Rapid use of high-sensitive cardiac troponin I for ruling-in and ruling-out of acute myocardial infarction (RACING-MI): study protocol.

Introduction: The European Society of Cardiology has suggested an accelerated algorithm for ruling-in and ruling-out myocardial infarction (MI) with high-sensitive cardiac troponin (hs-cTn) measured at admission (0 hour) and after 1 hour (1 hour) as an alternative to standard measurements at 0 hour and 3 hours. However, the 0 hour/1 hour algorithm has only been tested in a limited amount of patient cohorts and not for all hs-cTn assays. Moreover, it is unknown if MI can be ruled-out faster than 1 hour. In this single-centre, clinical trial, we will investigate whether MI safely can be ruled-in or ruled-out after 30 min and 1 hour. Methods and analysis: Patients with chest pain suggestive of MI admitted to the emergency department will be subjected to hs-cTn measurements at the following time points: 0 hour, 30 min, 1 hour and 3 hours. Chest pain characteristics will be recorded. In total, 1000 patients with all four blood samples will be included. The diagnostic algorithms will be derived based on the first 500 patients and validated in the subsequent 500 patients. The primary endpoint is the negative predictive value of the 0 hour/30 min and the 0 hour/1 hour algorithms. Secondary endpoints include positive predictive value, sensitivity and specificity. Results will be compared with the standard 0 hour/3 hour algorithm. Ethics and dissemination: Oral and written informed consent will be obtained from all patients. The trial is approved by The Regional Committee on Health Research Ethics and the Danish Data Protection Agency. Data will be disseminated and submitted to peer-reviewed scientific journals and meetings irrespective of study outcome. Trial registration number: NCT03634384.