Being female was associated with increased risk for aspirin resistance.
Aspirin is a mainstay of treatment for coronary artery disease (CAD), but some patients who do not exhibit the expected antiplatelet effects are considered to have aspirin resistance. To test whether a history of clinical cardiac events predicts the likelihood of having biologic aspirin resistance, 50 CAD patients (38% women) who had experienced a myocardial infarction while on aspirin therapy (usually 81 mg/day) were compared with 50 patients (28% women) with CAD but no prior MI. Whole-blood assay of arachidonic acid-induced platelet aggregation was performed within 48 hours after patients took a dose of aspirin. Aspirin resistance was defined as <40% inhibition of arachidonic acid-mediated platelet aggregation.
History of MI was not signif…