Cell transplantation for cardiac repair.

Despite remarkable progress in contemporary cardiovascular therapy, treatment of heart failure still remains a therapeutic challenge. Pharmacological treatment using -blockers, angiotensin converting enzyme inhibitors, and angiotensin-II receptor blockers, as well as surgical revascularization together with left ventricular reshaping procedures, has improved the quality of life for heart failure patients. At present, cardiac transplantation is the only radical treatment for end-stage heart failure patients who remain refractory to maximum conventional therapy, but the use of this technique is limited largely by organ shortage. There have been improvements in ventricular assist devices, and cardiac resynchronization has emerged as a promising treatment for patients with wide QRS complexes. However, most of these therapeutic options fail to address the fundamental cause of the problem, that is, compromised blood perfusion to the myocardium due to severe coronary atherosclerosis along with irreversible myocardial dysfunction and cell loss. Due to an inadequate intrinsic repair mechanism, the heart enters into a vicious cycle of left ventricular remodeling, characterized by progressive fibrosis and cellular degeneration. Thus, various cellular and molecular approaches that address these issues are currently generating a great deal of interest. Of these, both therapeutic angiogenesis and stem cellbased therapy show encouraging results. Cell transplantation is based on the concept that stem cells with myogenic and/or angiogenic potential might compensate for cardiomyocyte loss and improve myocardial blood flow. Stem cells of various origins and different potentials have been investigated. Autologous skeletal myoblasts were the first to undergo clinical trials. Bone marrow derived stem cells have the potential to differentiate into bone, hematopoietic cells, myocardial, and endothelial cells. The heterogenous mononuclear fraction of the bone Cell Transplantation for Cardiac Repair