Comparison Of The Antiplatelet Effect Between Ticagrelor And Clopidogrel In Chinese Patients With Acute Myocardial Infarction After Primary Percutaneous Coronary Intervention

Background: Ticagrelor can provide effective platelet inhibition 2 hours after a loading dose, but it will take 6 hours for clopidogrel. It is not very clear whether the anthplatelet agents treated patients with AMI undergoing primary PCI can achieve ideal antiplatelet effect after 24 to 48 hours. Purpose: The aim is to compare the antiplatelet action between ticagrelor and clopidogrel in Chinese patients with AMI after primary PCI. Methods: 189 patients with AMI after primary PCI were enrolled in this single center registry. All patients received loading and maintenance dose of dual antiplatelet therapy (aspirin+clopidogrel/ticagrelor). 58 cases were included in ticagrelor group. 131 patients were included in clopidogrel group. Residual platelet reactivity was assessed by VerifyNow 24-48 hours after PCI. All patients were followed-up for 30 days and 6 months after discharge. Results: The baseline data were well matched between the two groups. After 24-48 hours, 51 cases existed of high residual platelet response(HRPR)(platelet response unit ,PRU≥230), the ratio was 26.98%. In clopidogrel group, the average PRU was 195.8 (26~329), and 43 patients existed HRPR, ratio was 32.82%. For ticagrelor group, the average PRU was 101.8 (6~322), and 8 patients existed HRPR, ratio was 14.04%. The incidence of HRPR was significantly lower in ticagrelor group ( p < 0.0001). Within 30 days, the incidence of MI in clopidogrel group and ticagrelor group were respectively 0.8% and 0, p =0.693; target lesion revascularization were 1.7% and 1.5%, p =0.669; death were 0.8% and 0, p =0.693; stroke were 0 and 0, p =1.000; bleeding were 2.3% and 0, p =0.331. In 6 months, the incidence of MI were 0.8% and 0, p =0.693; target lesion revascularization were 0.8% and 0, p =0.693; death were 0 and 0, p =1.000. The incidence of MACE, bleeding and stroke had no obvious difference between the two groups. Conclusion: 24 hours after primary PCI, there are still a large proportion of Chinese patients with AMI existing insufficient platelet inhibition, no matter they take clopidogrel or ticagrelor, but ticagrelor has a significant stronger antiplatelet effect than clopidogrel. There is no obvious difference between the incidences of clinical events.