In chelation therapy, a biologically based practice, a drug is used to bind with and remove hypothesized excess or toxic amounts of a metal or mineral (eg, lead, copper, iron, calcium) from the bloodstream. In conventional medicine, chelation therapy is a widely accepted way to treat lead and other heavy metal poisoning (see table Guidelines for Chelation Therapy). (See also Overview of Integrative, Complementary, and Alternative Medicine.)
Chelation therapy with EDTA (ethylene diamine tetraacetic acid) has also been suggested as a way to remove calcium and thus treat atherosclerosis. However, despite > 50 yr of study, researchers have not identified any mechanism to explain how chelation therapy could treat atherosclerosis or prevent heart attacks or strokes.
In 2012, a large randomized, placebo-controlled trial of chelation (the Trial to Assess Chelation Therapy [TACT]) found a significant benefit for chelation over placebo for aggregated outcomes (26.5% vs 30% for placebo), but not for individual outcomes (eg, death, cardiovascular events, stroke, hospitalizations) (1). However, this study had methodological flaws and did not end the controversy over chelation therapy. A subsequent systematic review of 38 studies showed possible but unclear benefits of chelation in regard to secondary prevention of recurrent cardiac events (2).
Risks of chelation therapy include
1. Lamas GA, Goertz C, Boineau R, et al: Effect of disodium EDTA chelation regimen on cardiovascular events in patients with previous myocardial infarction: the TACT randomized trial. JAMA. 309(12):1241–50, 2013. doi: 10.1001/jama.2013.2107.
2. Ibad A, Khalid R, Thompson PD, et al: Chelation therapy in the treatment of cardiovascular diseases. J Clin Lipidol 10(1):58-62, 2016. doi: 10.1016/j.jacl.2015.09.005.