Impact of high post-loading platelet aggregation on 30-day clinical outcomes after primary percutaneous coronary intervention. The antiplatelet regimen tailoring after primary PCI (ART-PCI) trial

Abstract

BackgroundPatients with high post-loading platelet aggregation (PPA) are at increased risk of stent thrombosis and death after primary percutaneous coronary intervention (pPCI). The objective of the present trial was to examine whether high PPA is associated with adverse clinical outcomes in pPCI patients whose therapy was modified in accordance with PPA. MethodsWe analyzed 961 consecutive pPCI patients who underwent pPCI between February 2008 and June 2011. High PPA was defined as PPA >50%, 24h after the loading dose. Patients with high PPA were treated with aspirin 300mg, clopidogrel 150mg or ticlopidine 500mg for 30days. The co-primary efficacy and safety end points at 30days were major adverse cardiovascular events (MACE) and major bleeding. ResultsWe detected high PPA to clopidogrel and aspirin in 44.4% and 16.5% of patients, respectively. The rates of 30-day MACE (adjusted OR 1.76, 95% CI 1.05–2.97), definite subacute stent thrombosis (DSST, adjusted OR 2.15, 95% CI 1.09–4.22) and nonfatal infarction (adjusted OR 3.99, 95% CI 1.57–10.13) were higher in patients with high PPA to clopidogrel compared with responders. High PPA to aspirin was not associated with an adverse 30-day clinical outcome. Compared with high PPA patients who were not tailored, a significantly better outcome with respect to the primary end point was observed in the tailored group (OR 0.42, 95% CI 0.19–0.93). ConclusionHigh PPA to clopidogrel was an independent predictor of 30-day adverse events after pPCI. Among high PPA patients, tailoring was associated with an improved primary outcome.