Effect of homocysteine-lowering therapy with folic acid, vitamin B(12),
and vitamin B(6) on clinical outcome after percutaneous coronary intervention:
the Swiss Heart study: a randomized controlled trial.
Schnyder G; Roffi M; Flammer Y; Pin R; Hess OM
Journal of the American Medical Association 2002 Aug 28;288(8):973-9
CONTEXT: Plasma homocysteine level has been recognized as an important
cardiovascular risk factor that predicts adverse cardiac events in patients
with established coronary atherosclerosis and influences restenosis rate
after percutaneous coronary intervention. OBJECTIVE: To evaluate the effect
of homocysteine-lowering therapy on clinical outcome after percutaneous
coronary intervention. DESIGN, SETTING, AND PARTICIPANTS: Randomized,
double-blind placebo-controlled trial involving 553 patients referred
to the University Hospital in Bern, Switzerland, from May 1998 to April
1999 and enrolled after successful angioplasty of at least 1 significant
coronary stenosis (> or = 50%). INTERVENTION: Participants were randomly
assigned to receive a combination of folic acid (1 mg/d), vitamin B(12)
(cyanocobalamin, 400 micro g/d), and vitamin B(6) (pyridoxine hydrochloride,
10 mg/d) (n = 272) or placebo (n = 281) for 6 months. MAIN OUTCOME MEASURE:
Composite end point of major adverse events defined as death, nonfatal
myocardial infarction, and need for repeat revascularization, evaluated
at 6 months and 1 year. RESULTS: After a mean (SD) follow-up of 11 (3)
months, the composite end point was significantly lower at 1 year in patients
treated with homocysteine-lowering therapy (15.4% vs 22.8%; relative risk
[RR], 0.68; 95% confidence interval [CI], 0.48-0.96; P =.03), primarily
due to a reduced rate of target lesion revascularization (9.9% vs 16.0%;
RR, 0.62; 95% CI, 0.40-0.97; P =.03). A nonsignificant trend was seen
toward fewer deaths (1.5% vs 2.8%; RR, 0.54; 95% CI, 0.16-1.70; P =.27)
and nonfatal myocardial infarctions (2.6% vs 4.3%; RR, 0.60; 95% CI, 0.24-1.51;
P =.27) with homocysteine-lowering therapy. These findings remained unchanged
after adjustment for potential confounders. CONCLUSION: Homocysteine-lowering
therapy with folic acid, vitamin B(12), and vitamin B(6) significantly
decreases the incidence of major adverse events after percutaneous coronary
intervention.
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