Abstract 10476: Effect of High-dose Oral Multi-vitamins and Minerals in Patients Not Treated with Statins in the Trial to Assess Chelation Therapy

Introduction: Trials of conventional dose vitamin therapy have been largely negative for coronary prevention. TACT studied an ultra-high dose regimen of oral multivitamins and multiminerals (MVM) in post-MI patients. Patients off statins were a pre-specified subgroup. Methods: 1708 patients were randomized in a double-blind factorial trial, to EDTA-based chelation or placebo, and oral MVM or oral placebo. MVM consisted of a 28-component mixture (or placebo), taken as 3 caplets twice daily throughout the 5 year study participation. To our knowledge, the oral antioxidant doses are the highest tested in a clinical trial. The primary endpoint was total mortality, recurrent MI, stroke, coronary revascularization, or hospitalization for angina. The results of oral vitamins versus placebo were not significant [HR (95%CI) 0.89 (0.75,1.07), p=0.212]. However, the pre-specified subgroup of patients not taking statins demonstrated an interaction with MVM (p=0.012). Both unadjusted analyses and comparisons adjusted for baseline prognostic factors were performed. Results: There were 460 (27%) (MVM: 224, placebo: 236) TACT participants not taking statins at baseline. Common reasons were: patient refusal 32%, physician preference 28%, and other 23%. Median duration of MVM therapy was 31 months (IQR 13-59 months).76% of patients completed one full year on vitamins, while 48% completed all 5 years. MVM patients had a 38% reduction in the primary composite endpoint compared with placebo (HR = 0.62, 95% CI: 0.44-0.87, p=0.006, FIGURE). Adjusted analyses reduced the significance of the findings without materially changing the HR (HR = 0.67, 95% CI: 0.47, 0.96, p=0.03). In patients taking statins, there was no beneficial effect of MVM (p=0.774). Conclusion: The present analyses cannot exclude a beneficial effect of MVM treatment for post-MI patients not taking statins. This unexpected result deserves confirmatory testing since it could be quite useful in practice if correct.