Ticagrelor vs Clopidogrel in Acute Myocardial Infarction Patients With a History of Ischemic Stroke

Objective: To investigate whether use of ticagrelor compared to clopidogrel is associated with different risks for thrombotic events or major bleeding among acute myocardial infarction (AMI) patients with a prior history of acute ischemic stroke. Patients and Methods: This retrospective cohort study used the Health and Welfare Database in Taiwan. Stroke patients prescribed ticagrelor plus aspirin or clopidogrel plus aspirin after a primary hospitalization for AMI between July 1, 2013, and December 31, 2018, were included. Inverse probability of treatment weighting was applied to balance covariates between treatment groups. The primary effectiveness outcome included a composite measure of AMI, acute ischemic stroke, or all-cause mortality. The primary safety outcome included a composite measure of intracranial hemorrhage (ICH) and major gastrointestinal bleeding. The secondary effectiveness and safety outcomes comprised each of the individual components that make up the primary effectiveness and safety outcomes, respectively. Results: A total of 1691 eligible patients were included in the study, of whom 734 (43.4%) received ticagrelor plus aspirin and 957 received clopidogrel plus aspirin. There were no significant differences observed in the primary and secondary effectiveness outcomes between the two study groups. However, the use of ticagrelor was associated with a higher risk of ICH (ticagrelor: 8.68 per 1000 person-year; clopidogrel: 2.17 per 1,000 person-year; HR, 3.34; 95% CI, 1.27 to 8.81, P = .01) compared with clopidogrel. Conclusion: In AMI patients with a history of acute ischemic stroke, the risks of cardiovascular events were comparable between ticagrelor plus aspirin and clopidogrel plus aspirin. However, ticagrelor was associated with a higher risk of ICH. Ticagrelor should be used cautiously in AMI patients with a history of acute ischemic stroke.