0.00001 17.8(2.12–3.65) DTR 0.14243 1.007(-0.002–0.016) ECG transmission 0.05469 0.42(-1.764–0.018) DTR, door-to-reperfusion time; ECG, electrocardiogram; MACE, major adverse event (combination of heart failure and death). Adjusted OR and 95% CI indicate the likelihood of MACE from logistic regression. Table 5 Multivariable predictors of a DTR of 60 minutes or less P value Odds ratio(95%CI) ECG transmission 20mm) 0.032242 0.54(-1.17 - -0.52) Night time arrival* 0.106678 0.64(-0.98–0.09) Flection of the lesion (> 90°) 0.670686 1.19 (-0.62–0.97) DTR, door to reperfusion time; *between 22 o’clock and 6 o’clock. Discussion A short DTR and total ischemic time have been shown to lead to a better prognosis. [ 5 , 6 ] The transfer of prehospital ECGs can improve in-hospital and remote-phase clinical outcomes by reducing the DTBT. [ 7 ] Mori et al. [ 8 ] reported that initial contact with a cardiologist in addition to prehospital 12-lead ECG transmission led to faster DTR and better prognosis. In this ECG transmission study, the first contact was with the emergency room physician. However, once ST elevation was confirmed, the cardiologist was immediately contacted, resulting in a faster DTR and better prognosis. Beygui et al. [ 10 ] reported that compared to directly admitted patients, those indirectly transferred were significantly older, more likely to be women, had a Killip class ≥ I, and had diabetes. The number of patients with a first medical contact-to-balloon time of < 120 min was three times lower than that of patients who were indirectly transferred. At one-year follow-up, 51 (14.6%) and 137 (7.7%) patients died in the indirect and direct admission groups, respectively (adjusted hazard ratio; 1.73, 95% confidence interval; 1.22–2.45). In our study, there was no similar trend, and there were a few Killip grade ≥ II direct-visit cases. In our study, there was no difference in prognosis between the direct- and ambulance visit cases, which may have contributed to these results. In our town, patients with more severe cases were more likely to use an ambulance, which may be the correct direction for patients with STEMI. Conclusions The ECG transmission group had a reduced DTR time of approximately 20 min and they also had reduced total ischemic time. It also showed that the shortening of DTR due to ECG transmission may have further contributed to the reduction of MACEs (heart failure and death). In cases involving direct transportation to the hospital in this study, transmitting 12-lead ECGs was recommended to reduce complications by shortening the DTR, regardless of the transmission method. Further large-scale studies are required to confirm these findings. Abbreviations ECG electrocardiogram MACE major adverse cardiovascular events PCI Primary percutaneous coronary intervention STEMI ST-segment elevation myocardial infarction DTBT door-to-balloon time EMTs emergency medical technicians DTR Door to reperfusion time Declarations Ethics Approval and consent to participate All participants provided written consent before entering the study. This study was approved by the Ethics Committee of our institution on June 5, 2024. The approval number for 2024 is 226. Conflicts of Interest All authors declare no conflicts of interest. Clinical trial number not applicable. Consent for publication Not Applicable. Funding Not Applicable. Author Contribution All authors contributed to the conception and design of this study. Takashi Matsumoto was instrumental in purchasing iPads linked to the electronic medical records of our town’s ambulances. Takeshi Suzuki conceived the idea for this study and wrote the manuscript. All the authors have read and approved the final version of the manuscript. Acknowledgement The authors thank the members of the cardiac catheterization laboratory and emergency room at our hospital, as well as the emergency medical technicians in our district. We would also like to thank Honyaku Center Inc. for their assistance with English language editing. Data Availability Data is provided within the manuscript files. References Gibson CM, Pride YB, Frederick PD, Pollack CV, Canto JG, Tiefenbrunn AJ, et al. Trends in reperfusion strategies, door-to-needle and door-to-balloon times, and in-hospital mortality among patients with ST-segment elevation myocardial infarction enrolled in the national registry of myocardial infarction from 1990 to 2006. Am Heart J. 2008;156:1035–44. 10.1016/j.ahj.2008.07.029 . Eagle KA, Nallamothu BK, Mehta RH, Granger CB, Steg PG, Van de Werf F, et al. Trends in acute reperfusion therapy for ST-segment elevation myocardial infarction from 1999 to 2006: We are getting better but we have got a long way to go. Eur Heart J. 2008;29:609–17. 10.1093/eurheartj/ehn069 . Ibanez B, James S, Agewall S, Antunes MJ, Bucciarelli-Ducci C, Bueno H, et al. ESC Guidelines for the management of acute myocardial infarction in patients presenting with ST-segment elevation. Eur Heart J. 2018;39:119–77. 10.1093/eurheartj/ehx393 . O’gara PT, Kushner FG, Ascheim DD, Casey DD Jr, Chung MK, deLemos JA, et al. 2013 ACCF/AHA guideline for the management of ST-elevation myocardial infarction: A report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol. 2013;61:e78–140. 10.1016/j.jacc.2012.11.019 . Kimura K, Kimura T, Ishihara M, Nakagawa Y, Nakao K, Miyauchi K, et al. JCS 2018 guideline on diagnosis and treatment of acute coronary syndrome. Circ J. 2019;83:1085–196. 10.1253/circj.CJ-19-0133 . Nishio R, Ogita M, Suwa S, Nakao K, Ozaki Y, Kimura K, et al. Shorter door-to-balloon time, better long-term clinical outcomes in ST-segment elevation myocardial infarction patients: J-MINUET substudy. J Cardiol. 2023;81:564–70. 10.1016/j.jjcc.2023.01.008 . Imori Y, Akasaka T, Shishido K, Ochiai T, Tobita K, Yamanaka F, et al. Prehospital transfer pathway and mortality in patients undergoing primary percutaneous coronary intervention. Circ J. 2015;79:2000–8. Welsford M, Nikolaou NI, Beygui F, Bossaert L, Ghaemmaghami C, Nonogi H, et al. Acute coronary syndromes 2015 international consensus on cardiopulmonary resuscitation and emergency cardiovascular care science with treatment recommendations. Circulation. 