Chelation therapy for atherosclerotic cardiovascular disease

Not enough evidence about the effects of chelation therapy to reduce blockages in the blood vessels of people with atherosclerotic cardiovascular (heart and circulation) disease. Atherosclerosis is caused by fatty deposits sticking to the inside of people's arteries and restricting blood flow. People with blocked arteries are more likely to have strokes and heart attacks, and can often only walk short distances before their legs begin to ache. Chelation therapy involves infusions into the bloodstream of substances believed to remove metals from the blood. This is promoted to people with atherosclerotic heart and circulation disease as a way of breaking down the blockages in their blood vessels. However, the review found there is not enough evidence from trials about the effects of this treatment.

Authors' conclusions: 

At present, there is insufficient evidence to decide on the effectiveness or ineffectiveness of chelation therapy in improving clinical outcomes of people with atherosclerotic cardiovascular disease. This decision must be preceded by conducting randomized controlled trials that would include endpoints that show the effects of chelation therapy on longevity and quality of life among people with atherosclerotic cardiovascular disease.

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Background: 

Chelation therapy is being promoted and practiced all over the world as a form of alternative medicine in the treatment of atherosclerotic cardiovascular disease. It has been recommended as a safe, relatively inexpensive and non-surgical method of restoring blood flow in atherosclerotic vessels. At present the benefit of chelation therapy remains controversial at best.

Objectives: 

To assess the effects of ethylene diamine tetraacetic acid (EDTA) chelation therapy on clinical outcomes among people with atherosclerotic cardiovascular disease.

Search strategy: 

The Cochrane Peripheral Vascular Diseases Group Trials Register was searched, (last searched May 2005), the Cochrane Controlled Trials Register, (The Cochrane Library Issue 2, 2005), MEDLINE and EMBASE for published articles and other relevant articles. Studies were also requested through correspondence with known Filipino practitioners of the procedure.

Selection criteria: 

Studies were included if they were randomized controlled trials of EDTA chelation therapy versus placebo or no treatment in participants with atherosclerotic cardiovascular disease. Main outcome measures considered included either total or cause-specific mortality, non-fatal cardiovascular events, direct or indirect measurement of disease severity, subjective measures of improvement or adverse events.

Data collection and analysis: 

Two authors (MVV, FT) extracted data and assessed trial quality independently. Unresolved issues were considered by a third author (ALD). Discrepancies were discussed until a consensus was reached. Authors were contacted for additional information.

Main results: 

A total of five studies were included in the review. Mortality, non-fatal events, and cerebrovascular events were not reported in any of the studies. Four of the studies, with a total recruitment rate of 250 participants, showed no significant difference in the following outcomes: direct or indirect measurement of disease severity and subjective measures of improvement. One of the studies, which included only 10 participants, was interrupted prematurely, because of an apparent treatment effect. However, relevant data were not available in the report and have been requested from the authors.