Effectiveness and Safety of Clopidogrel vs Aspirin in Elderly Patients With Ischemic Stroke

To evaluate the risks of recurrent stroke and major bleeding events with clopidogrel and aspirin use among patients aged 80 years or older. This retrospective cohort study was conducted using the Full Population Data of the Health and Welfare Database in Taiwan. Patients aged 80 years or older who received monotherapy with clopidogrel or aspirin following hospitalization for primary acute ischemic stroke between January 1, 2009, and December 31, 2018, were included. Inverse probability of treatment weighting was used to balance measured covariates between clopidogrel and aspirin users. Measured outcomes included recurrent acute ischemic stroke, acute myocardial infarction, composite cardiovascular events (recurrent stroke or acute myocardial infarction), intracranial hemorrhage, major gastrointestinal tract bleeding, and composite major bleeding events (intracranial hemorrhage or major gastrointestinal tract bleeding). A total of 15,045 patients were included in the study, 1979 of whom used clopidogrel and 13,066 who used aspirin following hospitalization for primary acute ischemic stroke. Clopidogrel use was associated with significantly lower risk of recurrent acute ischemic stroke (hazard ratio [HR], 0.89; 95% CI, 0.83 to 0.96; P=.002), composite cardiovascular events (HR, 0.88; 95% CI, 0.82 to 0.95; P