Chelation therapy for blocked heart arteries?

I am frequently asked by my patients, and sometimes by other physicians, if chelation therapy helps patients with blocked arteries in the heart. Several clinics in Metro Manila and other key cities in the country are offering it as an alternative to heart bypass surgery or angioplasty, another intervention used to clear the obstruction when the heart arteries are occluded such that the normal blood flow to the heart is impaired. The patient usually has chest pains or a feeling of tightness in the chest radiating to the neck or right shoulder.

The use of chelation therapy in patients with coronary artery disease (CAD) has been a raging controversy, and there’s no clear answer whether it really helps or not. And while a recently concluded 10-year study evaluating it showed modest benefits that do not seem to outweigh the risks and cost it entails, in a convincing manner, unlike the proven medicines and procedures.

Chelation is a form of treatment in which a drug is administered either intravenously or by mouth to bind molecules, such as metals or minerals, and hold them tightly so that they can be removed from the circulation and from the body. Chelation has been scientifically proven to be effective for toxic metal poisoning. Lead poisoning, which can cause irreversible damage on the brain and nervous system, is a strong indication for chelation therapy in order to bind and remove the excess lead from the body.

Popular form

Edta (ethylene diamine tetra-acetic acid) is a popular form of chelation therapy being administered by some physicians in the Philippines. The solution consists of a synthetic, or man-made, amino acid that is delivered through the veins and is supposed to reduce the clogging of obstructed arteries in the heart. It is not approved by the US FDA (Food and Drug Administration) nor our local FDA for this indication.

Various associations of heart specialists including our own Philippine Heart Association have issued statements advising the public that there is a lack of adequate scientific research to verify Edta chelation therapy’s safety and effectiveness for CAD.

In his commentary on the status of chelation therapy in heart diseases in the May issue of H&L magazine, Dr. Ramon Abarquez Jr., professor emeritus of the University of the Philippines College of Medicine, also questions the cost- and risk-benefit of chelation therapy. He points out that the cost of 40 sessions of chelation therapy (which is the usual recommendation) plus professional fees may not be worth whatever modest benefit one can expect from it based on the Tact (Trial to Assess Chelation Therapy) study.

In the TACT study, conducted from 2003 to 2010, researchers enrolled 1,708 adults, aged 50 years old and older, from 134 sites in the United States and Canada who had already suffered a heart attack at least six weeks prior to inclusion to the study.

The heart experts do not appear to be convinced that chelation therapy is ready for prime time in the treatment of blocked arteries of the heart. Director Gary H. Gibbons, MD, of the National Heart, Lung and Blood Institute in the United States stated: “Further research is needed to fully understand these results (from the TACT study) before this treatment can be applied to the routine clinical care of heart attack patients. We do not yet know whether this therapy can be applied to most people with heart disease, which patients may potentially benefit from it, or how it may work.”

Even the study’s chief investigator or researcher does not seem that convinced. In a published commentary, he was quoted as saying, “more research is needed before considering routine use of chelation therapy for all heart attack patients.” The researchers reported that the treatment did not improve survival of the patients, taken as a whole.

Watch out for side effects

Those administering chelation therapy should also watch out for side effects which include, though rarely, serious and potentially fatal heart failure, a sudden drop in blood pressure, permanent kidney damage and bone marrow depression.

“Reversible injury to the kidneys, although infrequent, has been reported, if chelation therapy is administered by an untrained health professional,” says Dr. Abarquez.

So the jury is still out if the treatment can help heart patients or not. And for medical practitioners who are into chelation therapy, Dr. Abarquez gives this advice, citing a cardinal medical maxim in the practice of medicine: “First, do no harm.”