The Structural Basis of Functional Improvement in Post-Infarct Rat Hearts with Stem Cell Treatment

Myocardial infarction (MI) is one of the major causes of heart failure in the world. Due to the loss of viable myocardium and high myocardial wall stress after MI, the heart undergoes progressive remodeling that will eventually lead to heart failure. Recently, cellular transplantation using stem cells has been proposed as a treatment strategy for preserving the myocardium in infarct area and border zones, as well as for improving global and regional cardiac function. The therapeutic effect of various types of stem cells has been investigated and many studies reported improved myocardial function after the treatment. However, the mechanism for this improvement, particularly at ventricular structural level, is still poorly understood. In the present study, we combined in vivo functional assessment of ventricular function with ex vivo characterization of myocardial structure to investigate the long-term effects of stem cell therapy on the structural and functional remodeling in post-infarct rat hearts. The results show that the functional improvement with stem cell therapy is correlated to the structural alteration in myocardial fiber architecture.