One year ago the results of the TACT trial were published in JAMA, sparking an enormous controversy over the propriety of publishing a trial suggesting that chelation therapy might be beneficial in people with cardiovascular disease. Chelation therapy has long been a staple of alternative medicine, but until the publication of TACT it had received no credit whatsoever in mainstream medicine. TACT was supported by the NIH as part of an initiaitve to test the scientific basis of alternative medical therapies.
The JAMA paper reported positive results for the prespecified subgroup of patients who had diabetes at the start of the trial. Now a new paper, presented at the American Heart Association Scientific Sessions and published online in Circulation: Cardiovascular Quality and Outcomes, focuses on this important subgroup, and provides even stronger evidence for a possible benefit for chelation in patients with diabetes. The authors speculate that ethylene diamine tetra-acetic acid (EDTA) chelation might have an effect on metal-catalyzed oxidation reactions in the development of advanced glycation end-products, which appear to play a central role in diabetic complications.
The primary endpoint of the main trial – the composite of death, MI, stroke, coronary revascularization, or hospitalization for angina – was significantly lowered from 30% in the placebo group to 26% in the chelation group (HR 0.82, 0.69-0.99, p=0.035).