An optimal window of platelet reactivity by LTA assay for patients undergoing percutaneous coronary intervention

Abstract Objective This study was aimed to determine how platelet reactivity (PR) on dual antiplatelet therapy predicts ischemic and bleeding events in patients underwent percutaneous coronary intervention (PCI). Design A total of 2768 patients who had received coronary stent implantation and had taken aspirin 100 mg in combination with clopidogrel 75 mg daily for > 5 days were consecutively screened and 1885 were enrolled. The recruited patients were followed-up for 12 months. The primary end-point was the net adverse clinical events (NACE) of cardiovascular death, nonfatal myocardial infarction (MI), target vessel revascularization (TVR), stent thrombosis (ST) and any bleeding. Result 1709 patients completed the clinical follow-up. By using the receiver operating characteristic (ROC) curve analysis, the optimal cut-off values were found to be 37.5 and 25.5% respectively in predicting ischemic and bleeding events. Patients were classified into 2 groups according to PR: inside the window group (IW) [adenosine diphosphate (ADP) induced platelet aggregation (PLADP) 25.5–37.4%)] and outside the window group (OW) (PLADP < 25.5% or ≥ 37.5%). The incidence of NACE was 16.8 and 23.1% respectively in the IW and OW group. The hazard ratio of NACE in IW group was significantly lower [0.69 (95% CI, 0.54–0.89, P = 0.004)] than that in the OW group during 12-month follow-up. Conclusion An optimal therapeutic window of 25.5–37.4% for PLADP predicts the lowest risk of NACE, which could be referred for tailored antiplatelet treatment while using LTA assay. Trial registration Trial registration number: ClinicalTrials.gov NCT01968499 . Registered 18 October 2013 - Retrospectively registered