Effect of Homocysteine-Lowering B Vitamin Treatment on Angiographic Progression of Coronary Artery Disease: A Western Norway B Vitamin Intervention Trial (WENBIT) Substudy

Total plasma homocysteine (tHcy) is an independent risk factor for coronary artery disease, and tHcy is lowered by B vitamins. To assess the effect of homocysteine-lowering B-vitamin treatment on angiographic progression of coronary artery disease, this substudy of the Western Norway B Vitamin Intervention Trial (WENBIT) included patients who had undergone percutaneous coronary intervention. The patients were randomized to daily oral treatment with folic acid, vitamin B-12, and vitamin B-6 or placebo in a 2 x 2 factorial design. The coronary angiograms obtained at baseline and follow-up were evaluated. The primary angiographic end points were the changes in minimum lumen diameter and diameter stenosis. A total of 348 subjects (288 men) with a mean +/- SD age of 60 +/- 10.2 years were followed up for a median of 10.5 months (twenty-fifth, seventy-fifth percentile 9.2, 11.8). The baseline median plasma tHcy level was 10.0 mu mol/L (twenty-fifth, seventy-fifth percentile 8.1, 11.0), and treatment with folic acid/vitamin B-12 lowered the tHcy levels by 22%. At follow-up, we found 309 lesions with a significant decrease from baseline in the minimum lumen diameter of a mean of -0.16 +/- 0.4 mm and an increase in the diameter stenosis of 4.4 +/- 0.7%. Treatment with folic acid/vitamin B-12 or vitamin B-6 was not associated with a change in diameter stenosis or minimum lumen diameter. In a post hoc analysis, folic acid/vitamin B-12 treatment was significantly associated with rapid progression (odds ratio 1.84, 95% confidence interval 1.07 to 3.18). In conclusion, vitamin B treatment showed no beneficial effect on the angiographic progression of coronary artery disease, and the post hoc analyses suggested that folic acid/vitamin B-12 treatment might promote more rapid progression. (C) 2010 Elsevier Inc. All rights reserved. (Am J Cardiol 2010;105:1577-1584)