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Chelation Therapy for Heart Disease Helps Some but Not All (research trial results)


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(Want to keep your heart & brain healthy as you age? See my other research-based posts in the Healthy Diabetes Living group forum (http://www.rvillage.com/group/878/diabetes-healthy-living) & the Healthy RVers (http://www.rvillage.com/group/80/healthy-rvers ) group forum at www.RVillage.com)

 

Copyright 2015, by David Leonard, M.Ag.

Nutrition Educator (retired)

University of NH Cooperative Extension

 

Every year, 100’s of RVers undergo chelation infusion therapy (a course of 20 to 40 infusions) primarily for heart disease at centers in Mexico along the border. Anecdotal stories abound about chelation’s benefits, but major medical associations won’t endorse it. Now the results of the first scientifically-conducted chelation trial provide valid but preliminary evidence of benefit for some (but not all) patients. Below is a summary of the trial. It’s long, so I’ve provided the “bottom line” directly below, followed by the details.

 

The Bottom Line on Chelation

The TACT trial detailed below demonstrated that properly administered chelation infusion therapy is safe and may have significant benefits for some (but not all) heart-disease patients who have suffered a first heart attack.

At the end of an impressive 5 year follow-up period, one out of every 12 patients receiving chelation + vitamin infusions benefited by avoiding one of the study’s adverse endpoints (like a second heart attack) used to evaluate the therapy's effectiveness.

 

For diabetics, one out of every 6.5 patients benefited, and there was a 43% lower incidence of all-cause death compared to placebo (16% death rate for placebo vs. 10% for chelation).

Others may well have benefited in ways that the study wasn’t designed to measure like increased energy, reduced exercise induced angina.

 

Despite the impressive 5-year follow-up period, the TACT study authors conclude that their results, by themselves, aren’t sufficient to recommend the routine use of chelation therapy without further supporting evidence.

 

Anecdotal success stories can over-inflate chelation’s benefits for several reasons: 1): Successes are more likely to make news than failures and don’t convey the reality that only a minority of patients significantly benefit; 2) Since chelation treatment lasts so long, the patient may have improved over time w/o treatment; 3) Some testimonials may be exaggerated (or become so as passed from person to person) or may even be bogus.

 

History of Chelation Therapy

Intravenous chelation therapy using disodium EDTA along with other ingredients was initially used in the 1940’s as an effective treatment of lead toxicity and removal of other war contaminants in patients. However, some chelation patients with heart disease also noted an improvement in their symptoms, especially angina (chest pain), and chelation therapy began to be used for this purpose in the 1950’s, particularly for patients with a prior heart attack. It’s also used for peripheral artery disease (PAD).

 

Despite chelation therapy’s increasing popularity over the years, its benefits remained largely based on anecdotal information (personal experiences) and some case reports. There were 3 small studies (2 on walking distance achieved for patients with PAD and one on exercise-induced angina in heart-disease patients). No benefit was found in all 3 studies, but they had too few participants to accurately detect differences.

Over the years, major medical groups like the AMA have consistently stated that chelation therapy for cardiovascular disease is ineffective and possibly dangerous. (It is true that an overly rapid infusion rate of EDTA can cause low blood calcium and possibly death).

 

Due to the growing use of this controversial therapy, the National Institutes of Health eventually approved and funded a well-designed randomized controlled trial (RCT) called TACT or Trial to Assess Chelation Therapy which took place from 2003 to 2011. RCT trials are considered the “gold standard” of research, because participants are randomly assigned to different treatments which also include a placebo treatment.

 

The TACT Study’s Design

The study’s endpoints (the outcomes used to measure chelation’s benefits): The composite (combined) incidence of the following adverse events among the 4 treatment groups during the treatment phase of the study and up to 5 years of follow-up:

▪▪ Another heart attack

▪▪ A stroke

▪▪ Need for a bypass procedure

▪▪ Hospitalization for angina

▪▪ Death from any cause

Study participants: 1708 men and women aged 50 and older with normal kidney and liver function, no history of heart failure, but who had suffered a prior heart attack (occurrence varied from 1.6 to 9.2 years prior to study). Candidates using tobacco within 3 months of the trial start were disqualified. The typical participant was overweight (average BMI of 30.0 which is borderline “obese”), 31% had diabetes, 56% were former smokers, 83% had undergone prior bypass surgery, and 73% were on statin drugs.

 

Location: Participants received treatment at one of 81 sites in the U.S. and Canada.

 

Treatments: Participants were randomized to one of 4 “blinded” treatments (neither researchers nor participants knew who was receiving which treatment during the entire trial):

1. Active chelation + active high dose oral vitamins (since these are usually part of chelation therapy; 28 vitamins & minerals were given)

2. Active chelation + placebo (sham) oral vitamins/minerals

3. Placebo chelation + active high-dose oral vitamins/minerals

4. Placebo chelation + placebo oral vitamins/minerals

In addition, participants in all 4 groups were given low-dose vitamins and minerals (B6, B12, zinc, chromium, copper, and manganese to offset potential depletion by chelation therapy.

Treatment length & follow-up period: 30 weekly infusions plus an additional 10 that were 2 to 8 weeks apart. Infusions lasted 3 hours each. Participants were examined on enrollment and visited during each infusion. After the final infusion, they were phoned quarterly, attended an annual clinic visit, and were seen at 5 years or at the trial’s end whichever came first.

 

The Study’s Results

Treatment compliance: A total of 55,222 infusions were made; 65% of the participants completed all 40 infusions (considered remarkable, given the time burden), and 76% had at least 30. About 30% discontinued the infusions.

