The variability of platelet response to aspirin and clopidogrel: revisiting the Caprie, Cure, Credo, and Match trials.

In a significant number of patients, platelets do not respond to aspirin and/or clopidogrel. Furthermore, this lack of response has recently been shown to affect cardiovascular outcome. At the time of the CAPRIE, CURE, CREDO, and MATCH studies, no in vitro assessment was made to determine platelet response. In vitro platelet response should be considered as an important correctable risk factor for atherosclerotic events.