Earlier this week, a new secondary analysis of results of the Trial to Assess Chelation Therapy (TACT) was published in the journal Circulation: Cardiovascular Quality & Outcomes and presented at the American Heart Association meeting. The analysis suggests that the EDTA-based chelation treatments produced a marked reduction in cardiovascular events and death in participants with diabetes. Furthermore, the results suggest that treatments had no benefit in those who did not have diabetes.
TACT’s initial report published in the Journal of the American Medical Association earlier this year showed a modest, but significant, reduction in a cardiovascular events in the EDTA-treated participants. But what was particularly surprising to me, personally, was that an initial subgroup analysis showed a greater effect of EDTA treatment among participants with a self-reported history of diabetes. When these data in the 633 participants with diabetes were examined further, they showed a 41 percent overall reduction in the risk of any cardiovascular event; a 40 percent reduction in risk of cardiovascular mortality, non-fatal stroke, or non-fatal myocardial infarction; a 52 percent reduction in recurrent heart attacks; and a 43 percent reduction in death from any cause. In contrast, there was no significant benefit of EDTA treatment in in the subgroup of 1075 participants who did not have diabetes.
To me, these findings are a reminder that we need to keep an open mind in research, as scientific investigation is rich with examples of unexpected outcomes. TACT was not designed specifically to discover how or why chelation might benefit people with diabetes. The sub-group analysis of this clinical trial, although pre-specified, cannot be considered to provide a definitive answer. But it does generate intriguing hypotheses. These effects are large and potentially clinically important. This analysis suggests strongly that more research is needed to examine possible benefits of chelation in people with diabetes and the potential mechanisms.
Note: Post was updated to correct the number of study participants with diabetes (633, not 663).