Are Stem Cells the next Therapeutic Tool for Heart Repair?

Cardiovascular disease remains the leading cause of morbidity and mortality in the United States and Europe. In recent years, the understanding that regenerative processes exist at the level of the myocardium, has placed stem cell research at center stage in cardiology. A stem cell is a cell that has the ability to divide (self replicate) for indefinite periods often throughout the life of the organism. Myocardial regeneration with stem-cell transplantation is a possible treatment option to reverse the deleterious hemodynamic and neurohormonal effects that occur after myocardial infarction and can lead to congestive heart failure. Embryonic stem (ES) cells, bone marrow (BM) stem cells, myoblasts, fetal cardiomyocytes, endothelial progenitors, resident cardiac progenitor cells, and tissue-derived stem cells are potential sources of stem cells. They regenerate heart by differentiation in the endothelial and cardiac lineages, neovascularization as well as influence on the local environment by the release of paracrine factors. Early phase I clinical studies indicate that stem-cell transplantation is feasible and may have beneficial effects on ventricular remodeling after myocardial infarction. The ongoing rigorously- designed trials will contribute greatly to this emerging and exciting new therapeutic approach for diseases of the cardiovascular system.