A randomized pilot trial for aggressive therapeutic approaches in aspirin-resistant patients undergoing percutaneous coronary intervention

Abstract

Background: There is great variability among individual patients in platelet inhibition after aspirin intake. Aspirin resistance has been associated with a higher incidence of ischemic events after percutaneous coronary intervention (PCI). The optimal antiplatelet therapy in aspirin-resistant patients undergoing PCI is unknown. The objective of this study was to evaluate whether aggressive antiplatelet therapy would reduce ischemic events in aspirin-resistant patients after PCI.

Methods: A total of 330 patients undergoing PCI (with bivalirudin) were screened for aspirin responsiveness. The resulting 36 aspirin-resistant patients were randomized into two arms: 1) conventional strategy patients received 325 mg aspirin orally and a loading dose of 600 mg clopidogrel at the time of the procedure; and 2) aggressive strategy patients received similar amounts of aspirin and clopidogrel, with the addition of an intravenous glycoprotein IIb/IIIa inhibitor bolus intraprocedurally. The primary outcome was an elevation of cardiac enzymes within 24 hours post procedure. The secondary outcome was a composite of major adverse cardiac events including death, myocardial infarction, stent thrombosis and urgent revascularization, and bleeding up to 30 days.

Results: Primary outcome occurred in 22% of the conventional strategy group and 11% of the aggressive strategy group (p = 0.36). The secondary outcome was reached in 27.8% of the conventional group and 5.5% of the aggressive strategy group (p = 0.17), which is suggestive of a statistical trend toward more ischemic events with conventional therapy. Importantly, there were 2 cases of definite stent thrombosis in the conventional strategy group.

Conclusion: In aspirin-resistant patients, aggressive antiplatelet therapy tended to show better outcomes after PCI, without an increase in bleeding. These findings need validation in a large, randomized study.