In a significant finding that may ultimately prolong the life of heart attack victims, a team of researchers at the Harvard Medical School’s Beth Israel Deaconess Hospital have found that implanting certain stem cells into areas of the heart damaged by heart attacks may stimulate blood vessel regrowth.

Using mice as test subjects, the eight-member team of researchers implanted early differentiated cells into the myocardium, a part of the heart that is often damaged in heart attacks. Mice were injected with stem cells that either contained or did not contain a gene known to produce a protein that promotes blood vessel growth.

The early differentiated cells were obtained from the embryos of the mice.

Six weeks after the injections, the researchers found that damaged tissue had significantly regenerated in both groups of mice. The regrowth was especially pronounced in the mice injected with cells containing the blood vessel growth factor gene.

This tissue regeneration, in turn, increased the heart’s ability to function healthily.

Yong Fu Xiao, the senior researcher on the team, said the study has far-reaching consequences for those suffering from myocardial infarction (MI), a heart condition common in heart attack victims characterized by an insufficient presence of blood vessels within the myocardium.

Left untreated, the condition can ultimately weaken the heart, with healthy myocardial tissue developing into scar tissue.

“Our findings may provide critical information for future clinical cell and gene therapy in MI and heart failure patients,” Xiao wrote in an e-mail. “The public health benefits of this therapeutic approach are potentially great, because millions of patients in the world die of MI and heart failure yearly.”

While the findings present reason for optimism, they will not immediately result in treatment.

“There’s still probably a long way to go to move to the clinical trial,” Xiao wrote.

The study was first released in May of this year.