Escolar E, Lamas GA, Mark DB, et al.
This paper analyzed a pre-specified subgroup of the TACT trial — patients with diabetes mellitus who had previously suffered a heart attack. Diabetes dramatically increases the risk of atherosclerosis and cardiovascular events, making this population particularly important. The subgroup analysis was published separately because the findings were substantially stronger than the overall TACT result.
Diabetic patients receiving EDTA chelation had a 40–59% reduction in cardiovascular events compared to placebo — a markedly stronger effect than seen in the non-diabetic population. The researchers proposed that EDTA's ability to chelate metal ions that catalyze damaging glycation end-products may explain the amplified benefit in this group.
Bottom line — In a pre-specified subgroup analysis of TACT, diabetic post-MI patients receiving EDTA chelation showed a 40-59% reduction in cardiovascular events compared to placebo — substantially larger than the overall TACT effect. This finding generated the hypothesis tested directly in TACT2 (Study 008), which did not confirm the benefit in a dedicated diabetic cohort. The diabetic subgroup remains the most-studied population for EDTA cardiovascular research, with mixed results across the two major trials.