EDTA chelation therapy involves repeated administrations of a synthetic amino acid to reduce atherosclerotic plaque and other mineral deposits throughout the cardiovascular system.

Participants will be randomly assigned to receive 40 infusions of either the standard chelation solution or placebo. The primary endpoint of this trial will be a composite of all cause mortality, myocardial infarction, stroke, hospitalization for angina and hospitalization for congestive heart failure.

The results of TACT will provide either a significant positive result or an informative null result upon which rational clinical decision-making and health policy can be based.

Inclusion Criteria for Participants:

• Heart attack at least 6 weeks prior to study start

Exclusion Criteria for Participants:

• Chelation therapy within 5 years prior to study start
• History of allergic reactions to EDTA or any of the therapy's components
• Coronary or carotid revascularization procedures within 6 months prior to study start or a scheduled revascularization
• Cigarette smoking within 3 months prior to study start
• Childbearing potential
• History of liver disease
• Diagnoses of additional medical conditions that could otherwise limit patient survival