Schnyder G, Roffi M, Flammer Y, Pin R, Hess OM.
A prospective, randomized, placebo-controlled, double-blind study (n=553) was conducted to evaluate the impact onclinical outcomes of homocysteine-lowering therapy with vitamins B12, B6, and folic acid in patients who have undergone coronary angioplasty, and to determine whether any change in outcomes persists 6 months after cessation of therapy. Patients included in the study had undergone successful angioplasty of at least 1 coronary stenosis of > or = 50% from May 1998 to April 1999.
Participants received a random assignment to either placebo (n=281) or active therapy (n=272), which consisted of 1 mg/day of folic acid, 400 micrograms/day of vitamin B12, and 10 mg/day of vitamin B6. During the study period, patients were asked to suspend use of multivitamins.
Endpoints examined at 6 months and 1 year were death, cardiac death, nonfatal myocardial infarction, repeat revascularization, and a composite of these events. The 2 patient groups were similar with regard to baseline and clinical characteristics. Results indicated that at follow-up (mean of 11 months), 9.9% (27) of active therapy patients versus 16.0% (45) of placebo patients had repeat target lesion revascularization (relative risk [RR] 0.62; 95% confidence interval [CI], 0.40-0.97; P=0.03). The composite endpoint rate was also significantly lower in the active therapy group compared to the placebo group (15.4% versus 22.8%; RR 0.68; 95% CI, 0.48-0.96; P=0.01).
Additionally, the rates of cardiac mortality, nonfatal myocardial infarction, and overall mortality were lower in the active group, though these trends were not significant. At both 6 months and 1 year, there were significantly more adverse events reported in the placebo group than in the treatment group (P=0.02 and P=0.03, respectively).
CONCLUSION: The authors conclude that their findings provide evidence of improved clinical outcomes at 6 months, including a reduction in the need for target lesion revascularizaton, when successful coronary intervention is followed by therapy with folic acid and vitamins B6 and B12*; and that this homocysteine-lowering therapy's benefits persist for up to a year despite cessation of therapy.
*The vitamin B12 avoids missing pernicious anemia masked by the use of high dose folate in these patients.