Efficacy and safety of ticagrelor versus clopidogrel with different dosage in high-risk patients with acute coronary syndrome.

Background: Dual antiplatelet therapy is recommended as a standard antiplatelet strategy in acute coronary syndrome. For those with reduced pharmacologic response to clopidogrel, strengthening antiplatelet therapy (clopidogrel 150mg daily) may reduce adverse clinical events. Ticagrelor is a direct-acting inhibitor of the adenosine diphosphate receptor P2Y12 that has a more rapid onset and offset than clopidogrel.

Methods: In this retrospective study, we compared ticagrelor (180mg loading dose 90mg twice daily thereafter), clopidogrel (300mg loading dose, 75mg or 150mg daily thereafter) for the prevention of cardiovascular events in 273 high-risk patients admitted to coronary care unit with acute coronary syndrome.

Results: The rate of IST in hospital was significantly reduced in patients of ticagrelor group comparing with those receiving clopidogrel 75mg (0.69% vs 8.2%, p=0.009). Moreover, the TVR rate was less in the ticagrelor group than clopidogrel 75mg group (2.7% vs 13.1%, p=0.007) 6months follow-up. The incidence of MACCE has no difference between the two clopidogrel groups. Kaplan-Meier analysis of MACCE-free indicated that there was no difference between the three groups. Ticagrelor significantly increased the rate of minor bleeding compared with clopidogrel 75mg daily during hospital (45.5% vs 26.2%,p=0.012) and 6-month follow-up (66.9% vs 45.9%,p=0.004).Bleeding-free prognosis was significantly better in the clopidogrel 75mg daily group.

Conclusions: In patients with acute coronary syndrome undergoing PCI, the rate of in-stent thrombosis and TVR were significantly reduced treated with ticagrelor compared with clopidogrel 75mg daily, without an increase of overall major bleeding, but with an increase of minor bleeding.