Chelation therapy - long a treatment for mercury and lead poisoning - isn't a proven treatment for heart disease, and it can be dangerous when used as a heart disease treatment. Even so, some doctors and alternative medicine practitioners have used chelation therapy to treat heart disease and stroke.The theory behind using chelation therapy for heart disease is that the medicine used in the treatment binds to the calcium that's in fatty deposits (plaques) in your arteries. Once the medicine binds to the calcium, the plaques are swept away as the medicine moves through your bloodstream.The safety and effectiveness of chelation therapy for heart disease can't be determined, even after the results of the largest study conducted to date, the Trial to Assess Chelation Therapy (TACT), sponsored by the National Institutes of Health.Neither the American Heart Association nor the American College of Cardiology recommends chelation therapy as a treatment for heart disease, and the Food and Drug Administration hasn't approved chelation therapy for use as a heart disease treatment.