Lamas GA, et al.
This is the most significant study ever conducted on EDTA chelation therapy. Funded by the NIH and published in the Journal of the American Medical Association — the most widely read medical journal in the world — the Trial to Assess Chelation Therapy (TACT) enrolled 1,708 patients across 134 hospitals in the US and Canada. All participants had previously suffered a heart attack. Half received 40 infusions of IV EDTA; the other half received a placebo infusion. The primary endpoint was a composite of death, heart attack, stroke, coronary revascularization, and hospitalization for angina.
Patients in the EDTA group had an 18% reduction in the composite primary endpoint compared to placebo; many of the events avoided were revascularization procedures. The authors were careful in their conclusion: the results "provide evidence to guide further research but are not sufficient to support the routine use of chelation therapy for treatment of patients who have had an MI."
Bottom line — TACT remains the largest randomized trial of EDTA chelation for cardiovascular disease, demonstrating an 18% reduction in the composite cardiovascular endpoint in post-MI patients overall, with stronger effects in the diabetic subgroup. The follow-up TACT2 trial (Study 008), designed specifically to confirm the diabetic finding, did not reproduce that benefit. The TACT/TACT2 picture is now mixed: real reductions in blood lead were achieved in both, but the cardiovascular outcomes were positive in TACT and neutral in TACT2.