Chelation therapy doesn't seem to be an effective treatment for heart disease.

Chelation therapy has long been used as a treatment for mercury and lead poisoning. And in the past, some people received chelation therapy to treat heart disease and stroke. But it isn't a proven treatment for these conditions. Chelation therapy also can cause serious side effects when used as a heart disease treatment.

Chelation therapy involves weekly treatments of medicine called ethylenediaminetetraacetic acid, also known as EDTA. The medicine is given through a vein. Each treatment lasts from 30 minutes to up to a few hours.

The medicine finds and sticks to metals and minerals in the bloodstream. This action forms a substance that works its way through the body and leaves in the urine. Some early researchers thought that EDTA might stick to and remove calcium found in plaque buildups that clog arteries. That's why they thought chelation therapy could treat heart disease.

But recent research suggests otherwise. Here's what is known so far:

• The Trial to Assess Chelation Therapy, also known as TACT, didn't find enough evidence to support routine use of this treatment for heart disease. But it did find that chelation therapy offered some protection to people with diabetes who'd had a past heart attack. The treatment seemed to lower their risk of future heart or blood vessel conditions, such as stroke and heart attack.
• A second study, TACT2, focused on people with diabetes who'd had a past heart attack. In this trial, chelation therapy didn't show the same promise for those with diabetes as it had in the first trial. TACT2 found that the treatment did not lower the risk of future heart attack, stroke or some related conditions.
• Before the results of TACT2 came out, key expert groups said that more research into chelation therapy was needed. The American Heart Association and the American College of Cardiology said it wasn't clear whether chelation therapy was helpful as a treatment for heart disease.
• The U.S. Food and Drug Administration hasn't approved chelation therapy for use as a heart disease treatment.

Chelation therapy for heart disease has known risks and side effects. The most common side effect is a burning feeling at the vein site where the medicine is given. Other side effects include fever, headache, upset stomach and vomiting.

Rare but serious complications of chelation therapy for heart disease include:

• Low blood-calcium levels.
• Sudden drop in blood pressure.
• Heart failure.
• Kidney damage.
• Death.

If you're thinking about trying chelation therapy as a heart disease treatment, talk with your healthcare team. Be sure that you understand what the research shows and what the risks are.