L. H. Cavallari, O. Magvanjav, R. David Anderson, A. Owusu-Obeng, B. Kong, T. Vo, J. N. Ashton, B. J. Staley, A. R. Elsey, R. M. Cooper-Dehoff, K. W. Weitzel, M. J. Clare-Salzler, D. R. Nelson, J. A. Johnson; University of Florida, Gainesville, FL

BACKGROUND: Clopidogrel is bioactivated by CYP2C19, and data show reduced clopidogrel effectiveness with the CYP2C19 loss-of-function (LOF) genotype, especially after percutaneous coronary intervention (PCI) and stent placement. We examined whether clinical implementation of CYP2C19 genotype-guided antiplatelet therapy (APT) reduces the risk for major adverse cardiovascular events (MACE) after PCI.
METHODS: CYP2C19 genotyping post-PCI was implemented at University of Florida Health Shands Hospital in July 2012, with alternative APT recommended for LOF allele carriers. Patient characteristics and MACE at 30 days per medical record review were compared between LOF allele carriers switched or not switched to alternative APT and between LOF allele carriers switched to alternative APT and non-LOF allele carriers using the Student’s unpaired t-test or Fisher’s exact test. Collection of 30-day outcomes was completed in September 2014.
RESULTS: A total of 297 patients genotyped through August 2014 had follow-up data. Baseline characteristics were similar between LOF allele carriers with or without an APT change. In LOF allele carriers, switching to alternative APT resulted in less MACE (figure).
CONCLUSION: Clinical implementation of CYP2C19-guided APT for patients undergoing PCI is associated with reduced occurrence of MACE at 30 days.