Achieving Door-to-Balloon Time ≤90 Minutes in ST-Elevation Myocardial Infarction (STEMI): Results of a Retrospective Audit

Achieving Door-to-Balloon Time ≤90 Minutes in ST-Elevation Myocardial Infarction (STEMI): Results of a Retrospective Audit | 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 Achieving Door-to-Balloon Time ≤90 Minutes in ST-Elevation Myocardial Infarction (STEMI): Results of a Retrospective Audit Rajarajeswaran Krishnan, C. M. Dhileeban, Hariprasad S, Ameen Umer P, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7559914/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 17 Apr, 2026 Read the published version in International Journal of Emergency Medicine → Version 1 posted 39 You are reading this latest preprint version Abstract Background Timely reperfusion therapy with primary percutaneous coronary intervention (PCI) significantly improves outcomes in ST-elevation myocardial infarction (STEMI). Current international guidelines recommend achieving a door-to-balloon (D2B) time of ≤ 90 minutes in at least 90% of eligible patients. This audit aimed to evaluate institutional adherence to this benchmark at a tertiary care center in India. Methods A retrospective clinical audit was conducted at SRM Medical College Hospital and Research Centre over a 12-month period (January–December 2024). All adult STEMI patients who underwent primary PCI were included. Patients treated with thrombolysis or with non-system-related delays were excluded. Key time points, including emergency department (ED) arrival, ECG, PCI decision, and balloon inflation, were analyzed. The primary outcome was the percentage of patients achieving D2B time ≤ 90 minutes. Results Among 657 STEMI patients presenting to the ED, 620 (94.4%) were taken for primary PCI. Of these, 564 patients (91.0%) achieved a D2B time within 90 minutes, meeting the international benchmark. Delays beyond 90 minutes were noted in 56 patients (9.0%), primarily due to delayed consent (37.5%), need for medical stabilization (32.1%), and diagnostic ambiguity (30.4%). Conclusion The audit confirmed that coordinated STEMI care at our center achieved the international D2B benchmark in 91% of eligible patients. However, system and patient-level delays remain a challenge. Interventions such as rapid consent pathways, enhanced triage protocols, and continuous team training are recommended to further reduce treatment delays and optimize patient outcomes. STEMI door-to-balloon time primary PCI clinical audit emergency cardiology reperfusion delay India Figures Figure 1 INTRODUCTION ST-elevation myocardial infarction (STEMI) is one of the most critical cardiovascular emergencies, necessitating immediate medical intervention to restore myocardial perfusion and prevent irreversible ischemic damage. The principle of “ time is muscle ” underscores the urgency in treating these patients: for every minute of delay in reperfusion therapy, a significant number of myocardial cells are lost, contributing to deterioration in morbidity and increased mortality [ 1 ]. Among the available treatment options, primary percutaneous coronary intervention (PCI) is the preferred plan of action for reperfusion in STEMI when it can be performed promptly by an experienced team [ 2 ]. To optimize outcomes, international guidelines laid by organizations such as the American College of Cardiology (ACC), American Heart Association (AHA), and European Society of Cardiology (ESC) suggest that the door-to-balloon (D2B) time defined as the time from the patient's arrival at the emergency department (ED) to inflation of the balloon in the infarct-related artery should be within 90 minutes in at least 90% of cases [ 3 – 5 ]. Achieving this benchmark requires seamless coordination among emergency physicians, nursing staff, interventional cardiologists, and cath lab personnel. In high-resource countries, methods have been optimized to meet this goal consistently. However, in low- and middle-income countries, like India, various systemic, logistical, and patient-level factors pose challenges in achieving timely PCI [ 6 , 7 ]. These factors may include lack of EMS pre-notification, delays in triage, diagnostic uncertainty, financial consent issues, or resource limitations. This clinical audit was conducted at SRM Medical College Hospital and Research Centre, a tertiary care center in Tamil Nadu, India. The aim of this audit was to evaluate institutional performance in achieving the benchmark D2B time of < 90 minutes in STEMI patients treated with primary PCI, by assessing system efficiency, identifying bottlenecks, and implementing targeted strategies for quality improvement. In the era of evidence-based practice and time-sensitive cardiology care, such audits are crucial in aligning clinical operations with global best practices and improving patient outcomes [ 8 ]. METHODS This retrospective clinical audit was conducted at SRM Medical College Hospital and Research Centre, a tertiary care academic institution in Tamil Nadu, India. The audit aimed to evaluate institutional performance in achieving the recommended D2B time of less than 90 minutes for patients presenting with STEMI and undergoing primary PCI. The audit period spanned from January 1 to December 31, 2024. All adult patients (≥ 18 years) who presented to the emergency department (ED) with chest pain and a diagnostic electrocardiogram (ECG) showing ST-segment elevation consistent with STEMI were screened. Patients who were confirmed to have STEMI and were treated with primary PCI were included in the audit (Fig. 1 ). Patients who received thrombolysis instead of PCI, those with contraindications to PCI, or those who experienced delays due to non-system factors such as patient or attender refusal of treatment, or financial consent issues were excluded from the audit. Data were extracted from the hospital’s emergency records, ECG logs, triage documentation, cardiology notes, and cardiac catheterization lab records. The following key time points were recorded: time of arrival at the ED (door time), time of ECG acquisition, time of PCI decision, and time of balloon inflation in the cath lab. A standardized audit proforma and spreadsheet were used to ensure uniform data collection. All data entries were verified by two independent auditors to ensure accuracy and consistency. The audit benchmark was based on the American Heart Association and European Society of Cardiology guideline recommending that at least 90% of eligible STEMI patients should undergo primary PCI within 90 minutes of arrival at the hospital. RESULTS Over the 12-month audit period from January to December 2024, a total of 657 patients presented to the ED at SRM Medical College Hospital and Research Centre with a confirmed diagnosis of STEMI, as established by clinical presentation and 12-lead ECG findings. Of these, 620 patients (94.4%) were deemed suitable for primary PCI and were promptly shifted to the cardiac catheterization laboratory for revascularization. This high proportion reflects effective early identification of STEMI cases and appropriate triage mechanisms in the ED. Among the 620 patients transferred to the cath lab, 564 patients (91.0%) successfully underwent balloon angioplasty within the recommended D2B time of 90 minutes or less, thus meeting the international benchmark set forth by the ACC and AHA. This result demonstrates that the institution’s STEMI care pathway achieved compliance with the recommended standard in more than nine out of every ten eligible patients. The mean D2B time for this group was approximately 76 ± 9.4 minutes, indicating not only successful target achievement but also relatively consistent performance with limited variation. However, 56 patients (9.0%) experienced delays with D2B times exceeding the 90-minute threshold (Table 1 ). A detailed evaluation of these delayed cases revealed multiple contributing factors. The most frequently encountered cause of delay, accounting for 21 cases (37.5%), was related to delays in obtaining informed consent, either due to unavailability of a legally authorized representative, language barriers, or hesitation from family members who needed more time to understand the procedure and associated risks. This highlights a critical bottleneck in the transition from diagnosis to intervention, particularly in a setting where attender decisions often significantly influence timely care delivery. Table 1 Summary of Causes for Door-to-Balloon Time Delays (> 90 minutes) Cause of Delay Number of Patients (n = 56) Percentage (%) Delay in obtaining informed consent 21 37.5 Hemodynamic instability / medical stabilization 18 32.1 Diagnostic ambiguity or atypical presentation 17 30.4 The second most common category of delay, observed in 18 patients (32.1%), was hemodynamic instability or presence of complex co-morbid conditions such as acute pulmonary edema, severe hypotension, diabetic ketoacidosis, or chronic kidney disease with electrolyte imbalance. These patients required stabilization with intravenous fluids, inotropes, non-invasive ventilation, or dialysis prior to transfer, which contributed to the procedural delay. These delays, while unavoidable in certain clinical situations, underscore the challenge of balancing patient safety with the urgency of reperfusion. In 17 patients (30.4%), delays were attributable to diagnostic ambiguity or atypical clinical presentation. These included patients with initial non-diagnostic or evolving ECG changes, unclear chest pain symptoms, or overlapping conditions such as pericarditis or left bundle branch block. In these cases, the need for confirmatory investigations and senior cardiologist consult delayed cath lab activation. Subgroup analysis showed no significant differences in delay rates based on gender or age; however, patients above 65 years were slightly more represented in the delayed group, suggesting a potential link between age-related comorbidities and procedural timing. Time-of-day analysis showed a modest increase in delay rates during night shifts (10.5%) compared to daytime hours (8.2%), likely reflecting logistical constraints and reduced staffing. Overall, the audit demonstrated that 91% of eligible STEMI patients received PCI within 90 minutes of ED arrival, with only 9% falling outside the benchmark, primarily due to modifiable system and patient-related factors. These findings highlight a robust STEMI care infrastructure while identifying specific opportunities for procedural enhancement and educational intervention. DISCUSSION This clinical audit aimed to assess the efficiency of door-to-balloon (D2B) time in patients with STEMI treated with primary PCI at a tertiary care academic center in India. The results demonstrated that 91% of eligible patients achieved a D2B time of ≤ 90 minutes, meeting the internationally endorsed benchmark recommended by the AHA and ESC, which suggests that at least 90% of STEMI patients should receive PCI within this time frame [ 1 , 2 ]. This high level of compliance reflects the success of coordinated STEMI care within the institution and aligns with similar outcomes reported by high-performing centers globally [ 3 ]. Timely primary PCI is a cornerstone of STEMI management, with extensive evidence showing that reductions in D2B time are associated with lower mortality, smaller infarct size, better left ventricular function, and improved long-term outcomes [ 4 , 5 ]. De Luca et al. demonstrated that every 30-minute delay in reperfusion therapy is associated with a 7.5% relative increase in 1-year mortality, highlighting the critical importance of system-wide efficiency in reducing treatment delays [ 6 ]. The achievement of a 91% compliance rate in this audit indicates the presence of effective interdepartmental collaboration between the emergency department, cardiology team, and catheterization laboratory. Several system enablers likely contributed to this success, including early ECG acquisition in the emergency department, prompt cardiology notification, and prioritization of STEMI cases in the cath lab. Moreover, the audit reflects the benefits of institutional protocols and trained emergency staff who are able to initiate the STEMI care pathway rapidly. However, despite the overall success, 9% of patients experienced D2B times exceeding 90 minutes. A closer analysis of these delays identified several recurring causes. Most notably, delayed informed consent accounted for more than one-third of the delays. In India and similar healthcare contexts, consent often depends not only on the patient but on family decision-making, which can be delayed by cultural, financial, or logistical barriers. Pinto et al. reported that non-clinical delays such as those due to communication, paperwork, or logistical hesitations are responsible for a substantial portion of treatment delays in STEMI care [ 7 ]. Another major factor identified was the need for hemodynamic stabilization before PCI in patients with comorbidities or presenting in cardiogenic shock. These delays are often unavoidable; however, early recognition and rapid initiation of resuscitative care can help minimize lost time. Studies by Menees et al. and Rathore et al. indicate that although shorter D2B times are generally associated with better outcomes, the benefit may be less pronounced in patients with shock or advanced comorbidity, where overall prognosis is more complex [ 8 , 9 ]. Diagnostic ambiguity also contributed to delayed reperfusion in a subset of patients. These included cases with atypical chest pain, non-diagnostic ECGs, or initial presentations confounded by other pathologies (e.g., left bundle branch block or pericarditis). As highlighted by Widimsky et al., real-time