Scientists at the Stanford University School of Medicine and their colleagues from the University of California-San Diego have delivered a protein to hearts damaged by heart attacks that helps injured tissue regenerate.

The protein, Fst11, is delivered by a bioengineered protein patch.

“This finding opens the door to a completely revolutionary treatment,” said Pilar Ruiz-Lozano, Ph.D.

“There is currently no effective treatment to reverse the scarring in the heart after heart attacks.”

When a heart attack occurs, cardiac muscle cells die from a lack of oxygen, causing scar tissue to form.

About 750,000 Americans suffer a heart attack each year, and even though many survive the initial attack, the loss of heart muscle tissue can lead to heart failure and death.

“Consequently, most survivors face a long and progressive course of heart failure, with poor quality of life and very high medical costs,” Ruiz-Lozano said.

Although researchers have tried different methods of transplanting healthy muscle cells into damaged hearts, none have yielded consistent results.

Ruiz-Lozano and her colleagues found that Fstl1, a protein secreted by the epicardium, was the growth factor for cardiac muscle cells, also called cardiomyocytes, and was missing from damaged tissue following heart attacks.

They attempted to reintroduce the protein back into damaged heart tissue of mice and pigs by sewing a patch made of collagen and infused with Fst11 to the damaged tissue.

Within two to four weeks of receiving the patch, heart muscle cells began to reproduce and the animals progressively recovered heart function.

“Many were so sick prior to getting the patch that they would have been candidates for heart transplantation,” Ruiz-Lozano said.

The researchers hope that a similar procedure could eventually be used in humans who suffer severe heart damage due to heart attacks.

The research was published in Nature.