2015;132(Suppl 1):S146–76. 10.1161/CIR.0000000000000274 . Mori H, Maeda A, Akashi Y, Ako J, Ikari Y, Ebina T, et al. The impact of pre-hospital 12-lead electrocardiogram and first contact by cardiologist in patients with ST-elevation myocardial infarction in Kanagawa, Japan. J Cardiol. 2021;78:183–92. 10.1016/j.jjcc.2021.04.001 . Yoshioka Y, Teshima R, Gamo M, Yoneda R, Matsunaga N, Takada T, et al. A physician-staffed ground emergency medical service does not significantly shorten door-to-balloon time in patients with STEMI: An observational study in a single emergency center in Japan. Acute Med Surg. 2020;7:e542. 10.1002/ams2.542 . Beygui F, Roule V, Ivanes F, Dechery T, Bizeau O, Roussel L, et al. Indirect transfer to catheterization laboratory for ST elevation myocardial infarction is associated with mortality independent of system delays: Insights from the France-PCI registry. Front Cardiovasc Med. 2022;9:793067. 10.3389/fcvm.2022.793067 . Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted 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. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7521731","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":517147838,"identity":"5c9e3870-9ede-47ab-8ae0-70adb742cdbf","order_by":0,"name":"Takeshi 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time","fulltext":[{"header":"Introduction","content":"\u003cp\u003ePrimary percutaneous coronary intervention (PCI) plays a central role in the treatment of ST-segment elevation myocardial infarction (STEMI). [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e] The American College of Cardiology/American Heart Association and European Society of Cardiology guidelines for STEMI recommend primary percutaneous coronary intervention within 90 minutes of first medical contact, or door-to-balloon time (DTBT), as a class 1 recommendation and a total ischemic time within 120 minutes. [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]\u003csup\u003e \u003c/sup\u003eThe Japanese Circulation Society guidelines also recommend a total ischemic time of less than 120 minutes because complications are reduced when the total ischemic time was less than 120 minutes. [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e] The J-MINUET database demonstrates that the shorter the DTBT, the better the clinical outcomes. [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e] Imori et al. [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e] suggested that not only DTBT, but also shortening the time between onset and hospital visit is important for improving prognosis. The transfer of prehospital electrocardiograms (ECGs) can improve in-hospital and remote-phase clinical outcomes by reducing DTBT. [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e8\u003c/span\u003e] In addition, Mori et al. [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e9\u003c/span\u003e] suggested that initial contact with a cardiologist, in addition to prehospital transfer of a 12-lead ECG, can shorten DTB. Since June 1, 2021, our hospital has been obtaining prehospital 12-lead ECGs from ambulances using a tablet PC or via e-mail. We examined the extent to which these 12-lead ECG transmissions shortened door-to-balloon time (DTBT) and improved prognosis.\u003c/p\u003e"},{"header":"Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003ePatients\u003c/h2\u003e\u003cp\u003eThis was a single-center, retrospective study. In August 2019, our hospital began an experiment to deploy tablet PCs linked to our medical records in our city ambulances to capture 12-lead ECGs and transmit them to our medical records for patients with chest pain who required more than 5 minutes to arrive at our hospital. Since June 2021, all emergency medical technicians (EMTs) in the city have attempted to transmit ECGs using a tablet PC when they judged that the transport would take more than 5 minutes; EMTs outside the city have transmitted ECGs by e-mail when they agreed to our request, and 115 of the 157 cases (73%) transported to our hospital were transmitted. Since October 2022. As shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e, 487 patients with STEMI within 12 h of onset were observed in our emergency department between January 2016 and August 14, 2025. Fifty-six patients were referred by their primary care physicians, but unlike the other cases, all of them had uncomplicated heart failure (Killip I), and the time from onset to presentation was longer than in the other direct-visit cases; therefore, they were omitted from this study. Nighty-seven patients arrived directly in our hospital in a private car and they were also omitted from this study because there was a tendency toward fewer cases of heart failure (\u0026gt;\u0026thinsp;Killip I). A total of 337 patients arrived at our hospital via ambulance. ECG was not transmitted for 221 patients of the 337 patients. 116 patients had ECGs transmitted to our electronic medical records by a tablet PC from our city ambulances or through an e-mail from a nearby city ambulance (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). When a 12-lead ECG was transmitted, it was immediately checked by the emergency room physician or cardiologist. If STEMI was diagnosed, an on-call cardiologist was notified and stood by before the ambulance arrived. We compared the DTBT, factors related to prognosis, and other factors to determine the effects of ECG transmission on patient outcomes and prognosis.