Functional and Histological Analysis of Stem Cell and Amniotic Membrane Implantation After Acute Myocardial Infarction with Left Ventricular Dysfunction: Experimental Study.

Acute myocardial infarction (AMI) results from a lack of oxygen supply to the myocardium, leading to the loss of cardiomyocytes and their replacement with fibrotic scar tissue. This process is closely associated with the development of heart failure. Regenerative medicine has emerged as a promising strategy to enhance treatment outcomes in severe cases of heart failure. This study aimed to evaluate myocardial regeneration after AMI using a biomaterial composed of mononuclear stem cells and human amniotic membrane. A total of 120 Wistar rats were subjected to experimentally induced AMI. On the 7th day post-infarction, rats with an ejection fraction of <50% on echocardiography were randomized into four groups: (1) control; (2) stem cells; (3) amniotic membrane; and (4) amniotic membrane combined with stem cells. On the 30th day, the surviving animals underwent a second echocardiographic evaluation and were subsequently euthanized. The group treated with the combination of amniotic membrane and stem cells showed reduced systolic and diastolic ventricular volumes. Histological analysis revealed that these animals exhibited less fibrosis and a lower percentage of type I collagen. Based on the results of the study, it was concluded that the combination of human amniotic membrane and mononuclear stem cells decreased ventricular volumes and myocardial fibrosis, suggesting more favorable ventricular remodeling in this experimental model.