Partial restoration of myocardial function and perfusion by cell therapy following myocardial infarction.
OBJECTIVE
In animals, both skeletal myoblasts and stem cells partially restore myocardial function after MI. This review provides a critical analysis of the initial clinical trials of these two therapeutic strategies.


RESULTS
Direct injection of autologous skeletal myoblasts into the peri-infarct area has been performed at bypass surgery and by subendocardial injection in the catheterization laboratory. Both approaches appear to improve function significantly. Nonetheless, ventricular arrhythmias occur quite frequently in the first week after myoblast injection. In contrast, stem cells can be delivered to the injured myocardium by direct injection, by IV injection, or by bone marrow stimulation. The incidence of ventricular arrhythmia does not seem to increase. The magnitude of absolute improvement in cardiac ejection fraction, however, is only about 7%. The potential limitations of stem cell therapy are cell fusion, creating genetically abnormal cells, and the ability to deliver sufficient numbers of cells to have an important biologic effect.


CONCLUSIONS
Cell replacement therapy after MI has considerable promise for restoration of cardiac function. Nonetheless because important theoretical and practical questions remain unanswered, the methodology is not yet ready for widespread clinical application.
Bick-Forrester
Justin
J
Division of Cardiology, Cedars-Sinai Medical Center, University of California, Los Angeles, School of Medicine, Los Angeles, California 90048, USA.
Lee
Michael S
MS
Makkar
Raj R
RR
Forrester
James S
JS
D017690:Cell Transplantation / Q000379:methods; D064987:Cell- and Tissue-Based Therapy / Q000379:methods* / Q000592:standards; D006801:Humans; D007275:Injections, Intravenous; D032448:Myoblasts, Skeletal / Q000166:cytology / Q000637:transplantation; D009203:Myocardial Infarction / Q000628:therapy*; D033581:Stem Cell Transplantation / Q000379:methods; D016896:Treatment Outcome