Prior aspirin use predicts worse outcomes in patients with non-ST-elevation acute coronary syndromes

Aspirin is beneficial in the prevention and treatment of cardiovascular eve nts, but patients who have events while taking aspirin may have worse outco mes than those not on aspirin. We investigated the association between prio r aspirin use and clinical outcomes in 9,461 patients with non-ST-elevation acute coronary syndromes enrolled in the Platelet IIb/IIIa in Unstable ang ina: Receptor Suppression Using Integrilin Therapy (PURSUIT) trial, before and after adjustment for baseline factors. We also examined whether eptifib atide has a differential treatment effect in prior aspirin users. Prior asp irin users were less likely to have an enrollment myocardial infarction (MI ) (vs unstable angina) (43.9% vs 48.8%, p = 0.001) but more likely to have death or MI at 30 days (16.1% vs 13.0%, p = 0.001) and at 6 months (19.9% v s 15.9%, p = 0.001). After adjustment, prior aspirin users remained less li kely to have an enrollment MI (odds ratio 0.88, 95% confidence interval 0.7 9 to 0.97) and more likely to have death or MI at 30 days (odds ratio 1.16, 95% confidence interval 1.00 to 1.33) but not at 6 months (adds ratio 1.14 , 95% confidence interval 0.98 to 1.33). In a multivariable model, eptifiba tide did not have a different treatment effect in prior aspirin users compa red with nonusers (p = 0.534). Prior aspirin users had fewer enrollment Mis but worse long-term outcomes than nonusers. We found no evidence for a dif ferent treatment effect of eptifibatide in prior aspirin users. (C)1999 by Excerpta Medica, Inc.