DESCRIPTION (provided by applicant): The purpose of the Trial to Assess Chelation Therapy 2 (TACT2) is to perform a pragmatic and efficient replication of TACT1 in patients with diabetes and a prior heart attack. The results of this trial will determine whether disodium ethylene diamine tetraacetic acid (Na2EDTA) chelation therapy receives approval from the US Food and Drug Administration (FDA) and is subsequently accepted to reduce the risk of major adverse events from coronary artery disease (CAD) in patients with diabetes. TACT2, if positive, will also promote research into the mechanism(s) of benefits and provide novel insights into the pathobiology of CAD. The Trial to Assess Chelation Therapy (TACT1) was developed in response to a Request for Applications from NCCAM and the National Heart Lung and Blood Institute (NHLBI) to address the concern that chelation use was widespread but there were no reliable data on either safety or efficacy. Surprisingly to cardiologists, the chelation strategy, combination of up to 40 infusions with intravenous disodium EDTA plus oral multivitamins and multiminerals (OMVM) compared with intravenous and oral placebo, led to a significant reduction in the time to first recurrent cardiovascular event in patients with prior myocardial infarction (MI), age 50 or older, already treated with standard evidence based medical therapies (HR 0.74; 95% confidence intervals (CI) 0.57- 0.95; p=0.016. The 5-year number needed to treat (NNT) was 12. In the prespecified subgroup with diabetes (n=633), the results were dramatic: the chelation-based strategy reduced the composite primary clinical endpoint by 51% (HR 0.49, 95%CI (0.33 0.75); p<0.001, 5-year NNT 5.5) and reduced total mortality by 43% (p=0.011, 5-year NNT 12). As a result of these findings, and because of the public health impact of cardiovascular disease and of diabetes, we have been encouraged by the National Institutes of Health (NIH) and the FDA to confirm the results of TACT1. The three Specific Aims of TACT2 are: 1) To determine if the chelation-based strategy in patients with diabetes and prior MI improves event-free survival; 2) To determine if the chelation-based strategy in patients with diabetes and prior MI reduces mortality; 3) To perform a cost-effectiveness analysis of the TACT2 chelation strategy. TACT2 will enroll 1200 diabetic patients 50 years of age or older with a prior MI and a serum creatinine of 2.0 mg/dL or less. Patients will be randomly allocated (1:1) to receive either chelation + OMVM or double placebo and followed for clinical events until the end of the 5 year trial. The primary endpoint will be a composite of all-cause mortality, recurrent MI, stroke, coronary revascularization, and hospitalization for unstable angina. A Clinical Events Committee masked to treatment assignment will adjudicate events. Principal secondary endpoints will include: (1) all-cause mortality; (2) a composite of cardiovascular mortality, recurrent MI, or stroke; and (3) safety.

PUBLIC HEALTH RELEVANCE: The purpose of the Trial to Assess Chelation Therapy 2 (TACT2) is to perform a pragmatic and efficient replication of TACT1 in patients with diabetes and a prior heart attack. The results of TACT2 will determine whether disodium ethylene diamine tetraacetic acid (Na2EDTA) chelation therapy receives approval from the US Food and Drug Administration and is subsequently accepted to reduce the risk of major adverse events from coronary artery disease in patients with diabetes. (End of Abstract)