TACT: Trial to Assess Chelation Therapy   Eligibility     • Age ≥50 years (if female, post-menopausal) • Prior heart attack, more than 6 weeks ago • No prior chelation therapy within 5 years • No hospitalization for heart failure within previous 6 months • No cigarette smoking within previous 3 months   Participant Involvement     Interested participants will attend a screening visit to determine eligibility. The screening visit is about 90 minutes long. Eligible participants will be randomized to one of the four study arms. All participants will take pills that contain either high- or low-dose vitamin/minerals, in three pills taken twice daily. In addition, all participants will receive 40 intravenous (IV) infusions of either chelation or placebo. The first 30 infusions will be given weekly, and the last 10 infusions will be given every 2-8 weeks. It may take up to 28 months to complete all the required infusions. Each infusion visit could take up to five hours (3 hours for the infusion plus other time for the medical staff to check recent medical history).     After the 40 infusion visits have been completed, Berman Center research staff call participants every 3 months until the end of the study to find out how they are doing and whether they have had any heart problems since the last call. In addition, participants will be asked to return for a Berman Center clinic visit each year and at the end of the study. At each visit, participants are asked questions about their medical condition and undergo a simple physical exam.   How to apply     Contact the Berman Center Site Coordinator, Mary Perron, RN at 612-341-7921.