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

• We examine the platelet reactivity PRU and %INH in ACS patients undergoing PCI.
• We investigate the value of COP-INH (COmbination of PRU and %INH) for prognosis.
• COP-INH = 2 (both elevated PRU and decreased %INH) was independent predictor of MACE.
• COP-INH is more useful than either PRU or %INH for predicting long term prognosis.

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 30 days 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 1 year 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.