Safety and Efficacy of MiSaver (CB Cells) for Acute Myocardial Infarction, Phase II

Inclusion Criteria: 1. Age ≥ 45 years, BMI ≤ 32 2. Patients diagnosed with acute myocardial infarction by a cardiologist, within 36 hours to 7 days post-diagnosis, and able to complete cell infusion within this period. 3. Left ventricular ejection fraction (LVEF) ≤ 45%, hemodynamically stable patients who do not require vasopressor support within 24 hours. 4. Patients with a history of coronary artery disease, who have previously undergone percutaneous coronary intervention or coronary artery bypass graft surgery, may also be included upon evaluation by a cardiologist. 5. Patients deemed unsuitable for percutaneous coronary intervention or coronary artery bypass graft surgery by a cardiologist. 6. Must agree to sign the informed consent form. 7. Subjects must use effective contraception during the study observation period and for 6 months after its conclusion to ensure no pregnancy occurs during the study. (Primarily for women of childbearing potential). 8. Agree to and comply with the required outpatient visits and examinations during the study observation period. Exclusion Criteria: 1. Age \< 45 years, BMI \> 32. 2. Women who are planning to become pregnant, are pregnant, or are breastfeeding 3. Immunodeficiency diseases caused by infection , such as Human Immunodeficiency Virus (HIV). 4. Patients diagnosed as needing coronary artery bypass surgery or potentially requiring coronary revascularization surgery within the next 6 months. 5. Severe aortic or mitral valve stenosis. 6. Life-threatening arrhythmias. 7. Malignant tumors, including all categories and cancer conditions. 8. Hematologic disorders or other severe organ diseases with an expected survival of less than one year. 9. Chronic kidney disease (eGFR \< 30 mL/min/1.73m²) or patients undergoing dialysis. 10. Patients with autoimmune diseases or those who have already received immunotherapy. 11. Patients who have undergone tumor treatment or require immunosuppressive therapy within the last three years. 12. History of transfusion reactions. 13. Recipients of bone marrow or organ transplants. 14. Liver dysfunction (bilirubin \> 2.5 mg/dL or transaminases \> 5x the upper limit of normal). 15. Patients who have previously received growth factors, cytokines, gene therapy, or stem cell therapy. 16. Subjects participating in more than one clinical trial. 17. Inability to sign the consent form or comply with outpatient follow-up after infusion therapy. 18. Patients with a known allergy to this product or its excipients (e.g., dimethyl sulfoxide, cell preservation solution).