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Chelation therapy for heart disease

Sharon Masinelli Baeten, MCMS, PA-C

Ms. Baeten works in a cardiology practice in Anchorage, Alaska. The author has indicated no relationships to disclose related to the content of this article.

Heart disease is the leading cause of death in the United States,¹ and many patients are seeking new treatments. One such treatment—IV chelation therapy—has become increasingly popular. According to the National Institutes of Health (NIH), more than 800,000 visits for chelation were made in 1997 alone.¹ A cohort study found that nearly 8% of cardiac patients have tried chelation as an alternative therapy.² Americans are spending as much as $3 billion yearly out-of-pocket.³

Chelation therapy Chelation involves the use of agents such as ethylene diamine tetra-acetic acid (EDTA), which eliminates heavy metals and minerals in the bloodstream.¹EDTA forms soluble complexes with lead, iron, copper, and calcium, allowing them to be excreted safely.⁴ It is FDA approved for treating heavy metal toxicity and hemachromatosis.¹ EDTA is also used as a laboratory anticoagulant in blood collection tubes and bags.

Although side effects are reported to be rare, they include a burning sensation at the IV site, fever, hypotension, hypocalcemia, headache, nausea, vomiting, bone marrow depression, and renal failure.¹ Other effects may be anemia, anorexia, arthralgia, chills, gout, peripheral neuropathy, phlebitis, proteinuria, tremors, and zinc deficiency.⁵

Use for heart disease EDTA has been used since the 1955 publication of an article reporting a decrease in angina in patients receiving EDTA chelation for lead poisoning.⁶ A review of publications up to 1999 confirms 16 additional reports and uncontrolled case studies between 1956 and 1993; all support the theory of cardiovascular benefit.⁷ The amount and frequency of the IV chelation treatments varies. Recent trials have used a minimum of 30 three-hour treatments administered at a rate of one or two per week.⁸ Standard protocols also include high-dose vitamins and minerals to counteract the depletion of beneficial substances by the chelation agents.^1,9

Traditionally, chelating agents were thought to bind with and remove the calcium in atherosclerotic plaques.¹ Specialists now believe that EDTA improves endothelial function by an antioxidative effect.^1,3,4 The NIH states, “Reducing oxidative stress could reduce inflammation in the arteries and improve blood vessel function.”¹

Recently, controlled trials have been unable to support chelation as an effective treatment. The first double-blind, randomized, controlled trial reported results based on improvement in exercise time to ischemia.⁸ Since both the chelation and placebo groups showed improvements, the authors concluded that “there is no evidence to support a beneficial effect of chelation therapy in patients with ischemic heart disease, stable angina and a positive treadmill test for ischemia.”⁸

In general, there is currently not enough evidence to prove that EDTA chelation therapy is effective in CAD. Validation by a well-controlled randomized trial is required. Various organizations have released statements discouraging patients from using chelation because of this lack of evidence.¹⁰

There is also only modest evidence to support safety claims. Early in the history of chelation, several deaths were associated with the treatments.⁷ Recent controlled trials have reported no deaths directly related to the therapy and few adverse events. One patient had a transient rise in creatinine levels, but they returned to normal after EDTA was discontinued.⁸

The NIH is funding a large-scale, double-blind, randomized clinical trial to evaluate IV EDTA chelation therapy in CAD. This $30 million study, called TACT (Trial to Assess Chelation Therapy), will be performed at approximately 100 research sites across the country and will include 2,372 participants.¹

The bottom line When a patient asks about this treatment, PAs should offer them enough information to make an informed decision. The facts are simple: chelation is a popular alternative treatment for CAD, the treatment involves some risks, several small studies have been unable to prove that chelation is more effective than placebo, and a large trial is expected to better determine safety and efficacy within 5 or 6 years. Until the results of TACT are published, patients should be advised that chelation remains an unproven alternative treatment.

For information that can be photocopied and handed to patients, please see the Patient Information sheet.

REFERENCES

1.    National Institute of Health. Questions & answers: the NIH trial of EDTA chelation therapy for coronary artery disease. Available at: http://nccam.nih.gov/news/2002/chelation/q-and-a.htm. Accessed December 8, 2004.
2.    Quan H, Ghali WA, Verhoef MJ, et al. Use of chelation therapy after coronary angiography. Am J Med. 2001;111:686-691.
3.    Lamas GA, Ackermann A. Clinical evaluation of chelation therapy: is there any wheat amidst the chaff? Am Heart J. 2000;140:4-5.
4.    Frishman WH. Chelation therapy for coronary artery disease: panacea or quackery? Am J Med. 2001;111:729-730.
5.    Access Medicine. Calcium EDTA. Available at: http://www.accessmedicine.com. Accessed December 8, 2004.
6.    Ernst E. Chelation therapy for peripheral arterial occlusive disease. Circulation. 1997;96:1031-1033.
7.    Ernst E. Chelation therapy for coronary heart disease: an overview of all clinical investigations. Am Heart J. 2000;140:139-141.
8.    Knudtson ML, Wyse DG, Galbraith PD, et al. Chelation therapy for ischemic heart disease: a randomized controlled trial. JAMA. 2002;287:481-486.
9.    Shelton B. Homotoxicology and calcium EDTA chelation. Explore. 2002;11(6). Available at: http://www.explorepub.com/articles/shelton2_11_6.html. Accessed December 8, 2004.
10.    American Heart Association. Chelation therapy: AHA recommendation. Available at: http://www.americanheart.org/presenter.jhtml?identifier=4493. Accessed December 8, 2004.