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003eData collection\u003c/h3\u003e\n\u003cp\u003eDemographic and clinical data were collected from all patients who underwent primary PCI and were triaged in a catheterization laboratory (Cath Lab). Time data were collected at the onset of symptoms. Door-to-ECG time was defined as the time from hospital arrival to ECG evaluation. The door-to-catheter laboratory time was defined as the time between hospital arrival and entry into the catheterization laboratory. The door-to-angiography time was defined as the time between hospital arrival and the first imaging of the culprit lesion. Door to reperfusion time (DTR) was defined as the time between hospital arrival and the first intervention that restored patency of the culprit vessel, including angioplasty, stenting, or mechanical thrombectomy. Heart failure with Killip class II or higher and all-cause mortality were tabulated both inside and outside the hospital.\u003c/p\u003e\n\u003ch3\u003ePrimary end point\u003c/h3\u003e\n\u003cp\u003eThe primary endpoint was to compare DTR times for primary PCI using each ECG transmission method with the DTR times in patients with no ECG transmission. Other time intervals were also compared.\u003c/p\u003e\n\u003ch3\u003eSecondary end points\u003c/h3\u003e\n\u003cp\u003eThe combined endpoint of heart failure and all-cause mortality was defined as a major adverse cardiac event (MACE). We compared MACEs between the ECG-transmitted and non-transmitted groups.\u003c/p\u003e\u003cp\u003e\u003cb\u003eStatistical analyse\u003c/b\u003e\u003cb\u003es\u003c/b\u003e\u003c/p\u003e\u003cp\u003eContinuous variables were expressed as means\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation with normal or non-normal distributions. Continuous variables with a normal distribution were compared using the Student's t-test or ANOVA with Tukey\u0026rsquo;s test for independent samples. Categorical variables are expressed as frequencies and percentages and compared using the chi-square test or Fisher's exact test. Logistic regression analysis was used for multivariate analysis.\u003c/p\u003e\u003cp\u003eThe statistical analyses were performed using StatMate version 5 (Atms, Tokyo, Japan). Statistical significance was set at p\u0026thinsp;\u0026lt;\u0026thinsp;0.05.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eA total of 337 patients excluded walk-ins and referrals from private physicians, with STEMI that came to our hospital underwent primary PCI for the culprit lesion. Of these patients, all patients came to the hospital by ambulance; 221 did not have ECG transmissions, and 116 patients\u0026rsquo; ECGs were transmitted to our electronic medical records via a tablet PC from our city ambulance or e-mail from a nearby city ambulance. In the ECG transmission group, the increased use of DCBs reflected the recent increase in stentless procedures at our hospital. There were no significant differences among the two groups regarding other baseline or clinical backgrounds (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\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\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eAmbulance without ECG transmission\u003c/p\u003e\u003cp\u003e(n\u0026thinsp;=\u0026thinsp;221)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eAmbulance with ECG transmission\u003c/p\u003e\u003cp\u003e(n\u0026thinsp;=\u0026thinsp;116)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eP value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAge (years)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e69\u0026thinsp;\u0026plusmn;\u0026thinsp;13\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e70\u0026thinsp;\u0026plusmn;\u0026thinsp;13\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.38\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eWoman (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e45(20%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e20(17%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.49\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCKD (GFR\u0026thinsp;\u0026lt;\u0026thinsp;30)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e7(3.2%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1(1.7%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.67\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHypertension\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e139(63%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e83(70%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.11\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDyslipidemia\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e141(64%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e75(65%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.88\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDiabetes mellitus\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e78(35%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e41(35%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.99\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSmoking\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e73(33%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e32(28%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.31\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePrevious myocardial infarction\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e13(5.9%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e7(6.0%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.96\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePrevious stroke\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e10(4.5%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3(2.6%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.56\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eOnset to door time (hour)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.7\u0026thinsp;\u0026plusmn;\u0026thinsp;1.6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.8\u0026thinsp;\u0026plusmn;\u0026thinsp;1.