Purpose of review: This review examines the knowledge that researchers have gained during the past year regarding some fundamental questions about stem cell therapy. These questions concern patient selection and safety, the optimal type of stem cells, the best route for their delivery, the fate of the transplanted cells, and the mechanism by which this therapy works.
Recent findings: So far, candidates for cardiac stem cell therapy have been limited to patients with acute myocardial infarction and chronic ischemic heart failure. Currently, bone marrow stem cells seem to be the most attractive cell type for these patients. The cells may be delivered by means of direct surgical injection, intracoronary infusion, retrograde venous infusion, and transendocardial injection. Stem cells may directly increase cardiac contractility or passively limit infarct expansion and remodeling. This therapy is generally well tolerated, but the potential for accelerated atherogenesis remains a concern. Eventually, cell therapy may be combined with gene therapy to treat ischemic myocardium.
Summary: Stem cell therapy for cardiac disease is a rapidly evolving field. Most of the evidence accumulated so far, including preclinical and clinical findings, confirms the potential of this novel therapy. However, most of the fundamental knowledge needed to guide the application of stem cell therapy in cardiac disease is still lacking.