Mi Q Wave clinical trials

New Time Clock for ST-elevation MI Based on Biochemical Myocardial Infarction Onset Time

ST segment elevation myocardial infarction (STEMI) is one of the leading causes of death across the world and immediate treatment with either thrombolytics or percutaneous coronary intervention (PCI) results in lower mortality. It is essential to accurately determine the time of onset of myocardial infarction. Standard practice is to take the time of symptom onset as a surrogate for artery occlusion time. However symptom onset is a subjective parameter and affected by multiple factors such as recall issues in elderly patients and preceding unstable angina symptoms before artery occlusion. In a recent study by Mahmoud et al. an objective method, biochemical onset time is proposed for estimation of artery occlusion time using serial cardiac troponin T (cTnT) levels in patients with STEMI. However, this study was retrospective, had an average of two measurements of cTnT for each patient, peak troponin level was frequently missing and newer earlier detectable biomarkers such as high sensitive Troponin I (hsTnI) were not used. We plan to use multiple samples of hsTnI for each patient using the same method as above and we will compare the biochemical ischemic time with the patient reported symptom onset time. Secondarily, we will try to determine whether a single sample of multiple cardiac biomarkers with different release kinetics drawn at time of patient presentation in emergency room (ER) could predict precise time of onset of myocardial infarction. OBJECTIVES 1. To determine the biochemical onset time using multiple hsTnI measurements from each patient (zero, 03, 08, 24 hrs), and compare this biochemical time to the patient-reported symptoms onset time as an indicator of coronary artery occlusion. 2. To predict biochemical occlusion at the time of presentation with the use of single sample of six different markers of myocardial injury. 3. To assess the association of conventional ischemic time and biochemical ischemic time with infarct size; using peak hsTnI, percent ejection fraction by Echocardiography and Cardiac Magnetic Resonance imaging (CMR) based infarct volume in grams. 4. To assess the association of conventional ischemic time and biochemical ischemic time with in-hospital and 30-days major adverse cardiac events, MACE; a composite of heart failure, shock, re MI or death. A prospective nonintervention pilot study will include 100 consecutive patients coming with acute STEMI. Patients' recruitment will be done in ER of Tabba Heart Institute, Karachi Pakistan.