Abstract: AIM: To investigate the effect of tirofiban on the level of platelet microparticles(PMPs) in patients with acute ST-segment elevation myocardial infarction undergoing emergency interventional treatment. METHODS: 62 patients with acute ST-segment elevation myocardial infarction undergoing emergency interventional treatment were randomly divided into the tirofiban group (intravenous tirofiban 10 μg/kg bolus then 0.15 μg·kg^-1·min^-1 intravenous continuous infusion for 36 h, 32 cases) and control group (without tirofiban, 30 cases). The levels of PMPs were assessed before tirofiban infusion, at 10 min and 24 hours after tirofiban infusion, and at 12 hours after stopping tirofiban infusion by the flow cytometry. RESULTS: There was no significant difference in baseline of PMPs between tirofiban group and control group (P＞0.05). The level of PMPs was significantly lower in tirofiban group (5.1%±2.7%) compared with control group(6.7%±3.2%)(P<0.01) at 10 mins after tirofiban infusion.At 24 hours after tirofiban infusion, the level of PMPs in tirofiban group was significantly lower than that in control group(P=0.03).The level of PMPs was similar at 12 after stopping tirofiban use between the 2 groups(P>0.05). CONCLUSION: Tirofiban can effectively reduce the number of PMPs in patients with acute ST-segment elevation myocardial infarction undergoing emergency interventional treatment, achieve the purpose of the inhibition of activated platelets quickly.

Key words: ST-segment elevation acute myocardial infarction, platelet microparticles, tirofiban, percutaneous coronary intervention