Adverse effects & safety: 4 unexpected severe adverse events occurred that were possibly or definitely due to the treatments: 2 in the chelation groups (1 death), and 2 in the placebo groups (1 death). Hypocalcemia (low blood calcium) occurred in 6.2% of chelation patients and 3.5% of placebo patients. Heart failure occurred in 7% of chelation patients and 8% of placebo patients.

 

Was chelation superior to placebo?

▪▪ During the 5 years of follow-up, 32.8% of the active chelation participants suffered an adverse endpoint event (death from any cause, another heart attack, a stroke, bypass surgery or hospitalization for angina) compared to 38.5% of the placebo participants. That equals an 18% reduction in risk compared to placebo which was determined to be statistically significant (not due to chance).

▪▪ Based on these figures, an analysis showed that, at 5 years after treatment, one out of every 18 patients who received active chelation had benefited by avoiding one or more of the composite endpoint’s adverse events. The need for new bypass surgery was the most common occurring endpoint event (45%).

However, when each endpoint was examined individually, there was no statistically significant benefit for chelation, except for reduced death risk in diabetics (see below)

▪▪ Chelation’s benefits were greatest when comparing the chelation/vitamin group with the double placebo group (sham chelation and sham vitamins): a 26% relative reduction in incidence of the composite endpoint compared to placebo treatment. In this case, an analysis showed that, at 5 years after treatment, one out of every 12 patients who received active chelation had benefited by avoiding one or more adverse events making up the composite endpoint.

▪▪ Chelation showed the strongest benefit for participants with diabetes: a 41% lower relative incidence of the composite endpoint (a 25% incidence in the treated group vs. a 38% incidence in the placebo group. Moreover, all-cause mortality incidence was 43% lower in diabetics receiving chelation vs. placebo. The death incidence for diabetic participants was 10% in the chelation groups vs. 16% for placebo. An analysis showed that, at 5 years after treatment, one out of every 6.5 diabetic patients who received active chelation had benefited by avoiding one or more of the composite adverse endpoints.

▪▪ Another subgroup of chelation patients who especially benefited were those who had suffered a heart attack involving the left anterior descending artery which has the worst prognosis. There was a 37% relative reduction in endpoint incidence compared with the placebo participants.

▪▪ Note that the TACT study didn’t measure less significant possible benefits such as a reduction in exercise-induced chest pain or increased energy level anecdotally reported by a meaningful number of chelation patients over the years.

 

What Might Account for Chelation’s Benefit?

Researchers say the most likely mechanism is the chelation infusions’ ability to reduce levels of toxic metals like lead, cadmium, antimony, cobalt and tungsten that cause cardiovascular damage through oxidative stress caused by generation of free radicals. These toxic heavy metals are associated with heart attack and stroke. Chelation may also possibly improve blood vessel function.

 

As for chelation’s especially strong cardiovascular benefit in diabetes patients, a likely mechanism is a reduction of AGE’s (advanced glycation end products) generated by the body and the high-temperature cooking of foods (especially those high in animal protein like meat and cheese) by frying, broiling, baking, and grilling. AGE’s are linked to diabetes, heart disease, inflammation, blood vessel and nerve damage, and accelerated aging. People with diabetes are extra sensitive to AGE’s and should do most of their cooking at low temps (steaming, microwaving, stewing, boiling, poaching).

 

Could Lifestyle Changes Yield Similar Results?

There’s reasonable research evidence that chelation’s benefits (except for toxic metal decontamination) could be achieved through long-term lifestyle changes such as improved diet, regular exercise, and low-temperature cooking methods to reduce AGE’s for diabetics. For example:

 

The 4 year Lyon Diet Heart Study randomized 600 heart-attack patients to a Mediterranean-style diet (see http://oldwayspt.org/resources/heritage-pyramids/mediterranean-pyramid/overview) or to the American Heart Association’s recommended diet. At 4 years, the Med diet group had a 50-75% lower incidence of cardiac events (fatal & non-fatal heart attack, sudden cardiac death, and stroke) compared to the AHA diet (Circulation 1999;99;779-85).

 

A combined analysis of 23 randomized trials with 11,085 heart-disease patients found that lifestyle modification programs reduced all-cause mortality by 25% and heart-related hospital admissions by 26% over an average follow-up period of 10.2 months; some of the changes were maintained at an average long-term follow-up period of 33.7 months (Eur J Prev Cardiol 2013;4:620-40)

 

So, it's obvious that chelation patients should also adopt improved lifestyle to magnify benefits and broaden since exercise asnd healthy eating also reduce risk of cancer and dementia.

 

References

Note: I thoroughly reviewed the full-text medical journal articles below, not just their much shorter summary abstracts.

Effect of Disodium EDTA chelation regimen on cardiovascular events in patients with previous myocardial infarction (heart attack): The TACT Randomized Trial, JAMA 2013 March 27;309(12):1241-1250. Free full text available online at http://www.ncbi.nlm.nih.gov/pubmed/23532240

 

Chelation Therapy After the Trial to Assess Chelation Therapy: Results of a Unique Trial, Current Opinion Cardiology 2014, 29:481-88. Free full text available online at http://www.ncbi.nlm.nih.gov/pubmed/25023079

 

The effect of an EDTA-based chelation regime on patients with diabetes mellitis and prior myocardial infarction (heart attack) in the Trial to Assess Chelation Therapy (TACT). Circ Cardiovasc Qual Outcomes, 2014, Jan;7(1):15-24. Free full text at:http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4111470

 

IMPORTANT DISCLAIMERS

  • Seek & consider the advice of your physician or cardiologist before undergoing chelation therapy.
  • The info presented in this post should not replace professional medical or dietary advice, diagnosis or treatment.
  • Always consult your registered dietitian or physician before making any significant dietary changes.
  • Don't ignore professional medical advice due to the info presented here.
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