Scientists in Israel have successfully grown heart muscle in the abdomen and then used it to patch and repair the hearts of rats after they had suffered heart attack. This is the first study to show it is possible to improve the health of a heart after it has been damaged through heart attack.

The experiment was conducted by lead author Dr Tal Dvir, of the Department of Biotechnology Engineering at Ben-Gurion University of the Negev in Beer-Sheva, Israel and colleagues, and appears in the 24 August online issue of the Proceedings of the National Academy of Sciences, PNAS.

The authors wrote that recent progress in bioengineering of cardiac patches has raised the possibility of regenerating heart muscle after it has been damaged through heart attack.

They seeded cardiac cells taken from newborn rats with a mixture of growth factors and grew them on a “scaffold” that could be easily transplanted. After 48 hours in this culture, there was enough of the new tissue to enable it to be grafted into the omentum in the abdomen, where over 7 days it grew bigger and also grew a network of blood vessels (“vascularized”).

The researchers then removed the patch from the abdomen and transplanted it into the hearts of rats that had suffered a heart attack (myocardial infarction, MI) a week earlier.

28 days after transplant, the cardiac patches showed signs of being integrated into the heart muscle of the hosts both structurally and electrically.

Dvir and colleagues concluded that:

“Thus, our study provides evidence that grafting prevascularized cardiac patch into infarct can improve cardiac function after MI.”

After a heart attack, the heart muscle is usually unrepairable and if the patient survives, it is likely that they will then go on to develop heart failure due to the damaged tissue.

The authors hope their success will open the door to developing simple and safe new treatments for repairing heart muscle.

But they also cautioned that because most patients who have heart attacks tend to be older, they are at higher risk from multiple surgery (this procedure would require two invasions: one to the abdomen and then the heart one), so this may not be a good option for them.

“Prevascularization of cardiac patch on the omentum improves its therapeutic outcome.”
Tal Dvir, Alon Kedem, Emil Ruvinov, Oren Levy, Inbar Freeman, Natalie Landa, Radka Holbova, Micha S. Feinberg, Shani Dror, Yoram Etzion, Jonathan Leor and Smadar Cohen.
PNAS Published online before print August 24, 2009.

Written by: Catharine Paddock, PhD