Rationale and design of the POSTEMI (postconditioning in ST-elevation myocardial infarction) study

Rapid reperfusion of the infarct-related coronary artery is essential in the treatment of acute ST-elevation myocardial infarction (STEMI). Paradoxically, restoration of the blood flow to the ischemic area may result in further injury to the myocardium. This phenomenon is described as 'ischemia/reperfusion injury' and the pathophysiological mechanisms are not fully elucidated. A cardioprotective effect of ischemic postconditioning (short repetitive cycles of reperfusion and re-occlusion) has been demonstrated in experimental studies and in pilot studies on patients with acute STEMI treated with primary percutaneous coronary intervention. We present the study design of the Postconditioning in ST-Elevation Myocardial Infarction (POSTEMI) study, which is a prospective, randomized, open-label clinical trial with blinded endpoint evaluation designed to evaluate the effect of postconditioning on final infarct size. Patients with acute STEMI with symptoms of less than 6 h and proximal or mid-coronary artery occlusion will be included. The primary endpoint is infarct size, assessed by cardiac MRI after 4 months. The secondary endpoints are to evaluate the effect of postconditioning on TIMI myocardial perfusion grade, resolution of ST-segment elevation, release of markers of ischemia, left ventricular function and final infarct size related to the area at risk. A total of 260 patients will be included in the study.