Why the NIH Study of Chelation Therapy
Should Have Been Stopped

Stephen Barrett, M.D.

In May 2008, Medscape General Medicine published a book-length report calling for immediate termination of the National Institutes of Health's Trial to Assess Chelation Therapy (TACT). The $30 million clinical trial, which began in 2003 and was scheduled for completion in 2009, was intended to test whether intravenous disodium EDTA is effective against coronary artery disease. The report concluded [1]:

Shortly after the Medscape article was published, the NIH removed the password protection from its TACT “Portal” Web site, which originally was available only to investigators and others associated with the trial. Kimball Atwood, M.D. lead author of the Medscape article, quickly examined the site and found further evidence of impropriety [2]. To ensure that the documents would continue to be available for criticism, I uploaded the Portal site to Chelation Watch [3].

Two TACT suppliers listed in the documents have had serious legal difficulties: PharmedGroup, which supplied vitamin and mineral supplements, and Accu-Care Services Pharmacy, which delivered the supplements and provided the intravenous solutions used for the chelation therapy.

In September 2008, the American College for Advancement in Medicine (ACAM), which had spearheaded development of the study, announced that the study had been suspended because the Office for Human Research Protections (OHRP) is investigating "allegations of impropriety." [6]. NIH made no public announcement, but an astute reporter learned that the OHRP had opened the investigation after concluding that a complaint by the Medscape article authors had merit. TACT's principal investigator, Gervasio Lamas, M.D., of the University of Miami Miller School of Medicine, told the reporter that doctors who had been disciplined by state boards or have criminal records had been asked to drop out [7].

Early in 2009, after the FDA issued a safety warning, both U.S. companies that marketed the disodium EDTA that chelationists use stopped distributing it, which means that disodium EDTA would no longer legally available in the United States [8]. Lamas told the reporter that the EDTA used in the TACT study came from a European source [7].

In May 2009, without publicity, OHRP issued a letter agreeing that the study subjects were not given adequate information about the experimental nature of the procedures, the reasonably foreseeable risks and discomforts of the research, or the FDA's withdrawal of approval for the chelating drug. The letter also contained three "additional questions and concerns" that were sent to the project's directors but not publicly disclosed. Instead of stopping the sudy, however, OHRP said that patient recruitment could resume [9].

Atwood called the OHRP letter agency's "a remarkably damning statement" but said that the TACT should be stopped, and should never have been approved in the first place because not enough work had been done to suggest that the treatment is safe or effective [10]. Arthur Caplan, Ph.D., bioethics chief at the University of Pennsylvania, agreed and added that that subjecting anyone to the risk of chelation was "incredibly unethical."

Unimpressive Results - As Expected

The results of the trial were announced at the annual meeding of the American Heart Association in November 2012. The study measured five endpoints (death, myocardial infarction, stroke, coronary revascularization, and hospitalization for angina). The authors reported that, when all of the endpoints were combined the patients who received chelation did slightly better overall than those who received a placebo. However, none of the outcomes reached statistical significance when measured alone. There was also a high dropout rate. Only 65% of patients completed all of the planned infustion and 30% dropped out. The authors concluded that the results "did not constitute evidence to recommend the clinical application of chelation therapy."

Kimball A. Atwood, M.D., lead author of the above-mentioned Medscape article, has noted that although proponents will tout the study as validation, it actually demonstrates that their claims of "improvement" or "marked improvenemt" in 80% to 90% of patients are bogus [11]. It remains to be seen whether the study result will deter state boards from disciplining doctors who chelate patients for heart disease.

References

  1. Atwood KA and others. Why the NIH Trial to Assess Chelation Therapy (TACT) should be abandoned. Medscape Journal of Medicine 10(5):115, 2008.
  2. Atwood KA. The TACT is at least as bad as we predicted. Science-Based Medicine Web site, May 30, 2008.
  3. TACT Portal Web site, downloaded May 29, 2008.
  4. Pharmacy owner indicted, arrested for defrauding Medicaid. USDOJ press release, May 9, 2008.
  5. Two Pharmed directors sentences to 108 months on wire fraud conspiracy and tax evasion scheme. USDOJ press release, Jan 9, 2009.
  6. ACAM supports NIH decision to suspend TACT trial. ACAM Newswire, Sept 3, 2008.
  7. Marchione M. Government probes chelation-heart disease study. Associated Press, Sept 25, 2008.
  8. Barrett S. FDA issues chelation therapy warning. Chelation Watch, Sept 26, 2008.
  9. Buchanan LR. . Letter to William M. Abraham, MD, Eugne Z. Oddone, MD, and Myron Rosenthal, PhD. May 27, 2009.
  10. Atwood KA. Human subjects as political pawns. Science-Based Medicine Blog, July 1, 2009.
  11. Atwood KA. The Trial to Assess Chelation Therapy: Equivocal as Predicted. Science-Based Medicine Blog, Nov 4, 2012.

This article was revised on November 16, 2012.

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