interpretation of ECGs and point-of-care diagnostics, along with access to cardiology consultation, are essential to ensure that subtle or ambiguous STEMI presentations are not missed or delayed [ 10 ]. The audit also observed that night-time presentations were marginally associated with increased delays, which is consistent with findings from global registries suggesting off-hour STEMI care is often slower due to reduced staff availability and increased response time [ 11 ]. This reaffirms the importance of 24/7 STEMI response teams and reinforced training of on-call personnel. While the audit successfully identified areas of strength, it also underscored the need for quality improvement strategies. These include implementing prehospital ECGs with electronic transmission, establishing a single-call “Code STEMI” activation protocol, and streamlining consent processes through pre-authorized forms or early patient and family education. Simulation-based drills and interprofessional training have also been shown to reduce cognitive and operational delays and could be incorporated into institutional practice [ 12 ]. Abbreviations Door-to-Balloon -D2B ST-elevation myocardial infarction -STEMI Percutaneous Coronary Intervention -PCI Emergency Department - ED Electrocardiogram-ECG American College of Cardiology -ACC American Heart Association - AHA Declarations Ethics approval and consent to participate: All procedures followed were in accordance with the ethical standards of the institutional ethical committee on human experimentation and with the Helsinki Declaration of 1975, as revised in 2008(5). Consent for publication: Individual informed consent was waived due to the retrospective nature of the study. Competing interests: None Funding: The authors gratefully acknowledge the financial support by SRM Medical College Hospital and Research Centre, Faculty of Medicine and Health Sciences, SRMIST, Kattankulathur for bearing the defrayed costs of publishing this article. Author Contribution R.K - Collection of data, manuscript preparation, Clinical analysis; R.K; C.M.D and S.H - Title, Manuscript preparation, Draft correction, Clinical analysis; A.M.P and S.B - Title ,Manuscript correction, Clinical analysis; B.K - Proof reading, Draft correction, . All authors reviewed and accepted the final draft of the manuscript. References O'Gara PT, Kushner FG, Ascheim DD, et al. 2013 ACCF/AHA guideline for the management of ST-elevation myocardial infarction. Circulation. 2013;127(4):e362–425. Ibanez B, James S, Agewall S, et al. 2017 ESC Guidelines for the management of acute myocardial infarction in patients presenting with ST-segment elevation. Eur Heart J. 2018;39(2):119–77. Nallamothu BK, Krumholz HM. Putting Quality Into Context — Lessons for the Future of Clinical Performance Measurement. N Engl J Med. 2007;356:653–5. Keeley EC, Boura JA, Grines CL. Primary angioplasty versus intravenous thrombolytic therapy for acute myocardial infarction: a quantitative review. Lancet. 2003;361(9351):13–20. Boersma E. Does time matter? A pooled analysis of randomized clinical trials comparing primary percutaneous coronary intervention and in-hospital fibrinolysis in acute myocardial infarction patients. Eur Heart J. 2006;27(7):779–88. De Luca G, Suryapranata H, Ottervanger JP, Antman EM. Time delay to treatment and mortality in primary angioplasty for acute myocardial infarction: every minute of delay counts. Circulation. 2004;109(10):1223–5. Pinto DS, Kirtane AJ, Nallamothu BK, et al. Hospital delays in reperfusion for ST-elevation myocardial infarction: implications when selecting a reperfusion strategy. Circulation. 2006;114(19):2019–25. Menees DS, Peterson ED, Wang Y, et al. Door-to-balloon time and mortality among patients undergoing primary PCI. N Engl J Med. 2013;369(10):901–9. Rathore SS, Curtis JP, Chen J, et al. Association of door-to-balloon time and mortality in patients admitted to hospitals in the United States. Circulation. 2009;119(10):1333–41. Widimsky P, Wijns W, Fajadet J, et al. Reperfusion therapy for ST elevation acute myocardial infarction in Europe: description of the current situation in 30 countries. Eur Heart J. 2010;31(8):943–57. Kostis WJ, Demissie K, Marcella SW, Shao YH, Wilson AC, Moreyra AE. Weekend and off-hour presentation and outcomes in patients with acute myocardial infarction. N Engl J Med. 2007;356(11):1099–109. Monsieurs KG, Nolan JP, Bossaert LL, et al. European Resuscitation Council Guidelines for Resuscitation 2015. Section 1. Executive summary. Resuscitation. 2015;95:1–80. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 17 Apr, 2026 Read the published version in International Journal of Emergency Medicine → Version 1 posted Reviewers agreed at journal 11 Mar, 2026 Reviewers agreed at journal 08 Mar, 2026 Reviewers agreed at journal 08 Mar, 2026 Reviewers agreed at journal 08 Mar, 2026 Reviews received at journal 07 Mar, 2026 Reviewers agreed at journal 06 Mar, 2026 Reviewers agreed at journal 06 Mar, 2026 Reviews received at journal 05 Mar, 2026 Reviews received at journal 02 Mar, 2026 Reviewers agreed at journal 02 Mar, 2026 Reviews received at journal 02 Mar, 2026 Reviewers agreed at journal 01 Mar, 2026 Reviewers agreed at journal 27 Feb, 2026 Reviewers agreed at journal 27 Feb, 2026 Reviewers agreed at journal 26 Feb, 2026 Reviewers agreed at journal 24 Feb, 2026 Reviews received at journal 23 Feb, 2026 Reviews received at journal 19 Feb, 2026 Reviewers agreed at journal 14 Feb, 2026 Reviewers agreed at journal 12 Feb, 2026 Reviews received at journal 10 Feb, 2026 Reviewers agreed at journal 10 Feb, 2026 Reviews received at journal 10 Feb, 2026 Reviewers agreed at journal 08 Feb, 2026 Reviewers agreed at journal 08 Feb, 2026 Reviews received at journal 07 Feb, 2026 Reviewers agreed at journal 06 Feb, 2026 Reviewers agreed at journal 29 Jan, 2026 Reviewers agreed at journal 29 Jan, 2026 Reviews received at journal 20 Nov, 2025 Reviewers agreed at journal 15 Nov, 2025 Reviewers agreed at journal 12 Nov, 2025 Reviewers agreed at journal 05 Nov, 2025 Reviewers agreed at journal 19 Oct, 2025 Reviewers agreed at journal 12 Oct, 2025 Reviewers invited by journal 11 Oct, 2025 Editor assigned by journal 22 Sep, 2025 Submission checks completed at journal 22 Sep, 2025 First submitted to journal 08 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. 