Sample size: 45 subjects~Site Locations: Sheba medical center~Patients: Patients presenting with an acute MI with onset of symptoms  6h, and planned to undergo primary PCI will be included. The target lesion should be located in the proximal or middle segment of a main native coronary artery, and should be suitable for percutaneous intervention.~Primary Objective: To determine the safety and efficacy of 2 vs 4 cycles of postconditioning method during primary PCI and direct stenting in acute MI, and to compared to primary PCI and direct stenting without the postconditioning.~Primary Endpoint:~ST segment resolution.~Segmental wall motion score, resolution of edema and wall thickness by echocardiography.~Infarct size estimation by cardiac enzymes and cardiac MRI.~Secondary endpoints:~Composite endpoint of Major Adverse Cardiac Events (MACE) at 30 and 90 days~Methods:~ECG at baseline, immediately after procedure, 90 and 180 minutes after the procedure and 6-24 hours after intervention.~Core laboratory angiography measurements of TIMI flow, corrected TIMI Frame count, myocardial blush score and left ventricular angiography.~Myocardial enzymes measurements: every 4 hours in the first 24 hours and every 6 hours in the following 48 hours.~Left ventricular ejection fraction and wall motion score determined by echocardiography.~Cardiac MRI estimation of infarct size. • Clinical follow-up at 30 and 90 days post procedure.~Follow-up:~Follow up at 30 days: Clinical.~Clinical Follow up & Cardiac MRI at 90 days.
To determine the safety and efficacy of 2 vs 4 cycles of postconditioning method during primary PCI and direct stenting in acute MI, and to compared to primary PCI and direct stenting without the postconditioning.