In recent studies, stem cells that come from the patient's own bone marrow have been injected into the heart area within days or weeks of a patient's heart attack. The results have been consistently impressive, and there have been no catastrophic complications.
Studies are now in progress to judge how well stem cells may be able to treat angina -- the chest pain that is caused by narrowed cardiac arteries.
Directions of Research
"... Cell therapy is in its early stages, and various questions remain," writes Stefanie Dimmeler, PhD, et al., in the journal Arteriosclerosis, Thrombosis and Vascular Biology. In a 2008 article examining the use of cell-based therapies to treat heart attacks, Dimmeler and co-authors note that work still needs to be done to identify the patients who will "... benefit most from cell therapy, the optimal cell type ..." to determine how the cells actually do their therapeutic work, and to learn more about potential side effects.
However, most studies show that stem cell therapy reduced the impact of a heart attack and improved the heart's ability to pump. A 2007 article in the International Journal of Cardiology, for example, reported on a study that divided 70 cardiac patients into two equal groups: One group received injected stem cells and the other group received a placebo (both received standard heart attack care, including clot-busting drugs and/or angiography or bypass procedures).
Six months later, the patients treated with stem cells had a significant improvement in left ventricular pumping, and in the control group, there was no improvement. Twenty-five patients experienced complications, but none died.
It should be noted, however, that stem cell therapy to improve heart function is still an experimental technique and not ready to be applied to the general patient population. The number of patients studied has been relatively small, with short follow-up periods, and researchers still need to determine the long-term safety of the therapy and how many patients can benefit.
Sources:
Dimmeler, Stefanie, Jana Burchfield, and Andreas M. Zeiher. "Cell-Based Therapy of Myocardial Infarction." Arteriosclerosis, Thrombosis and Vascular Biology 28(2008): 208. 6 Nov. 2008. <http://atvb.ahajournals.org/cgi/content/abstract/28/2/208>.
Losordo, Douglas W., Richard A. Schatz, Christopher J. White, James E. Udelson, Vimal Veereshwarayya, Michelle Durgin, Kian Keong Poh, Robert Weinstein, Marianne Kearney, Muqtada Chaudhry, Aaron Burg, Liz Eaton, Lindsay Heyd, Tina Thorne, Leon Shturman, Peter Hoffmeister, Ken Story, Victor Zak, Douglas Dowling, Jay H. Traverse, Rachel E. Olson, Janice Flanagan, Donata Sodano, Toshinori Murayama, Atsuhiko Kawamoto, Kengo Fukushima Kusano, Jill Wollins, Frederick Welt, Pinak Shah, Peter Soukas, Takayuki Asahara, and Timothy D. Henry. "Intramyocardial Transplantation of Autologous CD34+ Stem Cells for Intractable Angina." Circulation 115(2007): 3165-3172. 6 Nov. 2008. <http://circ.ahajournals.org/cgi/content/abstract/115/25/3165>.
Steinwender, Clemens, Robert Hofmann, Jurgen Kammler, Alexander Kypta, Robert Pichler, Wilma Maschek, Gerhard Schuster, Christian Gabriel, and Franz Leisch. "Effects of Peripheral Blood Stem Cell Mobilization With Granulocyte-Colony Stimulating Factor and Their Transcoronary Transplantation After Primary Stent Implantation for Acute Myocardial Infarction." American Heart Journal 151(2006): 1296. 6 Nov. 2008. <http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6W9H-4K662M7-18&_user=10&_coverDate=06%2F30%2F2006&_alid=826038001&_rdoc=1&_fmt=high&_orig=search&_cdi=6683&_docanchor=&view=c&_ct=1&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=4235b6e9e1f62b47173cb8bca446cce8>.
"Stem Cell Basics." nih.gov. 2006. National Institutes of Health. 6 Nov. 2008 <http://stemcells.nih.gov/info/basics/basics2.asp>.
Zhan-quan, Li, Zhang Ming, Jing Yuan-zhe, Zhang Wei-wei, Liu Ying, Cui Li-jie, Yuan Long, Liu Xian-zhi, Yu Xian, and Hu Tie-shi. "The Clinical Study of Autologous Peripheral Blood Stem Cell Transplantation by Intracoronary Infusion in Patients with Acute Myocardial Infarction (AMI)." International Journal of Cardiology 115(2007): 52-56. 6 Nov. 2008. <http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6T16-4KBDWB1-2&_user=10&_coverDate=01%2F31%2F2007&_alid=826042268&_rdoc=1&_fmt=high&_orig=search&_cdi=4882&_sort=d&_docanchor=&view=c&_ct=1&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=746fc9bd69005e697d20625f1755debe>.