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-7559914","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":533025947,"identity":"3f0abedf-deea-4b29-9603-7e5a47cabb00","order_by":0,"name":"Rajarajeswaran Krishnan","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA50lEQVRIiWNgGAWjYHCCBMaGHzZAmrGBAUJCGPi1NPakQRQfIFILUAnbYQjrAAMR6s3bDzz8OIPnvL35tMPNnz8w2MhuOMDc9gCfFpkzCcmSGyxuJ865ndgmcYAhzXjDAcZ2A3xaJBgSEiQf8NxOkJBObAM67HAiUEubBF4t/A+Sfz5gO2cP1NL84QDDfyK0SCSkSW5gO8A4QzqxAeiwA8RoeZBmObMnORGopU3ijEGy8czDBB2Wk3yz54cd0GHpjz9UVNjJ9h1vf4ZXCwMDTwISBxRUzPjVAwH7AYJKRsEoGAWjYIQDAPKbT7agRMfuAAAAAElFTkSuQmCC","orcid":"","institution":"SRM Medical College Hospital and Research Centre, Faculty of Medicine and Health Sciences , SRM Institute of Science \u0026 Technology,","correspondingAuthor":true,"prefix":"","firstName":"Rajarajeswaran","middleName":"","lastName":"Krishnan","suffix":""},{"id":533025948,"identity":"cf5c2f34-925f-4c26-a66a-0df1592eff1e","order_by":1,"name":"C. M. Dhileeban","email":"","orcid":"","institution":"SRM Medical College Hospital and Research Centre, Faculty of Medicine and Health Sciences , SRM Institute of Science \u0026 Technology,","correspondingAuthor":false,"prefix":"","firstName":"C.","middleName":"M.","lastName":"Dhileeban","suffix":""},{"id":533025949,"identity":"7f5e7e2d-acf5-44f3-9e57-ee58d38ed9ff","order_by":2,"name":"Hariprasad S","email":"","orcid":"","institution":"SRM Medical College Hospital and Research Centre, Faculty of Medicine and Health Sciences , SRM Institute of Science \u0026 Technology,","correspondingAuthor":false,"prefix":"","firstName":"Hariprasad","middleName":"","lastName":"S","suffix":""},{"id":533025950,"identity":"c42eaab0-54ba-4c7c-be64-200ad8dfd212","order_by":3,"name":"Ameen Umer P","email":"","orcid":"","institution":"SRM Medical College Hospital and Research Centre, Faculty of Medicine and Health Sciences , SRM Institute of Science \u0026 Technology,","correspondingAuthor":false,"prefix":"","firstName":"Ameen","middleName":"Umer","lastName":"P","suffix":""},{"id":533025951,"identity":"fa02490c-a17e-4878-804c-3abf1a0d66c6","order_by":4,"name":"S. Balaji","email":"","orcid":"","institution":"SRM Medical College Hospital and Research Centre, Faculty of Medicine and Health Sciences , SRM Institute of Science \u0026 Technology,","correspondingAuthor":false,"prefix":"","firstName":"S.","middleName":"","lastName":"Balaji","suffix":""},{"id":533025952,"identity":"1377bf43-35aa-420b-8c3d-a40864c5fc8e","order_by":5,"name":"Babu Kavitha","email":"","orcid":"","institution":"SRM Medical College Hospital and Research Centre, Faculty of Medicine and Health Sciences , SRM Institute of Science \u0026 Technology","correspondingAuthor":false,"prefix":"","firstName":"Babu","middleName":"","lastName":"Kavitha","suffix":""}],"badges":[],"createdAt":"2025-09-08 04:38:18","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7559914/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7559914/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s12245-026-01222-0","type":"published","date":"2026-04-17T15:59:39+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":94399495,"identity":"9d8d908a-2beb-440c-9c74-582f9866fd90","added_by":"auto","created_at":"2025-10-27 13:57:36","extension":"doc","order_by":0,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":139776,"visible":true,"origin":"","legend":"","description":"","filename":"ClinicalAuditpaperSubmittedDraft.doc","url":"https://assets-eu.researchsquare.com/files/rs-7559914/v1/8d8fbdfef77468cca3e03f70.doc"},{"id":94399805,"identity":"e3cad011-ad7f-4d1b-be9d-90508f7a8987","added_by":"auto","created_at":"2025-10-27 13:57:47","extension":"json","order_by":1,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":7467,"visible":true,"origin":"","legend":"","description":"","filename":"6f43c4c4571d4b0888d65f7830ee403b.json","url":"https://assets-eu.researchsquare.com/files/rs-7559914/v1/1f7711a4c23264e00ca5f590.json"},{"id":94398073,"identity":"500dcfda-0261-44d7-a0ad-032cebb94b50","added_by":"auto","created_at":"2025-10-27 13:56:58","extension":"xml","order_by":2,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":46622,"visible":true,"origin":"","legend":"","description":"","filename":"6f43c4c4571d4b0888d65f7830ee403b1enriched.xml","url":"https://assets-eu.researchsquare.com/files/rs-7559914/v1/cd39b3ef6501d1260e3b3921.xml"},{"id":94399851,"identity":"c46b6e9e-5631-4f5b-ba50-eeaf4c8793d6","added_by":"auto","created_at":"2025-10-27 13:57:49","extension":"png","order_by":3,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":70645,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-7559914/v1/3af176a9505055c643276abd.png"},{"id":94398986,"identity":"81d71cd3-2e3f-457f-9d73-a6fb86c51115","added_by":"auto","created_at":"2025-10-27 13:57:18","extension":"png","order_by":4,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":26487,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-7559914/v1/83e503851775e473be412bc0.png"},{"id":94398436,"identity":"48ffd7ae-6000-4d96-b17a-79f37bce267d","added_by":"auto","created_at":"2025-10-27 13:57:05","extension":"xml","order_by":5,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":43863,"visible":true,"origin":"","legend":"","description":"","filename":"6f43c4c4571d4b0888d65f7830ee403b1structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-7559914/v1/f8481485f35feb8720878f03.xml"},{"id":94398523,"identity":"bce56e0c-d620-4712-a471-e66dc61c1d2a","added_by":"auto","created_at":"2025-10-27 13:57:07","extension":"html","order_by":6,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":53368,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-7559914/v1/95bab0b38f9b088a18d7c69d.html"},{"id":94398972,"identity":"4425e807-8f82-45ec-a1b6-7072eeb4963f","added_by":"auto","created_at":"2025-10-27 13:57:17","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":55047,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eSTEMI Care Flowchart: From Presentation to Reperfusion\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eThis flowchart illustrates the institutional workflow for managing patients presenting with ST-elevation myocardial infarction (STEMI) in the emergency department. It outlines the critical steps from initial triage and ECG acquisition to cardiology notification, consent, and transfer to the catheterization laboratory for primary percutaneous coronary intervention (PCI). The diagram emphasizes decision-making timelines aimed at achieving a door-to-balloon (D2B) time of ≤90 minutes, in line with international guideline recommendations.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-7559914/v1/40668a9be84bd186b4d94ff8.png"},{"id":107351697,"identity":"f0902410-fb3b-4dbe-a36c-a892cdda1727","added_by":"auto","created_at":"2026-04-20 16:11:47","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":259034,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7559914/v1/4402738f-e884-47fa-9e9f-05f58ca91aa1.