Chelation for heart disease is usually mentioned in the same breath as laetrile for cancer -- dubious therapies used by fringe doctors and desperate patients.
But some influential medical experts have decided it’s time to give chelation a fair shake. Under the auspices of the federal government, the researchers have organized a five-year, $30-million study to determine if chelation is a safe and effective treatment for coronary artery disease.
During chelation, a synthetic amino acid solution is pumped through the veins to remove various substances from the blood. The procedure has long been approved by the Food and Drug Administration to remove lead and other toxic heavy metals; the amino acid, given intravenously, binds to the lead, allowing it to be excreted from the body. But it is not approved for heart disease, and the mechanism of how it might work is unknown.
While the estimated 1,000 U.S. doctors who offer heart-disease chelation are thrilled with the new study, others are aghast that so much money is being spent on a controversial therapy.
Dr. Ronald Hoffman, outgoing president of the American College of Advancement in Medicine, said in a statement that his group “has long awaited a comprehensive and fair evaluation of a therapy which we feel has a major role to play along with diet, lifestyle and appropriate conventional medical care.” The group, based in Laguna Hills, is the largest alternative health care medical society in North America.
But the director of the National Council Against Health Fraud, a nonprofit group that targets fraudulent medical practices and operates the Quackwatch Web site, says the study is a “terrible mistake.”
“It seems to me that there is no known rationale for doing this,” said Dr. Stephen Barrett. “This is a very strange amount of money to put out when there is no good data suggesting that it needs to be done.”
The study’s organizers say there is simply not enough scientific data on using chelation to treat heart disease -- and therefore it can’t be dismissed out of hand. The trial is not being done with the goal of disproving the therapy, says Dr. Gervasio A. Lamas, the principal investigator and director of cardiovascular research and academic affairs at Mount Sinai Medical Center-Miami Heart Institute in Miami Beach. “I wouldn’t design a clinical trial if I knew what the answer was,” Lamas says.
The study, which has been funded by the National Center for Complementary and Alternative Medicine, was conceived by Lamas several years ago after a patient with heart disease asked if he should have chelation therapy. (Although no one keeps track of chelation therapy for heart disease, the government estimates that about 800,000 treatments are performed each year in the United States.)
“I said, ‘Of course not,’ ” says Lamas, who calls himself a conventional cardiologist. “But then I decided to look into it and I realized I didn’t have the scientific evidence to say that to him.”
Lamas and his colleagues say that previous studies on chelation, most of which conclude it doesn’t work, were too small to draw firm conclusions. For example, a Canadian study of 84 cardiac patients released two years ago found no benefit to chelation therapy.
“There have been some small studies, not very well controlled, that suggested it was not very good,” says Lamas. “But when you read them, it’s pretty clear it’s completely inconclusive.”
Chelation practitioners point to anecdotal evidence in maintaining that a thorough examination of the therapy is needed. Dr. Richard Casdorph, an internist in Long Beach and one of the study investigators, began offering chelation therapy about two decades ago after conducting his own small studies suggesting that it works. “I have seen many patients over 20 years with marvelous results,” he says. “I think any well-designed study will show a benefit.”
But Barrett, of the National Council Against Health Fraud, says that simply studying chelation confers a certain legitimacy to the therapy and that the study results will have no bearing on its popularity. “Experience has shown that studying quack methods doesn’t have any effect on whether they continue or not,” he says. “If the study turns out negative [that chelation doesn’t work], the chelation people will say it wasn’t properly conducted and they’ll go right on doing it unless the regulatory authorities shut them down.”
The study, consisting of 2,300 patients 50 and older who have had a heart attack, will involve top cardiologists around the U.S. as well as so-called alternative practitioners who have long been treating patients with chelation therapy. It will begin enrolling participants in summer.
Conducted at about 120 sites around the country, the study will assign patients to either a group receiving chelation or a group receiving an inactive solution. Patients will undergo 30 weekly infusions of the dummy solution or the synthetic amino acid ethylene diamine tetra-acetic acid -- the same substance used to remove lead from blood -- followed by 10 bimonthly infusions. The patients in both groups will also be randomly assigned to take high-dose vitamins and minerals or a low-dose regimen. That component was added to the study, Lamas said, because alternative practitioners almost always prescribe vitamin and mineral therapy in conjunction with chelation.
“If we just did chelation and the study was negative, then the chelation practitioners would say, ‘Of course, it’s negative. You didn’t give the vitamins and minerals,’ ” Lamas says.
All of the patients will also receive conventional care for their heart disease, such as prescription medication and advice on eating and exercise. During the five years of the study, researchers will track the patients’ incidence of heart attack, stroke, hospitalization for angina and death. Chelation therapy has occasionally been linked with serious side effects, such as kidney damage, low blood pressure and allergic reaction.
“It is important for heart disease patients to know whether we should add chelation therapy to the list of proven treatments for coronary artery disease,” says Dr. Claude Lenfant, director of the National Heart, Lung, and Blood Institute, a co-sponsor of the trial. “Scientific evidence is needed to resolve this issue. And only a large clinical trial can definitely answer the question of whether chelation treatment is truly safe and effective.”
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How chelation might work
Although chelation therapy can remove lead and other substances from the blood, it’s unclear how it might reduce the severity of heart disease.
Some researchers suggest the treatment might work in much the same way it does in lead removal. However, instead of attaching to lead molecules in the blood, enabling them to be excreted from the body, the substance would attach to calcium found in the plaque that blocks arteries. Others believe chelation may stimulate the release of a particular hormone, causing cholesterol levels to fall and plaque to diminish. A leading theory is that the high vitamin C content in the solution is beneficial, says Dr. Gervasio A. Lamas. Vitamin C is an antioxidant, meaning it can help neutralize free radical molecules that damage blood vessel walls. “That is a huge antioxidant load” in the ethylene diamine tetra-acetic acid (or EDTA) solution, he says. “So my hypothesis is that the vitamin C, or some other components of the EDTA, may provide sufficient antioxidant load such that the patients will see some benefit in terms of their vascular health.”