Abstract TP411: Effects of Triflusal and Clopidogrel in Secondary Prevention of Stroke Based on Cytochrome P450 2C19 Genotyping

Abstract

Background: The relationship between stroke recurrence and cytochrome P450 2C19 (CYP2C19) genotype for the secondary prevention of ischemic stroke (IS) is not clearly defined. We investigated the effect of antiplatelet agents based on CYP2C19 genotype in secondary prevention of IS. Methods: In this prospective, multicenter, randomized, parallel-group, open-label, and blind genotype trial, we enrolled first non-cardiogenic IS patients within 30 days prior to screening at the 18 tertiary-care hospitals. Participants received 300 mg triflusal twice a day or 75 mg clopidogrel once daily. CYP2C19 genotyping was done in all patients and genotype results were blind during the study. The primary outcome was the time from randomization to first recurrent IS or hemorrhagic stroke. Efficacy analyses were performed using both the modified intention-to- treat population and the per-protocol population. The study is registered with ClinicalTrials.gov (NCT01174693). Results: This trial failed to meet its recruitment goal due to slow enrollment. A total of 784 (73% of required sample size) patients were followed for a mean of 2.5 years. In poor CYP2C19 genotype group (n=484), 30 (6.2%) patients had a recurrent stroke. The risk of recurrent stroke in triflusal group was 2.9% per year and was not significantly different with clopidogrel group (2.2% per year; hazard ratio [HR], 1.23; 95% confidence interval [CI], 0.6 to 2.53). In clopidogrel treatment group (n=393), 20 (5.1%) had a recurrent stroke. The risk of recurrent stroke in good CYP2C19 genotype was 1.6% per year and was not significantly different with poor genotype (2.2% per year; HR, 0.69; 95% CI, 0.26 to 1.79). Conclusions: In poor CYP2C19 genotype group, either triflusal or clopidogrel was not superior to the other in the prevention of recurrent stroke.