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Achieving Door-to-Balloon Time ≤90 Minutes in ST-Elevation Myocardial Infarction (STEMI): Results of a Retrospective Audit","fulltext":[{"header":"INTRODUCTION","content":"\u003cp\u003e\u003cb\u003eST-elevation myocardial infarction (STEMI)\u003c/b\u003e is one of the most critical cardiovascular emergencies, necessitating immediate medical intervention to restore myocardial perfusion and prevent irreversible ischemic damage. The principle of \u0026ldquo;\u003cb\u003etime is muscle\u003c/b\u003e\u0026rdquo; underscores the urgency in treating these patients: for every minute of delay in reperfusion therapy, a significant number of myocardial cells are lost, contributing to deterioration in morbidity and increased mortality [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Among the available treatment options, primary percutaneous coronary intervention (PCI) is the preferred plan of action for reperfusion in STEMI when it can be performed promptly by an experienced team [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eTo optimize outcomes, international guidelines laid by organizations such as the American College of Cardiology (ACC), American Heart Association (AHA), and European Society of Cardiology (ESC) suggest that the door-to-balloon (D2B) time defined as the time from the patient's arrival at the emergency department (ED) to inflation of the balloon in the infarct-related artery should be within 90 minutes in at least 90% of cases [\u003cspan additionalcitationids=\"CR4\" citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eAchieving this benchmark requires seamless coordination among emergency physicians, nursing staff, interventional cardiologists, and cath lab personnel. In high-resource countries, methods have been optimized to meet this goal consistently. However, in low- and middle-income countries, like India, various systemic, logistical, and patient-level factors pose challenges in achieving timely PCI [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. These factors may include lack of EMS pre-notification, delays in triage, diagnostic uncertainty, financial consent issues, or resource limitations.\u003c/p\u003e\u003cp\u003eThis clinical audit was conducted at SRM Medical College Hospital and Research Centre, a tertiary care center in Tamil Nadu, India. The aim of this audit was to evaluate institutional performance in achieving the benchmark D2B time of \u0026lt;\u0026thinsp;90 minutes in STEMI patients treated with primary PCI, by assessing system efficiency, identifying bottlenecks, and implementing targeted strategies for quality improvement. In the era of evidence-based practice and time-sensitive cardiology care, such audits are crucial in aligning clinical operations with global best practices and improving patient outcomes [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e].\u003c/p\u003e"},{"header":"METHODS","content":"\u003cp\u003e This retrospective clinical audit was conducted at SRM Medical College Hospital and Research Centre, a tertiary care academic institution in Tamil Nadu, India. The audit aimed to evaluate institutional performance in achieving the recommended D2B time of less than 90 minutes for patients presenting with STEMI and undergoing primary PCI. The audit period spanned from January 1 to December 31, 2024.\u003c/p\u003e\u003cp\u003eAll adult patients (\u0026ge;\u0026thinsp;18 years) who presented to the emergency department (ED) with chest pain and a diagnostic electrocardiogram (ECG) showing ST-segment elevation consistent with STEMI were screened. Patients who were confirmed to have STEMI and were treated with primary PCI were included in the audit (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Patients who received thrombolysis instead of PCI, those with contraindications to PCI, or those who experienced delays due to non-system factors such as patient or attender refusal of treatment, or financial consent issues were excluded from the audit.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eData were extracted from the hospital\u0026rsquo;s emergency records, ECG logs, triage documentation, cardiology notes, and cardiac catheterization lab records. The following key time points were recorded: time of arrival at the ED (door time), time of ECG acquisition, time of PCI decision, and time of balloon inflation in the cath lab. A standardized audit proforma and spreadsheet were used to ensure uniform data collection. All data entries were verified by two independent auditors to ensure accuracy and consistency. The audit benchmark was based on the American Heart Association and European Society of Cardiology guideline recommending that at least 90% of eligible STEMI patients should undergo primary PCI within 90 minutes of arrival at the hospital.\u003c/p\u003e"},{"header":"RESULTS","content":"\u003cp\u003eOver the 12-month audit period from January to December 2024, a total of 657 patients presented to the ED at SRM Medical College Hospital and Research Centre with a confirmed diagnosis of STEMI, as established by clinical presentation and 12-lead ECG findings. Of these, 620 patients (94.4%) were deemed suitable for primary PCI and were promptly shifted to the cardiac catheterization laboratory for revascularization. This high proportion reflects effective early identification of STEMI cases and appropriate triage mechanisms in the ED.\u003c/p\u003e\u003cp\u003eAmong the 620 patients transferred to the cath lab, 564 patients (91.0%) successfully underwent balloon angioplasty within the recommended D2B time of 90 minutes or less, thus meeting the international benchmark set forth by the ACC and AHA. This result demonstrates that the institution\u0026rsquo;s STEMI care pathway achieved compliance with the recommended standard in more than nine out of every ten eligible patients. The mean D2B time for this group was approximately 76\u0026thinsp;\u0026plusmn;\u0026thinsp;9.4 minutes, indicating not only successful target achievement but also relatively consistent performance with limited variation.\u003c/p\u003e\u003cp\u003eHowever, 56 patients (9.0%) experienced delays with D2B times exceeding the 90-minute threshold (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). A detailed evaluation of these delayed cases revealed multiple contributing factors. The most frequently encountered cause of delay, accounting for 21 cases (37.5%), was related to delays in obtaining informed consent, either due to unavailability of a legally authorized representative, language barriers, or hesitation from family members who needed more time to understand the procedure and associated risks. This highlights a critical bottleneck in the transition from diagnosis to intervention, particularly in a setting where attender decisions often significantly influence timely care delivery.