Effects of tirofiban on platelet activation and endothelial function in patients with ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention.

This pilot study examined, for the first time, the effect of intracoronary administration of tirofiban, an inhibitor of platelet aggregation, on platelet activation and endothelial dysfunction in patients with ST-segment-elevated myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI). A total of 119 STEMI patients were randomized into either tirofiban group (n = 72, intracoronary injection of 10 μg/kg tirofiban prior to PCI, followed by intravenous infusion at 0.15 μg/kg min) or a control group (n = 47), which did not receive tirofiban. Periprocedural administration of tirofiban was associated with significantly reduced levels of platelet activation (lower levels of CD62P and PAC-1) and endothelial dysfunction (reduced levels of endothelial microparticles, VCAM-1, and ICAM-1) 48 h after PCI. At 10 days after PCI, patients in the tirofiban group had a higher incidence of complete STR (78.7 vs. 65.0%) and higher left ventricular ejection fractions (47.8 vs. 44.2) compared to those in the control group. The clinical outcomes between two groups did not differ significantly two weeks after treatment. The results demonstrated that periprocedural administration of tirofiban is associated with significantly attenuated platelet activation and endothelial dysfunction in STEMI patients undergoing PCI. This may have contributed to the improved myocardial reperfusion and preservation of left ventricular systolic function in these patients.