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.57\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eKillip Class\u0026thinsp;\u0026gt;\u0026thinsp;I\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e55(25%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e26(22%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.61\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTarget vessels\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.39\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLeft main trunk\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e7(3.2%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2(1.7%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRight coronary artery\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e81(37%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e46(40%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLeft anterior descending artery\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e118(53%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e55(47%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLeft circumflex artery\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e15(6.8%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e13(11%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eUse of IABP\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e34(15%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e14(12%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.41\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eUse of PCPS\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e8(3.6%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e5(4.3%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.75\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFinal device for treatment\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.02\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDrug eluting stent\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e182(82%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e88(76%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDrug coating balloon\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e15(6.8%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e20(17%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePlain old balloon angioplasty\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e22(10%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e8(6.9%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eThrombectomy only\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2(0.9%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eUse of filter wire\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e150(68%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e76(66%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.66\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCombination of thrombus aspiration\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e88(40%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e48(41%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.78\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eQCA\u003c/p\u003e\u003cp\u003epretreatment\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eReference diameter (mm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2.75\u0026thinsp;\u0026plusmn;\u0026thinsp;0.65\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2.72\u0026thinsp;\u0026plusmn;\u0026thinsp;0.57\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.71\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMLD (mm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.31\u0026thinsp;\u0026plusmn;\u0026thinsp;0.43\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.25\u0026thinsp;\u0026plusmn;\u0026thinsp;0.36\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.20\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLesion length (mm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e18.5\u0026thinsp;\u0026plusmn;\u0026thinsp;12.2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e16.8\u0026thinsp;\u0026plusmn;\u0026thinsp;7.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.16\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePost treatment\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMLD (mm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2.48\u0026thinsp;\u0026plusmn;\u0026thinsp;0.57\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2.53\u0026thinsp;\u0026plusmn;\u0026thinsp;0.59\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.43\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e% Diameter stenosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e18.5\u0026thinsp;\u0026plusmn;\u0026thinsp;12.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e20.2\u0026thinsp;\u0026plusmn;\u0026thinsp;11.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.19\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003eContinuous values are shown as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation; categorical data are indicated as number (%)\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003eCKD, chronic kidney disease; ECG, electrocardiography; GFR, glomerular filtration rate; IABP, intra-aortic balloon pump; MLD, minimum lesion diameter; PCPS, percutaneous cardiopulmonary support; QCA, quantitative coronary angiography.\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eTime comparisons between the two groups are presented in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. The ECG transmission group had significantly shorter DTR of 22 min than the ECG non-transmission group, reflecting shorter transport times from hospital arrival to the catheterization laboratory. Reflecting these factors, the total ischemic time was shorter for the ambulance with ECG transmission group than the ECG non-transmission group. The procedure time was same between the two 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\u003eTime course comparison between the two groups\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eAmbulance without ECG transmission\u003c/p\u003e\u003cp\u003e(n\u0026thinsp;=\u0026thinsp;221)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eAmbulance with ECG transmission\u003c/p\u003e\u003cp\u003e(n\u0026thinsp;=\u0026thinsp;116)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\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\u003eDoor to ECG time (minute)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e3.4\u0026thinsp;\u0026plusmn;\u0026thinsp;7.