ABCB1 C3435T polymorphism and risk of adverse clinical events in clopidogrel treated patients: A meta-analysis

Abstract Introduction The ABCB1 C3435T polymorphism limits oral bioavailability of clopidogrel and may influence prognosis of patients treated with clopidogrel. Several studies have examined the association between the C3435T polymorphism and risk of adverse clinical events in clopidogrel treated patients, but the results were inconsistent. To assess the role of the C3435T polymorphism in the impact on clinical outcomes, a meta-analysis was conducted. Methods 6 studies with 10,153 subjects were included in this meta-analysis. Fixed- or random-effects model was chosen according to heterogeneity. Publication bias was evaluated by fail-safe numbers. Results The association of the C3435T polymorphism with risk of overall recurrent ischemic events in clopidogrel treated patients was not statistically significant for all genetic models (OR = 1.13, 95%CI: 0.78–1.64, P = 0.51; OR = 1.15, 95%CI: 0.99–1.33, P = 0.07; OR = 1.19, 95%CI: 0.81–1.76, P = 0.37). Significant association was identified between the C3435T polymorphism and risk of short-term recurrent ischemic events (OR = 1.55, 95% CI: 1.09-2.20, P = 0.01; OR = 1.41, 95% CI: 1.06-1.87, P = 0.02; OR = 1.77, 95% CI: 1.19-2.63, P = 0.005). No statistically significant association between the C3435T polymorphism and stent thrombosis (OR = 0.79, 95% CI: 0.47-1.32, P = 0.37) or bleeding (OR = 0.98, 95% CI: 0.79-1.21, P = 0.82) was identified. The results may be affected by publication bias. Conclusions This meta-analysis failed to show an association between the ABCB1 C3435T polymorphism and risk of overall recurrent ischemic events, stent thrombosis or bleeding in clopidogrel treated patients. However, the association between TT homozygotes of the C3435T polymorphism and risk of short-term recurrent ischemic events may exist, but needs more studies to confirm.