In patients with diabetes and previous MI, high-dose multivitamins and minerals did not reduce CV events
The follow-up to the Trial to Assess Chelation Therapy did not find the cardiovascular (CV) benefits with a combination of vitamins and chelation that were seen in the initial study of patients who had a myocardial infarction (MI), an ACP Journal Club commentary noted.
The second Trial to Assess Chelation Therapy (TACT2) was conducted in 88 sites in the US and Canada and randomized 1,000 patients to 40 weekly infusions of edetate disodium (EDTA)-based chelation solution, six caplets a day of a 28-component oral multivitamin and multimineral, or matching placebos, in a 1:1:1:1 ratio. All participants were ages 50 years or older, had diabetes, and had had a myocardial infarction (MI) at least six weeks previously. At five years, there were no significant differences between groups on the primary outcome of major adverse cardiovascular events (MACE).
The study was published on March 3 by JAMA Internal Medicine. The following commentary by Maham Shahid, MD, and Gunjan Y. Gandhi, MD, MSc, was published in the ACP Journal Club section of Annals of Internal Medicine on July 1.
More than 50% of adults in the USA use a dietary supplement. Vitamins have several purported benefits. However, vitamins have not been shown to reduce mortality; slow cognitive decline; or prevent autoimmune disease, cancer, or cardiovascular disease in persons who consume a well-balanced diet. Analyzing the effects of multivitamins is not straightforward because patients who use dietary supplements tend to have a healthier lifestyle.
A cross-sectional study of patients with diabetes found that high-level vs. low-level exposure to multiple vitamins was associated with all-cause mortality in men, patients aged ≥60 years, and non-Hispanic White people. However, the study was limited by its design, sample size (n = 484), and potential attrition bias. EDTA-based chelation therapy has been shown to reduce calcified coronary artery plaque volume in a single group study. The TACT2 trial did not reproduce the findings of the earlier TACT trial, which found that EDTA-based chelation plus multivitamins reduced the risk for MACE (mostly revascularization procedures) in patients with diabetes. TACT2 did find a nonsignificant but nominally higher rate of a composite of stroke, myocardial infarction, or death from cardiovascular causes with oral multivitamins and multiminerals. This result is best described as indeterminate due to insufficient precision.
Despite these negative results, nonmedical marketing and consumer interest in multivitamins and EDTA may persist due to consumer perception influenced by anecdotal reports, a growing belief in alternative health practices and trends, and marketing strategies by companies to promote these products.