Stem cell therapy for cardiac disease: what can be learned from oncology.

Hematopoietic stem cells (HSCs) are the most well-characterized and studied stem cells. They have been used to treat various benign and malignant hematologic disorders. Most stem cell transplant recipients survive more than 5 years without any evidence of their original clinical disease. Early animal trials have demonstrated the ability to improve cardiac function by transfer of HSCs into the myocardium, and early human studies have demonstrated the feasibility and safety of this approach. Trials in patients after myocardial infarction and with chronic heart failure have seen limited and mixed success, probably because of the various cell types and methods used.