In patients with acute ST-segment elevation myocardial infarction (STEMI), percutaneous coronary intervention (PCI) may cause thrombus dislodgment and impaired microcirculatory reperfusion. This study was designed to test the hypothesis that thrombus aspiration before standard PCI may improve acute myocardial reperfusion, measured by ST-segment resolution (STR) and myocardial blush grade (MBG), compared with standard PCI.

Consecutive STEMI patients, admitted within 12 hours of symptom onset and scheduled for primary PCI are randomly assigned to two treatment strategies: standard PCI including stenting and abciximab (group1) or thrombus aspiration with Pronto™ extraction catheter (Vasc.solutions, Minneapolis) before standard PCI (group2). Patients with cardiogenic shock, previous infarction or thrombolytic therapy are excluded.

Inclusion Criteria:

• ST-segment elevation myocardial infarction patients undergoing primary angioplasty within 12 hours from symptom onset.

Exclusion Criteria:

• Cardiogenic shock, previous infarction, previous coronary bypass surgery,bundle branch block or pacemaker induced rythm, controindications to IIb/IIIa inhibitors.