The objective of the present study is to establish the safety and efficacy of Prochymal® following first acute myocardial infarction.

The standard of care treatment for acute myocardial infarction (AMI) usually includes immediate perfusion, optimal pain relief, oxygen, aspirin or other anti-coagulants, Beta-Blockers, nitrates and Ace-inhibitors. However, because salvaging the viable myocardium is dependent on early reperfusion, only a minority of participants will reach the hospital within the time-window for myocardial rescue. Thus, even if the participant manages their tobacco use, hypertension, lipid levels, diabetes, weight and exercise, many participants will go on to develop Congestive Heart Failure (CHF). Though the medical management for CHF may improve symptoms and slow disease progression, such treatment cannot restore a functioning myocardium. A therapy that could improve the myocardial remodeling process and reduce the incidence or severity of CHF following acute MI would provide a significant benefit. The characteristics and biologic activity of Prochymal®, along with a good safety profile in human trials to date, suggest that Prochymal® may be a good candidate for addressing this unmet medical need.

Inclusion Criteria:

• Male or female between 21 and 85 years old, inclusive
• First heart attack within 7 days prior to randomization and drug infusion
• Baseline left ventricular ejection fraction (LVEF) 20-45%
• Hemodynamically stable within 24 hours prior to randomization
• Adequate pulmonary function

Exclusion Criteria:

• Previous medical history of heart attack, heart failure, significant valvular heart disease, aortic dissection
• Pacemaker or other device
• Pregnant, breast-feeding, or intends to become pregnant during the study
• Allergy to cow or pig derived products
• Evidence of active malignancy or prior history of active malignancy
• Major surgical procedure or major trauma within the past 14 days
• Autoimmune disease (e.g., Lupus, Multiple Sclerosis)
• Any medical condition, which in the opinion of the Investigator, renders participation unsuitable
• Undergone pharmacologic cardioversion or external defibrillation within 24 hours of randomization.
• Experienced cardiac arrest more than 36 hours after presentation to site or within 24 hours of randomization.