Author Affiliations: School of Medicine, University of Maryland, Baltimore (firstname.lastname@example.org).
To the Editor: The recent meta-analysis by Dr Holmes and colleagues1 concluding that CYP2C19 genotype is not a significant predictor of clinical outcomes in patients treated with clopidogrel contrasts with a previous meta-analysis2 and a large body of pharmacokinetic and pharmacodynamic evidence,3 including a genome-wide association study.4 The authors cite small-study bias and inability to evaluate effect modification in treatment-only studies as reasons underlying the discrepant findings.
Shuldiner AR, Vesely MR, Fisch A. CYP2C19 Genotype and Cardiovascular Events. JAMA. 2012;307(14):1482-1485. doi:10.1001/jama.2012.443