Bone marrow-derived cell transplantation therapy for myocardial infarction: lessons learned and future questions.

Over the last decade, many investigators have utilized bone marrow-derived cells for cell transplantation therapy in animal studies and in patients with acute myocardial infarction and chronic heart failure. In those experimental and clinical studies, various doses and types of bone marrow-derived cells have been transplanted to the injured myocardium using a variety of approaches, such as intracoronary infusion or catheter-based direct endomyocardial injection, and at different time points after successful coronary reperfusion. The reported treatment effects are variable, which may be related to differences in cell type and quantity of transplanted cells, timing and approach of cell transplantation and patient selection. In this review, we summarize and discuss the controversies and questions related to the clinical use of bone marrow-derived cells.