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Gervasio A. Lamas, MD, FACC Professor of Clinical Medicine

Randomized Comparison of High-Dose Oral Vitamins versus Placebo in the Trial to Assess Chelation Therapy (TACT). Gervasio A. Lamas, MD, FACC Professor of Clinical Medicine Columbia University Division of Cardiology Mount Sinai Medical Center Miami Beach, FL. For the TACT Investigators.

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Gervasio A. Lamas, MD, FACC Professor of Clinical Medicine

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  1. Randomized Comparison of High-Dose Oral Vitamins versus Placebo in the Trial to Assess Chelation Therapy (TACT) Gervasio A. Lamas, MD, FACC Professor of Clinical Medicine Columbia University Division of Cardiology Mount Sinai Medical Center Miami Beach, FL For the TACTInvestigators

  2. Study Organization Funding agencies: NHLBI and NCCAM Clinical Coordinating Center: Mount Sinai Medical Center, Miami Beach FL Data Coordinating Center and EQOL Coordinating Center: Duke Clinical Research Institute Clinical Events Committee: Brigham and Women’s Hospital Central Pharmacy: Universal Arts, Miami FL Vitamins: Douglas Labs, Pittsburgh PA

  3. Background • TACT tested whether EDTA chelation reduced a composite cardiovascular endpoint in post-MI patients. • Chelation practitioners use high doses of anti-oxidant vitamins and minerals in conjunction with intravenous chelation. • Uncontrolled use of oral vitamins and minerals therefore constituted a potential confounder.

  4. Design Rationale • To clarify the relative contributions of high- dose vitamins and IV chelation, TACT was designed as a 2 x 2 factorial trial, with patients randomized to 4 groups: • Active oral vitamins + active IV chelation • Placebo oral vitamins + active IV chelation • Active oral vitamins + placebo IV chelation • Placebo oral vitamins + placebo IV chelation

  5. TACT: High-Dose Oral Treatment 3 caplets twice a day for the duration of the study. Calcium Iodine Magnesium Zinc Selenium Copper Manganese Chromium Molybdenum Potassium Choline Boron Inositol PABA Vanadium Citrus Flavonoids Vitamin A Vitamin C Vitamin D3 Vitamin E Vitamin K Thiamin Niacin VitaminB6 Folate Vitamin B12 Biotin Panthothenic Acid Double-blind active or placebo high dose vitamins were shipped from a central pharmacy to sites. Lamas GA, Goertz C, Boineau R, et. al. Design of the Trial to Assess Chelation Therapy (TACT). Am Heart J. 2012 Jan;163(1):7-12. 

  6. Eligibility • Age 50 or older • MI > 6 weeks prior • Creatinine <2.0 mg/dL • No coronary or carotid revascularization within 6 months • No active heart failure or heart failure hospitalization within 6 months • No cigarette smoking within 3 months • Signed informed consent

  7. Primary Endpoint • Primary composite endpoint: time to first occurrence of either death, MI, stroke, coronary revascularization, or hospitalization for angina

  8. Statistical Plan • Designed to have 85% power to detect a 25% difference • Treatment comparisons as randomized (intent to treat) • Two-sided statistical testing • Log-rank test using time to first event • Prespecified analysis of factorial groups

  9. Baseline Characteristics1708 patients randomized

  10. TACT Primary Endpoint Resultsfor EDTA Chelation (presented at AHA 2012) EDTA: Placebo HR (95% CI)0.82 (0.69, 0.99) P = 0.035 Death, MI, stroke, coronary revascularization, hospitalization for angina

  11. TACT Vitamin Primary Endpoint Results Vitamins: Placebo HR (95% CI)0.89 (0.75, 1.07) P = 0.212 37% 34% Death, MI, stroke, coronary revascularization, hospitalization for angina Median follow-up 55 months

  12. Components of the Primary Endpoint

  13. Subgroup Results for Vitamin Analyses 0.25 0.5 1.0 2.0 4.0 High-Dose Vitamins Better Placebo Better

  14. TACT Primary Endpoint: Factorial Groups EDTA Chelation/High-dose Vitamins vs. Placebo/Placebo HR (95% CI): 0.74 (0.57, 0.95) P = 0.016 Δ=8.3%

  15. Adherence • 75.6% took study vitamins for at least 1 year. • The most common reason for discontinuation was patient refusal (75%) • Median duration of treatment: 33.4 months. • No difference in discontinuation rate in active vs placebo vitamins.

  16. Limitations Compliance with high-dose vitamin regimen was challenging, leading to some non-adherence. High consent withdrawal rate (17%). The therapeutic mechanisms by which high-dose vitamins and chelation might provide benefits are unclear.

  17. Summary • High dose oral vitamins reduced the composite outcome by 11%, which was not statistically significant. • When combined with EDTA chelation, the small vitamin benefit was additive, and the combined effect was statistically significant.

  18. Caveats The results of this study do not support the use of high-dose vitamin and mineral therapy as an adjunct to optimal evidence-based medical therapy in patients with prior myocardial infarction. These findings should stimulate further research, but are not, by themselves, sufficient to recommend the routine use of chelation therapy and high-dose vitamins in post-MI patients.

  19. Thank you

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