Abstract 4000: Prognostic Significance Of Low Response To Clopidogrel Assessed By A Point-of-care Assay On Thrombotic Events Within 6 Month Follow-up After Drug-eluting Stent Implantation In Patients With Acute Coronary Syndrome
Background: Recent evidences suggested that low response or resistance to clopidogrel is associated with recurrent atherothrombotic events after drug eluting stent (DES) implantations. Acute coronary syndrome is a well-known predictor of stent thrombosis (ST) or cardiac death. We prospectively evaluated the association between low response to clopidogrel assessed by VerifyNow P2Y12 assay (Accumetrics Inc, CA) and ST or cardiac death after DES implantation in patients with acute coronary syndrome.
Methods: We enrolled consecutive 237 patients (160 males, 65.2±10.3 years) with acute coronary syndrome and DES implantations. Low response to clopidogrel was defined as the less than 20% inhibition of P2Y12 receptor assessed by VerifyNow P2Y12 assay. The composite endpoint was defined to cardiac death or ST by definitions of the Academic Research Consortium within 6 months after the index procedure.
Results: Baseline demographic characteristics were similar between normal response (142 cases) and low response (95 cases) group to clopidogrel. Patients with low response group had higher rates of cardiac death (2.1 vs. 0.7%, p =0.344), stent thrombosis (4.2 vs. 0%, p=0.014) and the combined endpoint (6.3 vs. 0.7%, p = 0.012). The univariate logistic regression shows the hazard ratio for composite endpoint was 9.65 (95% CI; 1.14 – 81.68) for low response to clopidogrel and 6.67 (95% CI; 1.25–35.54) for diabetes. After adjustment for age, sex, body mass index and diabetes, low response to clopidogrel is only predictor of composite endpoint (hazard ratio: 9.38, 95% CI; 1.08 – 81.88).
Conclusion: Low response to clopidogrel assessed by VerifyNow P2Y12 assay is an independent predictor of ST and cardiac death in patients with acute coronary syndrome and DES implantations.