\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\u003eSummary of Causes for Door-to-Balloon Time Delays (\u0026gt;\u0026thinsp;90 minutes)\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\u003cp\u003eCause of Delay\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eNumber of Patients (n\u0026thinsp;=\u0026thinsp;56)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003ePercentage (%)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDelay in obtaining informed consent\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e21\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e37.5\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHemodynamic instability / medical stabilization\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e18\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e32.1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDiagnostic ambiguity or atypical presentation\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e17\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e30.4\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eThe second most common category of delay, observed in 18 patients (32.1%), was hemodynamic instability or presence of complex co-morbid conditions such as acute pulmonary edema, severe hypotension, diabetic ketoacidosis, or chronic kidney disease with electrolyte imbalance. These patients required stabilization with intravenous fluids, inotropes, non-invasive ventilation, or dialysis prior to transfer, which contributed to the procedural delay. These delays, while unavoidable in certain clinical situations, underscore the challenge of balancing patient safety with the urgency of reperfusion.\u003c/p\u003e\u003cp\u003eIn 17 patients (30.4%), delays were attributable to diagnostic ambiguity or atypical clinical presentation. These included patients with initial non-diagnostic or evolving ECG changes, unclear chest pain symptoms, or overlapping conditions such as pericarditis or left bundle branch block. In these cases, the need for confirmatory investigations and senior cardiologist consult delayed cath lab activation.\u003c/p\u003e\u003cp\u003eSubgroup analysis showed no significant differences in delay rates based on gender or age; however, patients above 65 years were slightly more represented in the delayed group, suggesting a potential link between age-related comorbidities and procedural timing. Time-of-day analysis showed a modest increase in delay rates during night shifts (10.5%) compared to daytime hours (8.2%), likely reflecting logistical constraints and reduced staffing.\u003c/p\u003e\u003cp\u003eOverall, the audit demonstrated that 91% of eligible STEMI patients received PCI within 90 minutes of ED arrival, with only 9% falling outside the benchmark, primarily due to modifiable system and patient-related factors. These findings highlight a robust STEMI care infrastructure while identifying specific opportunities for procedural enhancement and educational intervention.\u003c/p\u003e"},{"header":"DISCUSSION","content":"\u003cp\u003eThis clinical audit aimed to assess the efficiency of door-to-balloon (D2B) time in patients with STEMI treated with primary PCI at a tertiary care academic center in India. The results demonstrated that 91% of eligible patients achieved a D2B time of \u0026le;\u0026thinsp;90 minutes, meeting the internationally endorsed benchmark recommended by the AHA and ESC, which suggests that at least 90% of STEMI patients should receive PCI within this time frame [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. This high level of compliance reflects the success of coordinated STEMI care within the institution and aligns with similar outcomes reported by high-performing centers globally [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eTimely primary PCI is a cornerstone of STEMI management, with extensive evidence showing that reductions in D2B time are associated with lower mortality, smaller infarct size, better left ventricular function, and improved long-term outcomes [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. De Luca et al. demonstrated that every 30-minute delay in reperfusion therapy is associated with a 7.5% relative increase in 1-year mortality, highlighting the critical importance of system-wide efficiency in reducing treatment delays [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThe achievement of a 91% compliance rate in this audit indicates the presence of effective interdepartmental collaboration between the emergency department, cardiology team, and catheterization laboratory. Several system enablers likely contributed to this success, including early ECG acquisition in the emergency department, prompt cardiology notification, and prioritization of STEMI cases in the cath lab. Moreover, the audit reflects the benefits of institutional protocols and trained emergency staff who are able to initiate the STEMI care pathway rapidly.\u003c/p\u003e\u003cp\u003eHowever, despite the overall success, 9% of patients experienced D2B times exceeding 90 minutes. A closer analysis of these delays identified several recurring causes. Most notably, delayed informed consent accounted for more than one-third of the delays. In India and similar healthcare contexts, consent often depends not only on the patient but on family decision-making, which can be delayed by cultural, financial, or logistical barriers. Pinto et al. reported that non-clinical delays such as those due to communication, paperwork, or logistical hesitations are responsible for a substantial portion of treatment delays in STEMI care [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eAnother major factor identified was the need for hemodynamic stabilization before PCI in patients with comorbidities or presenting in cardiogenic shock. These delays are often unavoidable; however, early recognition and rapid initiation of resuscitative care can help minimize lost time. Studies by Menees et al. and Rathore et al. indicate that although shorter D2B times are generally associated with better outcomes, the benefit may be less pronounced in patients with shock or advanced comorbidity, where overall prognosis is more complex [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eDiagnostic ambiguity also contributed to delayed reperfusion in a subset of patients. These included cases with atypical chest pain, non-diagnostic ECGs, or initial presentations confounded by other pathologies (e.g., left bundle branch block or pericarditis). As highlighted by Widimsky et al., real-time interpretation of ECGs and point-of-care diagnostics, along with access to cardiology consultation, are essential to ensure that subtle or ambiguous STEMI presentations are not missed or delayed [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThe audit also observed that night-time presentations were marginally associated with increased delays, which is consistent with findings from global registries suggesting off-hour STEMI care is often slower due to reduced staff availability and increased response time [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. This reaffirms the importance of 24/7 STEMI response teams and reinforced training of on-call personnel.