Carriage of Cytochrome 2C19 Polymorphism Is Associated With Risk of High Post-Treatment Platelet Reactivity on High Maintenance-Dose Clopidogrel of 150 mg/day Results of the ACCEL-DOUBLE (Accelerated Platelet Inhibition by a Double Dose of Clopidogrel According to Gene Polymorphism) Study

Abstract

Objectives This study sought to determine the impact of gene polymorphisnns on platelet reactivity (PR) after clopidogrel 150 mg/day in patients treated with percutaneous coronary intervention (PCI). Background Although high maintenance-dose (MD) clopidogrel reduces PR, it is unknown whether gene polymorphisms are related with the risk of high post-treatment PR (HPPR) after high-MD clopidogrel. Methods We included mostly patients receiving high-MD clopidogrel after PCI from previously registered Gyeongsang National University Hospital data. A total of 126 PCI-treated patients receiving high-MD clopidogrel were enrolled. Platelet reactivity was assessed with conventional aggregometry and Verify Now (Accumetrics Inc., San Diego, California) after receiving clopidogrel 150 mg/day for at least 1 month. CYP3A5, CYP2C19, and ABCB1 genotyping was performed. We defined HPPR as 5 mu mol/l adenosine diphosphate (ADP) induced maximal PR (PR(max)) > 50%. Results CYP3A5 and ABCB1 polymorphisms did not influence PR. Carriers of CYP2C19 variant (*2 or *3) (n = 80) had significantly higher 5 and 20 mu mol/l ADP-induced PR than did noncarriers (n = 46) (40.7 +/- 16.8% vs. 30.3 +/- 12.6%, p < 0.001; 54.2 +/- 16.2% vs. 40.5 +/- 15.8%, p < 0.001, respectively). Late PR and Verify Now results indicated consistently greater measures in carriers versus noncarriers of CYP2C19 variant. All platelet measures proportionally increased according to the number of CYP2C19 variant alleles. Twenty-seven (21.4%) patients met the criteria for HPPR. Prevalence of HPPR was 8.7%, 21.7%, and 50.0% in carriers of 0, 1, and 2 CYP2C19 variant alleles, respectively (p < 0.001). By multivariate analysis, carriage of CYP2C19 variant was a significant predictor of HPPR (odds ratio: 5.525, 95% confidence interval: 1.333 to 23.256, p = 0.018). Conclusions Among PCI-treated patients receiving high-MD clopidogrel, carriage of CYP2C19 variant relates to increased PR and predicts risk of HPPR. (Adjunctive Cilostazol Versus High Maintenance-dose ClopidogrEL in Acute Myocardial Infarction [AMI] Patients According to CYP2C19 Polymorphism [ACCELAMI2C19]; NCT00915733; and Comparison of Platelet Inhibition With Adjunctive Cilostazol Versus High Maintenance-Dose Clopidogrel According to Hepatic Cytochrome 2C19 Allele (CYP2C19) Polymorphism [ACCEL2C19]; NCT00891670). (J Am Coll Cardiol Intv 2010;3:731-41) (c) 2010 by the American College of Cardiology Foundation