Cardiovascular effects of B-vitamins and/or N-3 fatty acids: the SU.FOL.OM3 trial

Background: Mechanisms involved in coronary stenosis evolution are different than those involved in clinical events. Because of differential vascular effects, N-3 polyunsatured fatty acids (PUFA) and B vitamins could have differential effects on different types of cardiovascular clinical events in high-risk patients.

Methods: We analyzed the effects of n-3 PUFA and of B vitamins on both coronary revascularization and on hard coronary events risks in a subgroup of the SU.FOL.OM3 trial, a randomized, double-blind, placebo-controlled secondary prevention trial. Data were analyzed according to the intention-to-treat principle, with the use of Cox proportional-hazards models.

Results: After a mean follow-up of 4.2 ± 1.0 years among the 1,863 participants with coronary heart disease, 163 coronary revascularizations were performed, and 95 patients experienced a hard coronary event. Neither treatment with n-3 PUFA, nor treatment with B vitamins was associated with any significant effect on the occurrence of hard coronary events. Allocation to n-3 PUFA was not associated with any significant effect on coronary revascularization. However, treatment with B vitamins was associated with a statistically significant 52% increase in the risk of coronary revascularization (multivariate HR: 1.52; 95% CI: [1.11-2.10]; p=0.01).

Conclusions: Neither n-3 PUFA, nor B vitamins reduced the rates of hard coronary events and of coronary revascularization. Furthermore, B vitamins significantly increased the rate of coronary revascularization. Consistent with the findings of previous trials, our results do not support the routine use of dietary supplements containing n-3 PUFA and argue against using dietary supplements containing B-vitamins in coronary patients in secondary cardiovascular prevention.