Objectives: The purpose of this study was to evaluate the effects of aspirin and clopidogrel response on myonecrosis after percutaneous coronary intervention (PCI) with glycoprotein (GP) IIb/IIIa blockade.
Background: Aspirin and clopidogrel resistance is increasingly recognized, but its effects on PCI outcomes with GP IIb/IIIa blockade are unknown.
Methods: This was a prospective, pre-specified substudy of the BRIEF-PCI (Brief Infusion of Intravenous Eptifibatide Following Successful Percutaneous Coronary Intervention) trial, which randomized 624 patients to 18-h or <2-h eptifibatide infusion after uncomplicated PCI. To be eligible, patients must have been pre-treated with aspirin (>or=5 days) and clopidogrel (75 mg/day >or=5 days, 300 mg loading >or=6 h, or 600 mg loading >or=2 h) and must not have received GP IIb/IIIa inhibitors within 48 h. Verify-Now Aspirin and Clopidogrel (P2Y(12)) assays were performed at baseline before PCI. Patients with aspirin reaction unit (ARU) >or=550 were labeled as aspirin resistant. Clopidogrel low-responders were defined as those in the lowest quartile of platelet inhibition. The primary end point was the prevalence of myonecrosis within 24 h after PCI.
Results: We enrolled 209 patients into our substudy, of which 185 had aspirin response assessed, 198 had clopidogrel response assessed, and 174 had both assessed. There were 4.9% who were aspirin resistant. Clopidogrel low-responders were defined as those in the lowest quartile with platelet inhibition <19%. Only 1.1% had both aspirin resistance and low clopidogrel response. There was no difference in myonecrosis prevalence among aspirin-resistant compared with aspirin-sensitive patients (11.1% vs. 27.8%, p = 0.259) or among clopidogrel low-responders compared with clopidogrel responders (23.5% vs. 29.3%, p = 0.433).
Conclusions: Aspirin and clopidogrel response did not affect myonecrosis prevalence amongst patients who received eptifibatide for PCI.