Abstract 4309: Platelet Response to Clopidogrel Assessed by a Point-of-Care Assay Predicts Myocardial Necrosis After Elective Percutaneous Coronary Intervention
Background. Suboptimal response to clopidogrel is associated with recurrent ischemic events after percutaneous coronary intervention (PCI) as consequence of residual high platelet reactivity (HPR). Yet, it is still controversial whether HPR might also have an impact on immediate PCI outcome. Therefore, we aimed at assessing the impact of HPR on peri-procedural myocardial necrosis.
Methods. We prospectively enrolled 250 biomarker negative patients loaded with 600 mg clopidogrel undergoing elective PCI. Platelet reactivity was assessed before PCI by the point-of-care VerifyNow P2Y12 assay. HPR was defined as P2Y12 reaction units (PRU) ≥240 after clopidogrel. Myocardial necrosis was assessed by cardiac biomarkers creatine kinase-MB (CK-MB) and by troponin I (Tn-I) elevation after PCI.
Results. HPR was found in 78 (31%) patients. Diabetes was more frequent among HPR patients. Body mass index and multivessel disease tended also to be more frequent in patients with HPR. Compared with subjects presenting optimal clopidogrel response, HPR patients presented higher CK-MB (>ULN: 35% vs. 20%, p=0.011; >3xULN: 13% vs. 4%, p=0.012; >5xULN: 6% vs. 2%, p=0.020) and Tn-I elevation >3xULN (32% vs. 18%, p=0.019). Mean post-procedural peak values of cardiac biomarkers were significantly higher in pts with HPR (CK-MB: 5.34±7.32 vs. 3.48±6.14 ng/ml, p=0.038; Tn-I: 0.35±0.72 vs.0.15±0.47, p=0.027). By multivariate analysis, HPR was an independent predictor of myonecrosis (OR 2.88, 95%CI 1.03– 8.03, p=0.043).
Conclusions. High platelet reactivity after clopidogrel is an independent predictor of unfavorable immediate PCI outcome as it is significantly associated with peri-procedural myocardial necrosis.