C677T polymorphism of the methylenetetrahydrofolate reductase gene is a risk factor of adverse events after coronary revascularization

Background: A common point mutation (C677T) in the gene for 5,10-methylenetetrahydrofolate reductase (MTHFR) is associated with hyperhomocysteinemia, an independent risk factor and a strong predictor of mortality in patients with coronary artery disease (CAD). The aim of this study was to investigate whether C677T polymorphism can be a predictor of major adverse cardiac events after myocardial revascularization. Methods: We determined MTHFR genotype in 159 patients with CAD undergoing myocardial revascularization [72 percutaneous transluminal coronary angioplasty (PTCA) and 87 coronary artery bypass graft (CABG)]. Recurrent angina, nonfatal myocardial infarction (MI), target vessel revascularization, heart failure and cardiac death were considered major adverse cardiac events that occurred after discharge from index hospitalization. Results: During the follow-up (6.9 +/- 0.3 months, mean +/- S.E.M.), the composite endpoint accounted for 25.9%, 11.4% and 4.3% for TT, CT and CC genotype (log-rank statistic 5.2, p = 0.02), respectively. Subjects with mutant TT genotype had a threefold increase of any cardiac event (hazard ratio [HR] = 3.0; 95% [CI], 1.1-8.1). In multiple-variable regression Cox, predictors of events were TT genotype (HR 2.8; 95% CI 1.01-7.62,p = 0.047), low-ejection fraction < 40% (HR = 4.5; 95% CI, 1.62-12.6,p = 0.004) and revascularization procedure (HR = 6.1; 95% CI, 1.86-20.34,p = 0.003). Conclusions: These data indicate that the TT genotype seems to be significantly associated with major adverse cardiac events after myocardial revascularization in CAD patients, suggesting a potential pathological influence of homocysteine in the clinical outcome. (C) 2003 Elsevier Ireland Ltd. All rights reserved.