CYP2C19 pharmacogenetics versus standard of care dosing for selecting antiplatelet therapy in patients with coronary artery disease: A meta-analysis of randomized clinical trials.

OBJECTIVES: This study aimed to evaluate the efficacy and safety of personalized genotype-guided selection of antiplatelet therapy versus standard of care in patients undergoing percutaneous coronary intervention (PCI).

BACKGROUND: Clopidogrel is the most frequently used P2Y12 receptor antagonist in patients with coronary artery disease. However, genetic variations of clopidogrel are associated with inter-individual response variability which could limit its efficacy.

METHODS: Electronic databases were searched for all randomized clinical trials (RCTs) evaluating genotype-guided therapy versus standard of care in patients undergoing stent implantation. Aggregated risk ratios (RRs) and 95% CIs were calculated using a random-effects model.

RESULTS: We included 6 RCTs with a total of 2,371 patients. When compared with standard of care, the use of genotype-guided therapy did not significantly reduce major adverse cardiovascular events (MACE) (RR 0.67; 95% CI: 0.35-1.27; P = 0.22). However, MACE was significantly reduced in the subset of trials which enrolled only acute coronary syndromes (ACS) (P < 0.01). In addition, there was a significant reduction in myocardial infarction in the genotype-guided group (RR 0.44; 95% CI: 0.28-0.70; P < 0.01; I2 = 0%). Other clinical outcomes were not significantly different: cardiovascular mortality (RR 0.68; 95% CI: 0.27-1.74; P = 0.42), stroke (RR 0.62; 95% CI: 0.23-1.65; P = 0.34), stent thrombosis (RR 0.37; 95% CI: 0.13-1.06; P = 0.06), and bleeding (RR 0.68; 95% CI: 0.43-1.06; P = 0.09).

CONCLUSION: In patients undergoing stent implantation, MACE with genotype-guided therapy was not significantly reduced; however, there was a signal towards reduction of MACE in ACS patients, as well as a lower rate of MI, though this will require further confirmation in adequately powered trials.