Stem Cells May Repair Injured Heart Muscle

An animal study suggests that transplanting embryonic stem cells can help repair injured heart muscle and improve cardiac function following heart attacks and congestive heart failure (CHF). The study was conducted by researchers at Beth Israel Deaconess Medical Center (BIDMC, Boston, MA, USA).

CHF is caused by the destruction of cardiomyocytes during a heart attack, resulting in ventricular dysfunction. The study was designed to determine whether implanted embryonic stem cells could survive in injured heart muscle and improve function. One of the advantages in using embryonic stem cells over other cells is to reduce immunoreactivity. The researchers surgically induced a heart attack in two groups of rats, one treated with a culture of embryonic stem mouse cells and one with a sham culture. Injections of stem cells were made at three separate sites in the heart, one on the place the attack took place and two in the heart muscle bordering the area.

Six weeks later, the researchers found that heart attack damage was reduced in the animals implanted with the stem cells. This group also showed significant improvement in left ventricular function. Animals in the control group did not show any improvement. Calculations revealed that the number of marked cells had successfully replicated, with 7.3% growth in the number of enzymatically isolated single cardiomyocytes. The cells were also rod-shaped with clear striations that mimicked heart muscle cells.

"These data strongly suggest that cardiogenesis, or growth of new cardiomyocytes, occurred in the damaged heart muscle following embryonic stem cell transplantation,” said Dr. Yong Fu Xiao, department of cardiology at BIDMC.




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