Remote Ischemic Perconditioning in Patients With ST-segment Elevation Myocardial Infarction

ST-elevation myocardial infarction (STEMI) is a leading cause of mortality and morbidity. Early myocardial reperfusion with either of thrombolytic therapy or primary percutaneous coronary intervention (PPCI) is the most effective strategy for reducing the size of a myocardial infarct and improving the clinical outcome. Although this process can restore blood flow to the ischemic myocardium, it can induce injury. This phenomenon termed myocardial reperfusion injury can paradoxically reduce the beneficial effects of myocardial reperfusion. The pre-clinical study in animal models of acute myocardial infarction suggests that lethal reperfusion injury accounts for up to 50% of the final size of a myocardial infarct.

Remote ischemic conditioning uses brief ischemia and reperfusion of a distant organ to protect the myocardium. In animal study, remote ischemic postconditioning seems to be more effective than local postconditioning in experimental myocardial infarction.Bøtker et al. has reported remote ischemic preconditioning before hospital admission increase myocardial salvage in patients with acute myocardial infarction.

The objective of this study is to evaluate whether remote ischemic per-conditioning (RIPC) can reduce late infarct size in patients with STEMI treated with PPCI within 12 hours of symptoms onset. To test this hypothesis, we will randomize patients into PPCI + RIPC or PPCI alone. We will evaluate marker of reperfusion injury using contrast cardiac magnetic resonance image.

Inclusion criteria

• Age >19 years
• Presenting within 12 hours of symptom onset
• >20 min of chest pain
• ST-elevation myocardial infarction defined as ST-segment elevation (>0.1 mV) in at least 2 contiguous precordial leads

Exclusion criteria

• Previous myocardial infarction
• Presence of chronic total occlusion
• Evidence of retrograde filling by collaterals at coronary angiography (Rentrop 2 or 3 collateral flow)
• Severe multi-vessel coronary artery disease to require further interventions before follow-up CMR
• Cardiac arrest before randomization
• Arrhythmias requiring external electric shock before randomization
• Unwillingness to participate
• External electric shock for cardioversion within first 3 days
• Cardiac surgery within first 3 days