Inclusion Criteria:

1. Myocardial infarction due to coronary artery atherosclerotic disease and evidenced by typical ischemic symptoms, serial ST-T or Q wave ECG changes, and serum troponin I rise to > 99th percentile of the upper reference limit within 12 weeks of enrollment with at least one of the following: symptoms of ischemia, ECG changes indicative of new ischemia (new ST-T changes or new left bundle branch block), development of pathological Q waves on the ECG, imaging evidence of new loss of viable myocardium, or new regional wall motion abnormalities.
2. Prescreening left ventricular ejection fraction of ≥ 0.25 and ≤ 0.40 as determined by clinically-indicated assessment of cardiac function (echo, gated blood pool scan, x-ray contrast ventriculography, CT and/or MRI) one day or more following successful reperfusion.
3. An area of regional dysfunction, i.e. hypokinetic, akinetic, or dyskinetic, as assessed by echocardiography, left ventriculography, or MRI.
4. History of angioplasty and stent placement, with resultant TIMI flow > 2, in the artery supplying the infarcted, dysfunctional territory and through which the CDCs will be infused.
5. Left ventricular ejection fraction of ≥ 0.25 and ≤ 0.45 and infarct size of ≥ 17% of left ventricular mass as determined by screening MRI.
6. No further revascularization clinically indicated at the time the patient is assessed for participation in the clinical trial. This will be determined by a cardiologist who is not an investigator in the clinical trial. No further revascularization may be indicated by no arteries with a significant stenosis, the location and extent of any stenosis may not be suitable for angioplasty, the distal vessels may not be suitable for placement of bypass grafts, and/or the patient declines angioplasty or bypass surgery.
7. Ability to provide informed consent and follow-up with protocol procedures.
8. Age > 18 years.

Exclusion Criteria:

1. Measurable anti-HLA antibody levels (PRA > 0%).
2. Diagnosed or suspected myocarditis.
3. History of cardiac tumor, or cardiac tumor demonstrated on baseline MRI.
4. Contraindications to MRI, including prior ICD placement, estimated glomerular filtration rate < 50 mL/min (or GFR <30 mL/min during a prior protocol-mandated MRI study), known reaction to gadolinium, claustrophobia, pacemaker, ear implant, and cochlear implant. History of possible presence of ferromagnetic material including programmable shunt, shrapnel, penile prosthesis, intra-uterine device, bullets, tattoos, artificial limb, blood vessel coil, and tissue expander may require special screening.
5. Non-cardiovascular disease with expected life expectancy of < 3 years.
6. Requirement for chronic immunosuppressive therapy.
7. Participation in an on-going protocol studying an experimental drug or device.
8. Diagnosis of right ventricular arrhythmogenic cardiomyopathy.
9. Patients with occlusion or > 50% stenosis of the infarct-related artery at screening or before administration of CDCs.
10. Current alcohol or drug abuse because of anticipated difficulty in complying with protocol-related procedures.
11. Pregnant or child-bearing potential without use of effective contraception. Men intending to "father" children are also excluded.
12. Human Immunodeficiency Virus infection.
13. Viral hepatitis.
14. Uncontrolled diabetes and/or hemoglobin A1C > 8.5%.
15. Abnormal liver function (SGPT > 3 times the upper reference range) and/or hematology (hematocrit < 25%, WBC < 3000, platelets < 100,000) studies without a reversible, identifiable cause.
16. Sustained ventricular tachycardia not associated with the index myocardial infarction (> 48 hours after the MI onset) or a new acute ischemic episode.
17. Non-sustained ventricular tachycardia > 10 seconds not associated with the index myocardial infarction (> 48 hours after the MI onset) or a new acute ischemic episode.
18. Ventricular fibrillation not associated with a new acute ischemic episode.
19. Symptomatic ventricular tachyarrhythmia complicating the index myocardial infarction.
20. New York Heart Association Class 4 congestive heart failure.
21. Canadian Cardiovascular Society Angina Class 3 or 4.
22. Inability to rule out cancer based on screening chest/abdominal/pelvic (body) CT scan.
23. Any prior transplant.
24. Known hypersensitivity to dimethyl sulfoxide (DMSO).