B Vitamins After a Heart Attack: Will They Prevent the Next One?

Cardiovascular disease is a major public health concern in the United States, as it is thought to contribute to approximately 1 in every 2.9 deaths. The lowering of homocysteine levels in the blood has been suggested to curb the risk for both coronary heart disease and stroke. The vitamins folic acid and vitamin B12 are known to lower homocysteine levels and make them an attractive therapeutic option for preventing cardiovascular events. However, evidence for this in the literature is marginal. A new study published in the Journal of the American Medical Association assessed folic acid and vitamin B12 supplementation in preventing adverse cardiovascular events in survivors of previous heart attacks.

The study was conducted in the United Kingdom and followed 12,064 heart attack survivors between 1998 and 2008. Patients were randomized and received either folic acid with vitamin B12 or a placebo. The authors then monitored the patients for adverse cardiovascular outcomes: heart attack, stroke, or death from a related event. Patients were followed for a mean of 6.8 years for cardiovascular events or related death.

Interestingly, those patients who received folic acid and vitamin B12 did have a decrease in homocysteine levels of approximately 28% in comparison to the control group. However, the rates of cardiovascular events between the vitamin treated and the control group were almost identical. The vitamin treatment group had 25.5% of patients experience a cardiovascular event, which also occurred in 24.8% of the placebo group patients. There were no differences between the type of event experienced between the groups, i.e. heart attack vs. stroke. The number of deaths due to a cardiovascular event was also very similar between the groups, 9.6% for the vitamins and 9.3% for the placebo.

This study suggests that although folic acid and vitamin B12 are efficient in lowering homocysteine levels, which had previously been postulated to lower cardiovascular risk, no benefit was gained in preventing recurrent adverse cardiovascular events.

References:

Study of the Effectiveness of Additional Reductions in Cholesterol and Homocysteine (SEARCH) Collaborative Group, et, al. Effects of Homocysteine-Lowering With Folic Acid Plus Vitamin B12 vs Placebo on Mortality and Major Morbidity in Myocardial Infarction Survivors. JAMA. 2010 Jun 23;303(24):2486-94.

Cardiovascular Disease Statistics. http://www.americanheart.org/presenter.jhtml?identifier=4478. Accessed 6/28/2010.