Trial to Assess Chelation Therapy 2 (TACT2) is a randomized, double blind controlled factorial clinical trial of edetate disodium-based chelation and high-dose oral vitamins and minerals to prevent recurrent cardiac events in diabetic patients with a prior myocardial infarction (MI).

The primary objective of TACT2, therefore, is to determine if the chelation-based strategy increases the time to the first occurrence of any of the components of the TACT2 primary endpoint: all-cause mortality, myocardial infarction, stroke, coronary revascularization, or hospitalization for unstable angina compared to the placebo chelation strategy.

TACT2 is a 2x2 factorial trial testing 40-weekly edetate disodium-based chelation infusions and twice daily high-dose oral multivitamins and multiminerals (OMVM) in a placebo-controlled design.

TACT2 is being carried out to replicate the findings of TACT1, which found a striking reduction of recurrent cardiovascular events in post-MI diabetic patients receiving edetate disodium-based chelation therapy.

Inclusion Criteria:

1. Age: ≥ 50 years

2. History of diabetes, defined as medical record evidence or patient report of currently using insulin or oral hypoglycemic agents, or with a history of fasting blood glucose measurement of 126 mg/dL or higher, or a history of HbA1c of 6.5% or higher.

3. History of myocardial infarction based on the Universal Definition of MI.

   1. When information about the MI hospitalization is available, all MI types except Type 2 qualify for study entry.
   2. When information about the MI hospitalization is not available, a wall motion abnormality on imaging or a perfusion defect on scan that corresponds to a coronary distribution, whether or not accompanied by pathological Q waves in the appropriate distribution, will qualify the patient for study entry. This criterion requires a call to the CCC for case review.

Exclusion Criteria:

1. Baseline serum creatinine >2.0 mg/dL.

2. HbA1C >11%.

3. Myocardial infarction within 6 weeks of randomization.

4. History of allergic reactions to EDTA or any other components of the chelation solution, including heparin. Site personnel are to call the CCC to discuss heparin allergy.

5. Coronary or peripheral arterial revascularization procedure performed within the last 6 months.

6. Planned revascularization procedure in the 6 months following enrollment.

7. Heart failure hospitalization within 6 months prior to enrollment or in clinical heart failure at the time of proposed enrollment (such as NYHA Class 3 dyspnea + rales >basilar, and additional signs of fluid overload). Such patients may be treated with diuretics and enrolled when stable.

8. Poor or no venous access in the upper extremities.

9. a. Prior intravenous chelation therapy consisting of > 1 infusion within 5 years; if only 1 infusion took place, patient cannot be enrolled for at least 12 months after said infusion.

   b. Oral chelation therapy with an approved oral chelating agent within 2 years.

10. Prior participation in TACT.

11. Baseline platelet count <100,000.

12. History of cigarette smoking within the last 3 months.

13. ALT or AST > 2.0 times the upper limit of normal.

14. Wilson's disease, hemochromatosis, or parathyroid disease.

15. Any medical condition including a current diagnosis of cancer (except non-melanoma skin cancer) that will limit patient survival over the duration of the trial.

16. Any factor that suggests that the potential participant will not be able to adhere to the protocol.

17. Women of child-bearing potential including those with plans for post-menopausal in vitro fertilization or other reproductive technology.

All adverse events were collected from randomization until 30 days after their final infusion, approximately 13 months All-Cause Mortality was assessed through study completion, up to 48 months

Primary analyses were restricted to a modified intention-to-treat. Treatment adherence was imperfect. 12% of participants were lost to follow-up or withdrew consent.