Impact of high on-aspirin platelet reactivity on outcomes following successful percutaneous coronary intervention with drug-eluting stents.

BACKGROUND:Whether high on-aspirin platelet reactivity (HAPR) confers an increased risk of adverse outcomes after percutaneous coronary intervention (PCI) remains unclear. We sought to examine the specific relationship between HAPR and clinical outcomes in ADAPT-DES. METHODS:A total of 8,526 "all-comer" patients in the ADAPT-DES registry who underwent placement of drug-eluting stents (DES) and were treated with aspirin and clopidogrel were assessed to measure platelet reactivity. HAPR was characterized as ≥550 aspirin reaction units and high on-clopidogrel platelet reactivity as >208 P2Y12 reaction units. Univariable and propensity-adjusted multivariable analyses were used to assess the relationship between HAPR and clinical outcomes. RESULTS:HAPR was present in 478 (5.6%) patients. Patients with HAPR were older and had more comorbid illnesses and more complex coronary anatomy. During 2-year follow-up, HAPR was not associated with increased rates of major adverse cardiac events (MACE), stent thrombosis, myocardial infarction, or all-cause mortality. In propensity-adjusted multivariable analyses, HAPR was not an independent predictor of MACE after successful PCI (multivariable adjusted hazard ratio: 1.04; 95% CI 0.64-1.69, P = .87). Nor was HAPR associated with reduced bleeding. Even among patients with concomitant high on-clopidogrel platelet reactivity, HAPR was not associated with worse ischemic outcomes (adjusted hazard ratio for 2-year MACE: 1.06; 95% CI 0.55-2.00, P = .87). CONCLUSIONS:HAPR was infrequently present in a large registry of patients undergoing PCI. There was no clear relationship between HAPR and 2-year clinical outcomes. Investigations of antiplatelet regimens without aspirin after DES implantation are ongoing and should inform future management of patients undergoing PCI.