\u003c/p\u003e\u003cp\u003eWhile the audit successfully identified areas of strength, it also underscored the need for quality improvement strategies. These include implementing prehospital ECGs with electronic transmission, establishing a single-call \u0026ldquo;Code STEMI\u0026rdquo; activation protocol, and streamlining consent processes through pre-authorized forms or early patient and family education. Simulation-based drills and interprofessional training have also been shown to reduce cognitive and operational delays and could be incorporated into institutional practice [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e].\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003col\u003e\n \u003cli\u003eDoor-to-Balloon -D2B\u003c/li\u003e\n \u003cli\u003eST-elevation myocardial infarction -STEMI\u0026nbsp;\u003c/li\u003e\n \u003cli\u003ePercutaneous Coronary Intervention -PCI\u003c/li\u003e\n \u003cli\u003eEmergency Department - ED\u003c/li\u003e\n \u003cli\u003eElectrocardiogram-ECG\u003c/li\u003e\n \u003cli\u003eAmerican College of Cardiology -ACC\u003c/li\u003e\n \u003cli\u003eAmerican Heart Association - AHA\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate:\u003c/strong\u003e\u003cp\u003e All procedures followed were in accordance with the ethical standards of the institutional ethical committee on human experimentation and with the Helsinki Declaration of 1975, as revised in 2008(5).\u003c/p\u003e\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eConsent for publication:\u003c/strong\u003e\u003cp\u003e Individual informed consent was waived due to the retrospective nature of the study.\u003c/p\u003e\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eCompeting interests:\u003c/strong\u003e\u003cp\u003eNone\u003c/p\u003e\u003c/p\u003e\u003ch2\u003eFunding:\u003c/h2\u003e\u003cp\u003eThe authors gratefully acknowledge the financial support by SRM Medical College Hospital and Research Centre, Faculty of Medicine and Health Sciences, SRMIST, Kattankulathur for bearing the defrayed costs of publishing this article.\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eR.K - Collection of data, manuscript preparation, Clinical analysis; R.K; C.M.D and S.H - Title, Manuscript preparation, Draft correction, Clinical analysis; A.M.P and S.B - Title ,Manuscript correction, Clinical analysis; B.K - Proof reading, Draft correction, . All authors reviewed and accepted the final draft of the manuscript.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eO'Gara PT, Kushner FG, Ascheim DD, et al. 2013 ACCF/AHA guideline for the management of ST-elevation myocardial infarction. Circulation. 2013;127(4):e362\u0026ndash;425.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eIbanez B, James S, Agewall S, et al. 2017 ESC Guidelines for the management of acute myocardial infarction in patients presenting with ST-segment elevation. Eur Heart J. 2018;39(2):119\u0026ndash;77.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eNallamothu BK, Krumholz HM. Putting Quality Into Context \u0026mdash; Lessons for the Future of Clinical Performance Measurement. N Engl J Med. 2007;356:653\u0026ndash;5.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKeeley EC, Boura JA, Grines CL. Primary angioplasty versus intravenous thrombolytic therapy for acute myocardial infarction: a quantitative review. Lancet. 2003;361(9351):13\u0026ndash;20.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBoersma E. Does time matter? A pooled analysis of randomized clinical trials comparing primary percutaneous coronary intervention and in-hospital fibrinolysis in acute myocardial infarction patients. Eur Heart J. 2006;27(7):779\u0026ndash;88.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDe Luca G, Suryapranata H, Ottervanger JP, Antman EM. Time delay to treatment and mortality in primary angioplasty for acute myocardial infarction: every minute of delay counts. Circulation. 2004;109(10):1223\u0026ndash;5.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePinto DS, Kirtane AJ, Nallamothu BK, et al. Hospital delays in reperfusion for ST-elevation myocardial infarction: implications when selecting a reperfusion strategy. Circulation. 2006;114(19):2019\u0026ndash;25.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMenees DS, Peterson ED, Wang Y, et al. Door-to-balloon time and mortality among patients undergoing primary PCI. N Engl J Med. 2013;369(10):901\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRathore SS, Curtis JP, Chen J, et al. Association of door-to-balloon time and mortality in patients admitted to hospitals in the United States. Circulation. 2009;119(10):1333\u0026ndash;41.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWidimsky P, Wijns W, Fajadet J, et al. Reperfusion therapy for ST elevation acute myocardial infarction in Europe: description of the current situation in 30 countries. Eur Heart J. 2010;31(8):943\u0026ndash;57.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKostis WJ, Demissie K, Marcella SW, Shao YH, Wilson AC, Moreyra AE. Weekend and off-hour presentation and outcomes in patients with acute myocardial infarction. N Engl J Med. 2007;356(11):1099\u0026ndash;109.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMonsieurs KG, Nolan JP, Bossaert LL, et al. European Resuscitation Council Guidelines for Resuscitation 2015. Section 1. Executive summary. Resuscitation. 2015;95:1\u0026ndash;80.\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":"international-journal-of-emergency-medicine","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ijem","sideBox":"Learn more about [International Journal of Emergency Medicine](https://intjem.biomedcentral.com/)","snPcode":"12245","submissionUrl":"https://submission.nature.com/new-submission/12245/3","title":"International Journal of Emergency Medicine","twitterHandle":"@IntJEmergMed","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"STEMI, door-to-balloon time, primary PCI, clinical audit, emergency cardiology, reperfusion delay, India","lastPublishedDoi":"10.21203/rs.3.rs-7559914/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7559914/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e\u003cp\u003eTimely reperfusion therapy with primary percutaneous coronary intervention (PCI) significantly improves outcomes in ST-elevation myocardial infarction (STEMI). Current international guidelines recommend achieving a door-to-balloon (D2B) time of \u0026le;\u0026thinsp;90 minutes in at least 90% of eligible patients. This audit aimed to evaluate institutional adherence to this benchmark at a tertiary care center in India.