Prediction of clopidogrel efficacy and safety: phenotyping and/or genotyping?

In patients undergoing percutaneous coronary intervention the role of platelet function assessment (phenotyping) while on-clopidogrel and/or genotyping for outcome prediction is being intensively investigated. The study under evaluation reported the diagnostic accuracy of phenotyping versus genotyping for prediction of ischemic and bleeding events in 416 such patients during 1-year follow-up. Their data shows that the phenotyping of platelet response to clopidogrel by multiple electrode aggregometry was a better predictor of stent thrombosis than other platelet function assays used and even genotyping for the CYP2C19*2 allele. The authors recognize that it is premature to recommend any assay to guide the antiplatelet treatment in routine clinical practice. However, the need for properly powered randomized trials to address this issue is emphasized.