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e0.1\u0026thinsp;\u0026plusmn;\u0026thinsp;0.4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.01\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDoor to cath lab time (minute)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e36.8\u0026thinsp;\u0026plusmn;\u0026thinsp;30.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e16.2\u0026thinsp;\u0026plusmn;\u0026thinsp;12.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.01\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDoor to angiography time (minute)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e53.7\u0026thinsp;\u0026plusmn;\u0026thinsp;32.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e34.7\u0026thinsp;\u0026plusmn;\u0026thinsp;13.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.01\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDoor to reperfusion time (minute)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e66.3\u0026thinsp;\u0026plusmn;\u0026thinsp;38.4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e43.9\u0026thinsp;\u0026plusmn;\u0026thinsp;16.6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.01\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eProcedure time (minute)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e95\u0026thinsp;\u0026plusmn;\u0026thinsp;42\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e89\u0026thinsp;\u0026plusmn;\u0026thinsp;37\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.21\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTotal ischemic time (minute)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e166\u0026thinsp;\u0026plusmn;\u0026thinsp;110\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e150\u0026thinsp;\u0026plusmn;\u0026thinsp;94\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.18\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003eContinuous values are shown as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003eECG, electrocardiogram.\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eThe prognostic factors were examined among the four groups (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). The ambulance without ECG transmission group had more MACE, even though there were no differences in background among the two groups. Factors associated with MACE were examined using multivariate analysis (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). Only the Killip class significantly increased MACE; ECG transmission also showed a trend toward decreased MACE. As the median DTR for an ambulance visit at our hospital is approximately 60 min, Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e shows the multivariate analysis of the factors involved in a DTR of 60 min or less. ECG transmission was a strong DTR-shortening factor, and lesion lengths greater than 20 mm prevented the achievement of DTR within 60 min. These results suggest that the transmission of ECGs from ambulances to our hospital may improve the prognosis by shortening the DTR.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003ePrognostic factors between the two groups\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eAmbulance without ECG transmission\u003c/p\u003e\u003cp\u003e(n\u0026thinsp;=\u0026thinsp;221)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eAmbulance with ECG transmission\u003c/p\u003e\u003cp\u003e(n\u0026thinsp;=\u0026thinsp;116)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\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\u003eLVEF after PCI(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e55.7\u0026thinsp;\u0026plusmn;\u0026thinsp;12.3 (n\u0026thinsp;=\u0026thinsp;190)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e56.4\u0026thinsp;\u0026plusmn;\u0026thinsp;10.8 (n\u0026thinsp;=\u0026thinsp;101)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.66\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMax CPK (IU/l)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3005\u0026thinsp;\u0026plusmn;\u0026thinsp;3275\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2783\u0026thinsp;\u0026plusmn;\u0026thinsp;2301\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.52\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHeart failure in hospital\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e27(12%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e10(9%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.32\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHeart failure after discharge\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e6(3%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1(1%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.46\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAll cause death in hospital\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e14(6%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4(4%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.39\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAll cause death after discharge\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5(2%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1(1%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.62\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTLR\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e14(6%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4(4%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.39\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMACE\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e38(17%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e10(9%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.03\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003eContinuous values are shown