Genotype-guided antiplatelet management after percutaneous coronary intervention (PCI) reduces cumulative ischemic events at 1 year without a significant increase in bleeding events, according to new study findings. Brenden S. Ingraham, MD, of the Mayo Clinic, Rochester, Minnesota, presented these results from a prespecified secondary analysis of the TAILOR-PCI randomized trial Friday at the European Society of Cardiology (ESC) Congress 2022 in Barcelona, Spain. Clopidogrel is the most prescribed P2Y12 inhibitor after PCI; however, patients with the loss of function (LOF) CYP2C19 allele, which causes reduction in clopidogrel’s effects, can lead to uninhibited platelets and increased ischemic events. TAILOR-PCI was an open-label, international, randomized control trial. Patients with acute coronary syndrome (ACS) or stable coronary artery disease (CAD) who would receive 12 months of dual antiplatelet therapy were included. Notably, patients were excluded if there was a planned revascularization of any vessel in 30 days or the target vessel within 12 months. Patients who underwent point-of-care (POC)genotype guided therapy would receive ticagrelor if they were LOF carriers; otherwise, they would receive 75 mg of clopidogrel daily. Patients in the conventional-therapy arm received 75 mg of clopidogrel daily with genotyping at 12 months The original primary endpoint was time to event of the composite of cardiovascular death, myocardial infarction, severe recurrent ischemia, stent thrombosis or stroke at 12 months. For the original primary outcome, there was a relative risk reduction of 34% in the genotype guided arm, which did not meet statistical significance (p=0.056), and there was no difference in bleeding. Regarding cumulative primary endpoints, which accounts for recurrent events and was the focus of the ESC presentation, 5,276 patients were analyzed, their median age was 63 years, 25% were women, 82% had ACS, and 18% had stable CAD. There were 1,849 patients with CYP2C19 LOF. At 1 year, the genotype-guided arm had a 40% reduction in cumulative ischemic events (hazard ratio: 0.61; 95% confidence interval: 0.41-0.89; p=0.01) without any significant increase in bleeding events. When asked about the utility of genotype testing, Ingraham said, “This is a target that is pretty easy, relatively inexpensive, especially when we look at the added costs of these recurrent ischemic events, because the $200, $300 at most for this test is every easily offset by one presentation to the emergency department.” Spartan Bioscience Inc. provided the POC genotyping platform and assays used in the trial.