Genetic and platelet function testing of antiplatelet therapy for percutaneous coronary intervention: the ARCTIC-GENE study

Background The ARCTIC study randomized 2440 patients scheduled for stent implantation to a strategy of platelet function monitoring with drug adjustment in patients who had a poor response to antiplatelet therapy or to a conventional strategy without monitoring and drug adjustment. No significant improvement in clinical outcomes with platelet function monitoring was observed. Objective The purpose of this study is to assess the relationships between CYP2C19 genotypes, clopidogrel pharmacodynamic response, and clinical outcome. Methods and results In the ARCTIC-GENE study, 1394 patients were genotyped for loss- and gain-of-function CYP2C19 alleles. Randomization of treatment strategy was well balanced. Slow metabolizers identified as carriers of at least one loss-of-function allele CYP2C19*2 ( n = 459) were more likely poor responders at randomization (41.6 vs. 31.6 %, p = 0.0112) and 14 days later (23.8 vs. 10.4 %, p