If you're NIH's alternative medicine center, you double down. More than double, actually: NIH's NCCIH* just announced they will spend another $37 million to study chelation as a treatment for heart disease. Or to be more specific, Mount Sinai of Florida and Duke University issued a press release this past week proudly announcing that they'd won a $37 million grant to launch TACT2, the second Trial to Assess Chelation Therapy. TACT2 will be a followup study from TACT, which ended in 2012 after largely failing, as I'll explain below.
Chelation is a harsh chemical treatment, using a chemical called disodium EDTA, that is sometimes used to treat lead poisoning, because it can help to remove heavy metals from the blood. Some people think that this can somehow remove plaques from arteries, a sort of Roto-Rooter for your circulation, which in turn might improve cardiovascular health. This turns out to be wrong.
(Chelation is also promoted, tragically, as a treatment for autism. Anti-vax doctors who think that mercury causes autism have been pushing this for years. In 2014, the FDA issued a warning for parents to beware of this dangerous and ineffective therapy.)
Let's briefly review what TACT was, and some of its problems. There are far too many to list here, but I'll refer readers to a lengthy article published in 2008 by Dr. Kimball Atwood and colleagues for details. That article, which called for a halt to TACT, explained that:
- a series of randomized trials in the 1990s found no evidence that chelation worked for coronary artery disease
- most of the early advocates of chelation (in the 1960s) were also outspoken advocates for Laetrile and other ineffective therapies
- at least 30 deaths have been report associated with EDTA, but the doctors pushing its continued usage deny that any deaths have occurred.
- the scientific literature has shown that the underlying "heavy metals" hypothesis is implausible
- the TACT study includes "nearly 100 co-investigators who, in our opinion, are unsuitable to care for human subjects or to report trial data ... several have been disciplined, for substandard practices, by state medical boards; several have been involved in insurance fraud; at least 3 are convicted felons."
- "The researchers failed to inform the subjects that one risk of the treatment was death." (from The Chicago Tribune.)
Atwood and colleagues called for a halt to the TACT study, saying it was "pointless, dangerous, unethical, and wasteful."
The TACT study was indeed halted in 2008 for these and other ethical concerns, but it was quietly resumed about a year later. Then in 2012, the final results were reported. Although the results were almost entirely negative, the lead investigator, Gervasio Lamas, claimed that there was a benefit for a sliver of patients: people with diabetes who had a prior heart attack. That's the group he plans to focus on in the new TACT2 trial.
As Forbes writer Matt Herper explained in 2012, most doctors were highly skeptical of these results. Cardiologist Steve Nissen of the Cleveland Clinic said "It would be tragic if the result of this was a widespread use of chelation." Science blogger (and cancer doctor) Orac provided a detailed analysis of the results at the time, explaining why the study essentially failed to prove any benefit for chelation. Most of the results were not statistically significant, and the best the study could claim was very marginal significance for a small benefit, a result that could easily be explained by bias, which was rampant in this study.
TACT2 is being run by the same doctor, Gervasio Lamas, who recruited questionable practitioners into the first trial. There's no reason to think the second trial will be run any better. The new trial will subject 1,200 diabetic heart attack survivors to chelation therapy in an effort to prove that chelation helps prevent a second heart attack. Not only is this extremely unlikely to provide any benefit, it also exposes the patients to serious risks that Lamas and his colleagues don't seem to acknowledge, and probably won't tell the patients about.
NIH should pull the plug on this enormous ($37 million) and dangerous trial before it begins. If potential patients are informed correctly that there is a serious risk of harm with virtually no chance of benefit, then hopefully they will simply refuse to enroll. That would be the best outcome for everyone.
*In case you're wondering what NCCIH is, it's the new acronym for the former National Center for Complementary and Alternative Medicine, NCCAM. Last year it was renamed. The new name is the National Center for Crackpot and Implausible Hypotheses, Or maybe it's the National Center for Complementary and Integrative Medicine, you decide.