Platelet aggregation and the risk of stent thrombosis or bleeding in elective percutaneous coronary intervention patients.

: Platelet aggregation monitoring in patients after stent implantation is a promising way of preventing stent thrombosis and bleeding. The aim of the study was to verify whether clopidogrel (ADPtest) and aspirin (ASPItest) response measured by Multiplate (Dynabyte, Munich, Germany) analyzer in elective percutaneous coronary implantation patients predict the risk of stent thrombosis or other ischemic adverse events and bleeding. In this prospective, observational study 697 elective percutaneous coronary implantation patients were analyzed. The median ASPItest was 86 AU min. In 69 patients (9.9%), an ASPI result of more than 203 AU min was observed. The median ADP-dependent platelet aggregation was 212 AU min. In 36 (5.2%) patients, the result was at least 468 AU min. Cox regression analysis showed the prognostic factors of definite or probable stent thrombosis and cardiac death at 1 year were higher ASPItest result [odds ratio (OR) 1.006, 95% confidence interval (CI) 1.004-1.008, P < 0.001], ASPItest more than 203 AU min (OR 7.61, 95% CI 2.83-20.43, P < 0.001), higher ADPtest result (OR 1.005, 95% CI 1.003-1.007, P < 0.001) and ADPtest at least 468 AU min (OR 12.54, 95% CI 4.56-35.53, P < 0.001). In turn, ADPtest 188 AU min or less predicted GUSTO scale major and moderate bleeding (OR 4.15, 95% CI 1.12-15.32, P = 0.033). There was also a strong trend toward higher rate of major and moderate bleeding for the ASPItest less than 35 AU min (lowest quintile) - (OR 3.04, 95% CI 0.96-9.58, P = 0.058). Lower creatinine clearance and lower hemoglobin level were associated with both ischemic and bleeding complications. The results of this study show that impaired platelet response to clopidogrel and aspirin measured by the Multiplate analyzer results in increased risk of stent thrombosis and cardiac death. Furthermore, the study showed that increased response to clopidogrel is related to major and moderate bleeding events.