as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation,\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003eTLR, target lesion revascularization\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003eMACE, major adverse event (Heart failure\u0026thinsp;+\u0026thinsp;death)\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eMultivariable predictors of MACE\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"3\"\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=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eP value\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eOdds ratio(95%CI)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eKillip class\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.00001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e17.8(2.12\u0026ndash;3.65)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDTR\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.14243\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e1.007(-0.002\u0026ndash;0.016)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eECG transmission\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.05469\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.42(-1.764\u0026ndash;0.018)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"3\"\u003eDTR, door-to-reperfusion time; ECG, electrocardiogram; MACE, major adverse event (combination of heart failure and death). Adjusted OR and 95% CI indicate the likelihood of MACE from logistic regression.\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eMultivariable predictors of a DTR of 60 minutes or less\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"3\"\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=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eP value\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eOdds ratio(95%CI)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eECG transmission\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.00001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e5.54(1.08\u0026ndash;2.34)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLesion length(\u0026gt;\u0026thinsp;20mm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.032242\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.54(-1.17 - -0.52)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNight time arrival*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.106678\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.64(-0.98\u0026ndash;0.09)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFlection of the lesion (\u0026gt;\u0026thinsp;90\u0026deg;)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.670686\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e1.19 (-0.62\u0026ndash;0.97)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"3\"\u003eDTR, door to reperfusion time; *between 22 o\u0026rsquo;clock and 6 o\u0026rsquo;clock.\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eA short DTR and total ischemic time have been shown to lead to a better prognosis. [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e] The transfer of prehospital ECGs can improve in-hospital and remote-phase clinical outcomes by reducing the DTBT. [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e] Mori et al. [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e8\u003c/span\u003e] reported that initial contact with a cardiologist in addition to prehospital 12-lead ECG transmission led to faster DTR and better prognosis. In this ECG transmission study, the first contact was with the emergency room physician. However, once ST elevation was confirmed, the cardiologist was immediately contacted, resulting in a faster DTR and better prognosis.\u003c/p\u003e\u003cp\u003eBeygui et al. [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e10\u003c/span\u003e] reported that compared to directly admitted patients, those indirectly transferred were significantly older, more likely to be women, had a Killip class\u0026thinsp;\u0026ge;\u0026thinsp;I, and had diabetes. The number of patients with a first medical contact-to-balloon time of \u0026lt;\u0026thinsp;120 min was three times lower than that of patients who were indirectly transferred. At one-year follow-up, 51 (14.6%) and 137 (7.7%) patients died in the indirect and direct admission groups, respectively (adjusted hazard ratio; 1.73, 95% confidence interval; 1.22\u0026ndash;2.45). In our study, there was no similar trend, and there were a few Killip grade\u0026thinsp;\u0026ge;\u0026thinsp;II direct-visit cases. In our study, there was no difference in prognosis between the direct- and ambulance visit cases, which may have contributed to these results. In our town, patients with more severe cases were more likely to use an ambulance, which may be the correct direction for patients with STEMI.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eThe ECG transmission group had a reduced DTR time of approximately 20 min and they also had reduced total ischemic time. It also showed that the shortening of DTR due to ECG transmission may have further contributed to the reduction of MACEs (heart failure and death). In cases involving direct transportation to the hospital in this study, transmitting 12-lead ECGs was recommended to reduce complications by shortening the DTR, regardless of the transmission method. Further large-scale studies are required to confirm these findings.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eECG electrocardiogram\u003c/p\u003e\u003cp\u003eMACE major adverse cardiovascular events\u003c/p\u003e\u003cp\u003ePCI Primary percutaneous coronary intervention\u003c/p\u003e\u003cp\u003eSTEMI ST-segment elevation myocardial infarction\u003c/p\u003e\u003cp\u003eDTBT door-to-balloon time\u003c/p\u003e\u003cp\u003eEMTs emergency medical technicians\u003c/p\u003e\u003cp\u003eDTR Door to reperfusion time\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eEthics Approval and consent to participate\u003c/h2\u003e\u003cp\u003e All participants provided written consent before entering the study. This study was approved by the Ethics Committee of our institution on June 5, 2024. The approval number for 2024 is 226.