CHICAGO, Nov 17: Researchers on Sunday reported progress on ways to repair a damaged heart following an attack — one using skeletal muscle cells and the other bone marrow cells _ both taken from the patient.

“We have been able to regenerate dead heart muscle or scar tissue in the area of a heart attack without increasing risk of death,” said Nabil Dib of the Arizona Heart Institute in Phoenix.

“Our findings will allow us to move forward with testing if the procedure can improve the contractility of the heart,” he added.

His study was released at the annual scientific meeting of the American Heart Association. It was released along with one from the University of Leicester in the United Kingdom, which found that bone marrow cells injected directly into the heart strengthened heart muscle and significantly enhanced heart function.

“The benefit could be seen only six weeks after injection,” said Manuel Galinanes, who led the study. “Bone marrow not only can differentiate into heart cells but also smooth muscle cells, connective tissue cells and other types of cells to reconstitute the entire structure of a tissue.”

Repairing a damaged heart is an important goal because heart muscle cells can’t repair themselves and the damage is thus irreversible, eventually resulting in heart failure. The scar or dead tissue left from a heart attack decreases the ability of the heart to force blood through its chambers. In the Arizona study, researchers extracted immature muscle cells from the thighs of 16 patients. The cells were grown and multiplied in a laboratory for three to four weeks. In a surgical procedure, injections of 10 million cells each were made into damaged areas of the heart.

“We found that the transplanted myoblasts (immature cells) survived and thrived in patients,” Dib said. “Areas damaged by heart attack and cardiovascular disease showed evidence of repair and viability.”

The study was the first such human testing done in the United States. At a meeting of the heart group in 2000, French researchers reported the first such transplant experiment, involving a 72-year-old man.—Reuters