Special patch improves heart function after heart attacks

Jul 17 2007

Researchers in the U.S. have developed a special patch which regenerates cardiac cells after a heart attack; when the patch is placed on the damaged area of the heart it improves heart function.

A new study by researchers at the Children's Hospital in Boston tested the patch successfully on rats and they believe it may lead to new methods of repairing damaged human hearts and avoid the need in some cases for a heart transplant.

Lead researcher Dr. Bernhard Kuhn, from the Department of Cardiology at the hospital says adult human hearts do not regenerate after a heart attack because the heart does not produce more cardiomyocytes (heart muscle cells) after it has been damaged.

Dr. Kuhn and his team created a special patch that contains a compound called periostin, which helps cardiomyocytes divide and multiply and found after a number of cycles there was an increase in cardiomyocytes and lost cardiomyocytes were replaced.

Periostin, a natural component of tissue surrounding cells, comes from the skin surrounding bone and is abundant during fetal heart development; it helps stimulate cells to divide.

When a heart attack takes place the cardiac cells die from lack of blood and oxygen and the resulting damage prevents the heart from working normally; lost or damaged cardiac tissue cannot regrow.

Kuhn's team experimented by making patches from a material called Gelfoam and soaked the patches with periostin and then placed the patches on the damaged heart muscle of rats in which they had induced a heart attack.

After a 12 week period the rats treated with the periostin patch experienced a 16 percent improvement in their heart's cardiac pumping ability, had less scarring of heart tissue, a reduction in the size of the damaged area of the heart, and more blood vessels feeding the area.

In contrast, rats that received a patch without periostin showed no change in their heart function.

The hearts of rats treated with periostin were also seen to have a 100-fold increase in the number of heart cells and an average of 6 million more heart cells, far outnumbering the amount of dying cells.

Dr. Kuhn says the advantage of the technique is that it does not require new cells, such as stem cells, to coax the growth of new heart cells with the added danger that stem cells might migrate to other parts of the body, with unknown consequences.

Dr. Kuhn says as the patch is not gene-based it is not gene therapy.

Kuhn suggests it may be possible that the technique could be used in people who have severe heart disease, and though it might not restore heart function back to normal, there could be significant improvement.

Some experts are impressed by the findings and say the work is important as the ability to enhance cardiac regeneration holds great promise as new treatment strategies for heart attack victims.

Dr. Kuhn worked with colleagues at Massachusetts General Hospital and the Mount Sinai School of Medicine in New York.

The findings appear in the July 15 online edition of Nature Medicine.