Comparative Benefits of Clopidogrel and Aspirin in High-Risk Patient Populations

Clopidogrel has been evaluated in clinical trials that included cardiovascular patients with different risk levels for a cardiovascular event. We reviewed the results of the Clopidogrel vs Aspirin in Patients at Risk of Ischemic Events (CAPRIE) and Clopidogrel in Unstable Angina to Prevent Recurrent Events (CURE) trials, with special emphasis on comparing the outcomes in high-risk patients with those of the total populations in the trials. The results in the high-risk subgroups and total populations were compared by recording total event rates, absolute risk reduction, relative risk reduction, and number needed to treat. In the CAPRIE trial, the efficacy of clopidogrel was compared with acetylsalicylic acid (ASA) in the following subgroups: total population, previous coronary bypass surgery, history of more than 1 ischemic event, multiple vascular beds involvement, diabetes, and hypercholesterolemia. In the CURE trial, the combination of clopidogrel and ASA was compared with ASA alone. The results in the CURE study were compared in patients who did and did not have a coronary intervention procedure, in patients with different levels of risk based on the Thrombolysis in Myocardial Infarction score and in patients with and without a history of a revascularization procedure. High-risk subgroups of patients participating in the CAPRIE and CURE studies were more responsive to the beneficial effects of clopidogrel compared with the study population as a whole. High-risk groups in the CAPRIE and CURE studies would be expected to derive enhanced benefit from treatment with clopidogrel over that achieved by ASA.