\u003c/p\u003e\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eConflicts of Interest\u003c/strong\u003e\u003cp\u003eAll authors declare no conflicts of interest.\u003c/p\u003e\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eClinical trial number\u003c/strong\u003e\u003cp\u003enot applicable.\u003c/p\u003e\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\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\u003eAll authors contributed to the conception and design of this study. Takashi Matsumoto was instrumental in purchasing iPads linked to the electronic medical records of our town\u0026rsquo;s ambulances. Takeshi Suzuki conceived the idea for this study and wrote the manuscript. All the authors have read and approved the final version of the manuscript.\u003c/p\u003e\u003ch2\u003eAcknowledgement\u003c/h2\u003e\u003cp\u003eThe authors thank the members of the cardiac catheterization laboratory and emergency room at our hospital, as well as the emergency medical technicians in our district. We would also like to thank Honyaku Center Inc. for their assistance with English language editing.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003e Data is provided within the manuscript files.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eGibson CM, Pride YB, Frederick PD, Pollack CV, Canto JG, Tiefenbrunn AJ, et al. Trends in reperfusion strategies, door-to-needle and door-to-balloon times, and in-hospital mortality among patients with ST-segment elevation myocardial infarction enrolled in the national registry of myocardial infarction from 1990 to 2006. 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Acute coronary syndromes 2015 international consensus on cardiopulmonary resuscitation and emergency cardiovascular care science with treatment recommendations. Circulation. 2015;132(Suppl 1):S146\u0026ndash;76. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1161/CIR.0000000000000274\u003c/span\u003e\u003cspan address=\"10.1161/CIR.0000000000000274\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMori H, Maeda A, Akashi Y, Ako J, Ikari Y, Ebina T, et al. The impact of pre-hospital 12-lead electrocardiogram and first contact by cardiologist in patients with ST-elevation myocardial infarction in Kanagawa, Japan. 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Indirect transfer to catheterization laboratory for ST elevation myocardial infarction is associated with mortality independent of system delays: Insights from the France-PCI registry. Front Cardiovasc Med. 2022;9:793067. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3389/fcvm.2022.793067\u003c/span\u003e\u003cspan address=\"10.3389/fcvm.2022.793067\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Prehospital ECG transmission, ST segment elevation myocardial infarction, Door-to-reperfusion time, Total ischemic time, Major adverse cardiac event","lastPublishedDoi":"10.21203/rs.3.rs-7521731/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7521731/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e\u003cp\u003eRecently, our hospital has obtained prehospital 12-lead electrocardiograms (ECGs) from ambulances. We examined the extent to which these 12-lead ECG transmissions shortened DTBT and improved prognosis.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e\u003cp\u003eFrom January 1, 2016, to August 14, 2025, 487 patients presented to our hospital within 12 hours after chest pain onset and were diagnosed with ST-segment elevation myocardial infarction. Among these cases, those who came in as walk-ins and those referred from local physicians were excluded from this study due to their different backgrounds and their prolonged total ischemia time. Patients were divided into two groups to compare the DTBT and subsequent outcomes: the group without ECG transmission and the group with ECG transmission. Major adverse events were defined as in-hospital or out-of-hospital death and heart failure following treatment, and data were collected.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e\u003cp\u003eDTBT was significantly shorter in the ECG transmission group than in the no ECG transmission group, reflecting significantly shorter door-to-catheterization laboratory time (ECG transmission 44min, without transmission 66min, p\u0026thinsp;\u0026lt;\u0026thinsp;0.01). Reflecting this, fewer major adverse cardiovascular events (MACE) were observed in the ECG transmission group than in the non-transmission group. Multivariate analysis showed that ECG transmission contributed to the achievement of DTBT within 60 minutes, and multivariate analysis showed that only Killip 2 degrees or greater significantly increased the incidence of MACE, but ECG transmission also tended to reduce it (Odds ratio 0.42, p\u0026thinsp;=\u0026thinsp;0.05).\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e\u003cp\u003eFor patients who are aware of chest pain and present directly to the emergency department by ambulance, the 12-lead ECG transmission results obtained via this route may reduce patient complications.\u003c/p\u003e","manuscriptTitle":"Transmission of 12-leads electrocardiogram from ambulances decreases patient complications of ST segment elevation myocardial infarction by reducing door-to-reperfusion time","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-09-23 15:47:30","doi":"10.21203/rs.3.rs-7521731/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"7aa60fee-cf48-4c2d-9a5d-14429e5b4465","owner":[],"postedDate":"September 23rd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-10-06T08:09:25+00:00","versionOfRecord":[],"versionCreatedAt":"2025-09-23 15:47:30","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7521731","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7521731","identity":"rs-7521731","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}