Combination of P2Y12 reaction unit and percentage of platelet inhibition assessed by VerifyNow P2Y12 assay is a useful predictor of long-term clinical outcomes in patients with acute coronary syndrome undergoing percutaneous coronary intervention

Abstract

IntroductionHigh on-treatment platelet reactivity is a well-known risk factor for adverse events in patients undergoing percutaneous coronary intervention (PCI). This study was to investigate the value of a novel platelet reactivity-based system, named the COP-INH (COmbination of P2Y12 reaction unit [PRU] and percentage of platelet inhibition [%INH]), assessed by VerifyNow P2Y12 assay, for predicting the long-term ischaemic events in patients with acute coronary syndrome (ACS) undergoing PCI. Materials and methodsThe COP-INH was calculated on the basis of data obtained at 30days after PCI: patients with both an elevated PRU (≥230) and decreased %INH (<40%) were allocated a score of 2, and patients showing one or neither were allocated a score of 1 or 0, respectively. The primary endpoint was the composite of cardiovascular death, nonfatal myocardial infarction, and target vessel revascularization at 1year follow-up. The relationship between the COP-INH score and primary endpoint was analyzed. Results207 patients were enrolled. Baseline characteristics were similar between patients with COP-INH=2 and patients with COP-INH=1 or 0, except for diabetes mellitus (43.8% vs. 21.7%, p=0.015) and previous coronary artery bypass grafting (CABG) (21.9% vs. 6.86%, p=0.007). During the observation period, the incidence of major adverse cardiovascular events (MACE) in patients with COP-INH=2 was significantly higher than patients with COP-INH=1 or 0 (18.8% vs. 4.6%, p=0.007). Multivariate analysis of clinical characteristics and platelet reactivity selected by univariate analysis showed that the COP-INH=2 was an independent predictor of MACE in patients with ACS undergoing PCI (OR 2.745; 95% CI 1.369-9.851; p=0.024), whereas neither PRU≥230 nor %INH<40% was. ConclusionThe COP-INH is considered to be a useful predictor of long-term ischaemic events of patients with ACS undergoing PCI.