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e\u003cp\u003eA retrospective clinical audit was conducted at SRM Medical College Hospital and Research Centre over a 12-month period (January\u0026ndash;December 2024). All adult STEMI patients who underwent primary PCI were included. Patients treated with thrombolysis or with non-system-related delays were excluded. Key time points, including emergency department (ED) arrival, ECG, PCI decision, and balloon inflation, were analyzed. The primary outcome was the percentage of patients achieving D2B time\u0026thinsp;\u0026le;\u0026thinsp;90 minutes.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e\u003cp\u003eAmong 657 STEMI patients presenting to the ED, 620 (94.4%) were taken for primary PCI. Of these, 564 patients (91.0%) achieved a D2B time within 90 minutes, meeting the international benchmark. Delays beyond 90 minutes were noted in 56 patients (9.0%), primarily due to delayed consent (37.5%), need for medical stabilization (32.1%), and diagnostic ambiguity (30.4%).\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e\u003cp\u003e The audit confirmed that coordinated STEMI care at our center achieved the international D2B benchmark in 91% of eligible patients. However, system and patient-level delays remain a challenge. Interventions such as rapid consent pathways, enhanced triage protocols, and continuous team training are recommended to further reduce treatment delays and optimize patient outcomes.\u003c/p\u003e","manuscriptTitle":"Achieving Door-to-Balloon Time ≤90 Minutes in ST-Elevation Myocardial Infarction (STEMI): Results of a Retrospective Audit","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-26 01:19:38","doi":"10.21203/rs.3.rs-7559914/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewerAgreed","content":"318215469489099399174835128115177436848","date":"2026-03-11T13:17:16+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"48003687183843423369533942240035820322","date":"2026-03-08T16:33:29+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"193953430922049169434407229628503041331","date":"2026-03-08T15:26:16+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"62195315875453629139115423707601283849","date":"2026-03-08T15:21:37+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-07T08:33:28+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"291171822103961473542949133864442426032","date":"2026-03-06T17:04:14+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"109024555135136979955622749575750534053","date":"2026-03-06T16:30:02+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-05T09:45:29+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-02T12:57:13+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"253625895542177164294379437543384835990","date":"2026-03-02T12:48:27+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-02T05:06:23+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"106294438483214680400270679613786476111","date":"2026-03-01T17:02:06+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"147160056885422194325718905044334049397","date":"2026-02-27T17:05:32+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"246943483691587221695592403670055036273","date":"2026-02-27T07:40:34+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"56256828237369189969924347697561113047","date":"2026-02-26T17:05:40+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"121106783730342860853980221828803480097","date":"2026-02-24T14:40:03+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-02-23T21:15:59+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-02-19T13:40:31+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"215591126431511051136639521493756885868","date":"2026-02-14T06:35:19+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"173626587072725860161478336263302367196","date":"2026-02-13T02:05:43+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-02-10T16:38:25+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"94653597248133296760979703684670114732","date":"2026-02-10T16:32:34+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-02-10T07:23:16+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"210610277008255211913280573850750562583","date":"2026-02-08T18:42:07+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"81495987156821954112691801409275942755","date":"2026-02-08T15:49:02+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-02-07T19:31:59+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"236953719862365015883337371057435437706","date":"2026-02-06T15:44:01+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"3171472895299582618972833090972207736","date":"2026-01-29T15:02:21+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"35577677115572962607613564537880334527","date":"2026-01-29T11:35:28+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-11-21T02:59:48+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"264253608921560972858922954017901194662","date":"2025-11-15T17:42:21+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"164266896995364945631297928640586911472","date":"2025-11-12T19:33:00+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"275750067941793433769418855068239095951","date":"2025-11-05T05:19:15+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"242714111957328973775926639078380703235","date":"2025-10-19T08:05:11+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"99821355964542992727519638495469744661","date":"2025-10-12T04:54:10+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-10-11T20:25:05+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-09-23T00:32:11+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-09-22T04:51:36+00:00","index":"","fulltext":""},{"type":"submitted","content":"International Journal of Emergency Medicine","date":"2025-09-08T04:33:32+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"international-journal-of-emergency-medicine","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ijem","sideBox":"Learn more about [International Journal of Emergency Medicine](https://intjem.biomedcentral.com/)","snPcode":"12245","submissionUrl":"https://submission.nature.com/new-submission/12245/3","title":"International Journal of Emergency Medicine","twitterHandle":"@IntJEmergMed","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"ef3c8ce9-eb8b-4ea9-a824-b2dfe58d4669","owner":[],"postedDate":"October 26th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2026-04-20T16:08:03+00:00","versionOfRecord":{"articleIdentity":"rs-7559914","link":"https://doi.org/10.1186/s12245-026-01222-0","journal":{"identity":"international-journal-of-emergency-medicine","isVorOnly":false,"title":"International Journal of Emergency Medicine"},"publishedOn":"2026-04-17 15:59:39","publishedOnDateReadable":"April 17th, 2026"},"versionCreatedAt":"2025-10-26 01:19:38","video":"","vorDoi":"10.1186/s12245-026-01222-0","vorDoiUrl":"https://doi.org/10.1186/s12245-026-01222-0","workflowStages":[]},"version":"v1","identity":"rs-7559914","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7559914","identity":"rs-7559914","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}