After the 10 year trial that most thought (and many hoped) would result in the debunking of IV Chelation therapy for cardiovascular disease, JAMA has published the initial results of The Trial to Assess Chelation Therapy (TACT). The publication is free to download here.
The primary end point was a composite of death from any cause, reinfarction, stroke, coronary revascularization, or hospitalization for angina. The composite of cardiovascular death, reinfarction, or stroke was a pre-specified secondary end point. TACT was a “2×2” factorial trial where patients received 40 weekly infusions of EDTA or placebo and a high dose vitamin and mineral supplement or placebo. Because of the unique challenges created by recruiting patients for the trial, the normal p=value for statistical significance of <0.05 was dropped to a p<0.036 (a more stringent level of statistical significance). The 5-year estimate of reaching the primary end point shows that those given the EDTA chelation had a 18% lower risk (Hazard Ratio 0.82) which met the stringent level of statistical significance (p=0.035). The expectant lukewarm conclusion by authors was that the therapy “modestly reduced the risk of adverse cardiovascular outcomes, many of which were revascularization procedures. These results provide evidence to guide further research but are not sufficient to support the routine use of chelation therapy for treatment of patients who have had an MI.”
It should be mentioned that in the sub-group analysis, they saw much greater benefits in patients with diabetes (risk reduction of 39%, p=0.002) or with previous anterior MI (risk reduction of 37%, p=0.003) when given EDTA.
Not only did JAMA publish this paper, they published an interesting editorial to accompany its publication. While the typical editorial discusses the implications of new data or some clinical perspective regarding the publication, this editorial basically apologized to the JAMA reader for even publishing the TACT trial at all. After all, they are concerned that if JAMA is publishing this (positive) trial of EDTA chelation therapy it might be misconstrued as an endorsement. They wanted to avoid the certain avalanche of comments from readers who were already convinced that EDTA chelation is merely snake-oil in a bag. You might imagine that the editorial would have been much different (and unapologetic) had the primary end-point only reached a p=0.037! Here is the editorial for your reading pleasure [Free Online].
Also: Unpublished Data from TACT presented in San Francisco at the American College of Cardiology meeting earlier in March shows an even stronger clinical and statistical benefit when comparing patients receiving both EDTA and vitamin/mineral therapy compared to those receiving only placebo. A news story can be found here.