Abstract 15688: Association of Cytochrome P450 2C19 Polymorphism With Ischemic and Bleeding Risk in Patients With Atrial Fibrillation Undergoing Percutaneous Coronary Intervention

Abstract

Introduction: CYP2C19 isoenzymes of cytochrome P450 impact the effect of clopidogrel. Guidelines recommend clopidogrel in addition to oral anticoagulation (OAC) in patients with atrial fibrillation (AF) after percutaneous coronary intervention (PCI). This study aimed to evaluate the association of CYP2C19 polymorphism with ischemic and bleeding risk in patients with AF undergoing PCI. Methods: Patients with AF and an indication for OAC were included in this two-center prospective cohort study up to 3 days after PCI. Carriers of ≥1 loss of function (LOF) allele CYP2C19*2 were classified as poor metabolisers (PM). Carriers of ≥1 gain of function allele (GOF) were defined as rapid metabolisers (RM). Normal metabolisers (NM) were defined as absence of LOF and GOF alleles. Primary outcome was defined as death, myocardial infarction, or stroke (MACE) at 6 months ±2 weeks. Secondary outcome was defined as non-major clinically relevant (NMCR) or major bleedings. Results: 283 patients were included in the study. Median age was 78 (interquartile range, IQR 72-82) years old and 204 (72%) were males. All patients received treatment with clopidogrel and OAC. 73 (26%) were PM, 108 (38%) were NM and 102 (36%) RM. The primary ischemic outcome occurred in 22 (8%) and the secondary outcome in 38 (13%) patients. PM status did not significantly associate with primary ischemic outcome (PM: 6 [8.2%] vs. NM+RM: 16 [7.6%]; odds ratio, OR 1.09 [95% confidence interval 0.41-2.89], p=0.805). RM status did not significantly associate with bleeding (RM: 14 [13.7%] vs. PM+NM: 24 [13.3%]; OR 1.04 [0.51-2.12], p=1.00). Bleeding rates tended to be lower for patients with PM status (major, NMCR, or minor bleeding: PM 12 [28.7%] vs. NM+RM 84 [40.0%]; 0.61 [0.34-1.07], p=0.09). Conclusions: This pilot study of patients with oral anticoagulation for atrial fibrillation and clopidogrel after PCI ruled out, with 95% confidence, a ≥3-fold increase of ischemic risk for carriers of ≥1 loss of function allele CYP2C19*2 compared with non-carriers. This study was underpowered to detect less pronounced associations. LOF-carrier status might protect from bleeding.