Transplantation of progenitor cells and regeneration of damaged myocardium: more facts or doubts? Insights from experimental and clinical studies.

The development of postinfarction left ventricular dysfunction, particularly in patients with a large myocardial infarction, remains a major challenge. Recent experimental studies, showing that bone marrow cells may repair cardiac tissue, have offered renewed hopes for the prevention of this ominous occurrence. This optimism is further supported by encouraging results from some clinical trials in both acute myocardial infarction and in chronic cardiomyopathy, although the degree of benefits, the underlying mechanisms, and the cell types involved remain to be elucidated. This review summarizes the most relevant experimental experiences and all clinical studies supporting but also questioning the use of bone marrow cells in myocardial repair.