Impact of CYP2C19 genotype status on clinical outcomes in patients with symptomatic coronary artery disease, stroke, and peripheral arterial disease

Abstract

Abstract Background Coronary artery disease (CAD), stroke, and peripheral arterial disease (PAD) are clinical manifestations of atherosclerosis. Clopidogrel is widely used for the secondary prevention of atherothrombotic events in these patients. CYP2C19 plays a pivotal role in the conversion of clopidogrel to its active metabolite. Clopidogrel-treated carriers of a CYP2C19 loss-of-function allele (LOF) may have a higher risk of new atherothrombotic events. Previous studies on genotype-guided treatment were mainly performed in CAD and showed mixed results. Purpose To simultaneously investigate the impact of CYP2C19 genotype status on the rate of atherothrombotic events in the most common types of atherosclerotic disease (CAD, stroke, PAD). Methods A comprehensive search in Pubmed, EMBASE and MEDLINE from their inception to April 8th 2022 was performed. For CAD, randomized controlled trials (RCTs) comparing genotype-guided and standard antithrombotic treatment were included. For stroke and PAD, cohort studies and post-hoc analyses of RCTs concerning the association between CYP2C19 genotype status and clinical outcomes in clopidogrel-treated patients were included. The primary efficacy endpoint was major adverse cardiovascular events (MACE) and the safety end point major bleeding. Secondary endpoints were myocardial infarction, stent thrombosis, and ischemic stroke. Results Forty-two studies were identified: 11 studies on CAD, 27 studies on stroke, and 4 studies on PAD. In CAD, genotype-guided therapy significantly reduced the risk of MACE (RR 0.60, 95% CI 0.43 – 0.83), myocardial infarction (RR 0.53, 95% CI 0.42 – 0.68), and stent thrombosis (RR 0.64, 95% CI 0.43 – 0.94) compared to standard antithrombotic treatment. The rate of major bleeding did not differ significantly (RR 0.93, 95% CI 0.70 – 1.23). Most RCTs were performed in patients after percutaneous coronary intervention (9/11). In stroke, LOF carriers had a significantly higher risk of MACE (RR 1.62, 95% CI 1.24 – 2.11) and recurrent ischemic stroke (RR 2.00, 95% CI 1.49 – 2.67) compared to non-carriers. No significant differences were found in major bleeding (RR 0.90, 95% CI 0.43 – 1.89). In the 6955 patients with symptomatic PAD treated with clopidogrel in the EUCLID trial, no differences in MACE or major bleeding were found between LOF carriers and non-carriers. In three smaller studies on patients with PAD treated with clopidogrel after endovascular therapy, CYP2C19 genotype status was significantly associated with atherothrombotic events. Conclusion The available evidence in PAD is too limited to draw meaningful conclusions. In stroke patients, LOF carriers treated with clopidogrel had a higher risk of MACE and recurrent stroke. Genotype-guided treatment significantly decreased the rate of atherothrombotic events in patients with CAD, especially after PCI.