The POST-conditioning during coronary angioplasty in Acute Myocardial Infarction (POST-AMI) trial will evaluate the usefulness of postconditioning in limiting infarct size and microvascular damage during the early and late phases after AMI.

POST-AMI is a single-center, prospective, randomized trial, with a planned inclusion of 78 patients with ST-elevation Acute Myocardial Infarction (AMI). Patients will be randomly assigned to postconditioning arm (primary angioplasty (PA) and stenting followed by brief episodes of ischemia-reperfusion performed during the first minutes of reperfusion) or non-postconditioning arm (PA and stenting without additional intervention). All patients will be treated medically according to current international guidelines, including glycoprotein IIb/IIIa inhibitors before PCI. The primary end point is to evaluate whether postconditioning, compared to PA without additional intervention, reduces infarct size estimated by magnetic resonance at 30±10 days after the AMI. Secondary end points are microvascular obstruction observed at magnetic resonance, ST-segment elevation resolution, persistent ST-segment elevation, angiographic myocardial blush grade <2 and non sustained/sustained ventricular tachycardia in the 48 hours following PA. Further secondary end points are enzymatic infarct size, left ventricular remodeling and left ventricular function at magnetic resonance performed at 6±1 months, and the reduction of major adverse cardiac events at 30 days and 6 months.

Inclusion Criteria:

• clinical evidence of myocardial infarction defined by the presence of ischemic chest pain lasting more than 30 minutes, with a time interval from the onset of symptoms less than 6 hours before hospital admission, associated with typical ST-segment elevation on the 12-lead ECG
• angiographic-detected culprit lesion with stenosis diameter >70% and TIMI flow grade <=1

Exclusion Criteria:

• previous acute myocardial infarction
• previous myocardial revascularization (angioplasty or coronary bypass)
• previous heart valve replacement
• previous heart transplant
• clinical instability precluding the suitability of the study
• cardiogenic shock or persistent hypotension (systolic blood pressure <100 mmHg)
• rescue angioplasty after thrombolytic therapy
• evidence of coronary collaterals (Rentrop grade>0) in the risk area
• advanced atrioventricular block
• significant bradycardia
• absence of sinus rhythm
• inability to lay flat (due to severe cardiac heart failure/respiratory insufficiency)
• history or clinical evidence of bronchospastic lung disease
• pregnancy
• known existence of a life-threatening disease with a life expectancy <6 months
• inability to give informed consent
• any contraindication to undergo cardiac-MRI, such as implanted metallic objects (cardiac pacemakers and/or implantable cardioverter defibrillator, implanted insulin pumps or any other type of electronic devices, cerebral clips, aneurysm clips) or any other contraindication to cardiac-MRI (such as claustrophobia)