A randomized clinical trial found that high-dose oral multivitamins and multiminerals may not reduce major adverse cardiovascular events in patients with diabetes and a history of myocardial infarction.
In the TACT2 study, published in JAMA Internal Medicine, researchers enrolled 1,000 participants aged 50 years or older across 88 sites in the United States and Canada. Participants had diabetes and had experienced a myocardial infarction (MI) at least 6 weeks prior to enrollment. They were randomly assigned to receive either a daily regimen of 28 components of high-dose oral multivitamins and multiminerals (OMVM) (n = 500) or placebo (n = 500).
The study population had a median age of 67 years, and 73% were male. Data were collected between October 2016 and June 2023, with a median follow-up of 48 months.
The primary endpoint of the study—a composite of all-cause mortality, MI, stroke, coronary revascularization, or hospitalization for unstable angina—occurred in 35% (and n = 175) of the participants in both the OMVM and placebo groups.
A secondary composite outcome—time to first event of MI, stroke, or cardiovascular death—occurred in 21% of the participants in the OMVM group and 16% of those in the placebo group. However, the difference was not statistically significant.
TACT2 used a 2 × 2 factorial design, also testing OMVMs in combination with edetate disodium (EDTA)-based chelation therapy. The researchers found no statistically significant difference between the group receiving active OMVM and EDTA chelation and the placebo group.
Adherence was high, with 91.4% of the participants in the OMVM group taking at least one dose at the final infusion visit. Adverse events were similar across the groups, though numerically higher MI, stroke, and cardiovascular mortality were observed in the OMVM group.
These findings aligned with prior research indicating no cardiovascular benefit of multivitamin supplementation.
"The results of this randomized clinical trial demonstrated that, for participants with chronic coronary disease, diabetes, and a previous MI, the use of high-dose OMVMs alone or in conjunction with EDTA-based chelation did not reduce cardiovascular events," said lead study author Francisco Ujueta, MD, and colleagues from the Brigham and Women's Hospital Division of Cardiovascular Medicine.
The study was supported by the National Center for Complementary and Integrative Health; the National Heart, Lung, and Blood Institute; and other National Institutes of Health divisions.
Full disclosures are available in the published study.