Adult Stem Cells Show Promise for Heart Failure

MONDAY, April 21, 2003 (HealthDayNews) -- An early trial shows that using a patient's own stem cells to bolster a failing heart seems to be safe and effective, researchers say.

Injections of stem cells extracted from bone marrow improved the heart's pumping ability, reduced the pain called angina, and caused no ill effects, says a new report in the April 22 issue of Circulation: Journal of the American Heart Association.

But it was a small trial, involving only 21 patients with end-stage heart failure, and larger trials are needed before the technique can be considered for widespread use, says Dr. James T. Willerson, president of the University of Texas Health Science Center at Houston and lead author of the paper.

"We're planning a lot more work to confirm what we've shown," Willerson says. "And we are planning to use stem cells as a vector to carry genes to the heart."

An ultimate hope is that stem cell injections might reduce the need for heart transplants, he says.

Stem cells are at an early stage of development and can develop into a number of different adult cells. Willerson and his colleagues began investigating their use for heart failure eight years ago, and undertook the study after successful animal experiments.

The therapy starts with extraction of cells from the bone marrow, a procedure resembling a routine biopsy, says Dr. Emerson C. Perin, who worked with doctors at the Hospital Procardiaco in Rio de Janeiro, Brazil. He is director of new interventional cardiovascular technology at the Texas Heart Institute.

The 14 patients who got the injections were in the final stages of heart failure and close to death, with no effective treatment available.

After bone marrow was extracted, it was filtered to remove cells known to be not useless, leaving a mixture that included the stem cells, Perin says. Meanwhile, a computer-generated map of each patient's heart was prepared "to display what muscle tissue is alive or scarred and areas lacking blood flow," he explains.

The patients then received an average of 15 injections each, aimed at areas of the heart that needed the most help. After two months, those patients were found to have significantly less angina and were better able to pump blood than seven patients in a similar stage of heart failure who were given standard therapy. No serious problems were seen in the patients who got the stem cell injections.

That appearance of safety has opened the door to larger studies, Perin says. A study to include 30 patients in Houston "has moved beyond the planning stage," he says. Those patients will be followed for a full year.

There are two theories about why the stem cell injections work, Willerson says: Either they develop into heart muscle and blood vessel cells or they stimulate the development of such cells. He leans toward the first theory.

If the treatment works, it could easily be adopted by large medical centers, Willerson says. It uses familiar technology and "is not terribly expensive," he says.

And while results with adult stem cells look good, Willerson is not ruling out therapy with fetal stem cells, whose use has been severely limited by the federal government.

"Fetal stem cells have the best potential," he says. "It is not correct to say that adult stem cells might have a favorable impact, even though they are enough to start with."

More information

You can learn about heart failure and its current treatment from the American Heart Association. Read this primer on stem cells from the National Institutes of Health.