Aspirin treatment and outcomes after percutaneous coronary intervention: Results of the ISAR-ASPI registry

Background Aspirin administration, as part of a dual antiplatelet treatment regimen, is essential for patients undergoing percutaneous coronary intervention (PCI). Although the correlation between high on-clopidogrel treatment platelet reactivity (HCPR) and clinical outcome is well established, data for high on-aspirin treatment platelet reactivity (HAPR) are conflicting. Objectives The aim of the ISAR-ASPI (Intracoronary Stenting and Antithrombotic Regimen - ASpirin and Platelet Inhibition) registry was to assess the value of HAPR as a possible prognostic biomarker in PCI-treated patients with regard to clinical outcome. Methods From February 2007 to May 2013, we identified 7,090 consecutive PCI-treated patients with measured on-aspirin treatment platelet aggregation values directly before PCI. Platelet function was assessed with a Multiplate analyzer. The primary endpoint was death or stent thrombosis (ST) at 1 year. Results The upper quintile of patients (n = 1,414), according to Multiplate measurements, was defined as the HAPR cohort. Compared with non-HAPR patients (n = 5,676), HAPR patients showed a significantly higher risk of death or ST at 1 year (6.2% vs. 3.7%, respectively; odds ratio [OR]: 1.78; 95% confidence interval [CI]: 1.39 to 2.27; p < 0.0001). HAPR was found to be an independent predictor of the primary outcome (adjusted hazard ratio [HR _adj]: 1.46; 95% CI: 1.12 to 1.89; p = 0.005). Conclusions HAPR, measured at the time point of the PCI, is associated with a higher risk for death or ST during the first year after PCI. Present data are in support of the addition of HAPR to a panel of prognostic biomarkers in PCI-treated patients.