Marrow, Muscle Grafts Revive Broken Hearts

Transplants bring healthy cells back to scarred pump

SUNDAY, Nov. 17, 2002 (HealthDayNews) -- Injecting bone marrow into the scarred pumps of heart attack patients can reverse the damage and make the contracting muscle run better, a new study has found.

The study by British researchers adds to mounting evidence that muscle-generating cells in bone marrow can rejuvenate hearts deadened by infarctions, or loss of blood to the tissue. Previously, scientists had considered that damage irreversible.

"It has been the belief in general that you are born with a fixed number of [heart muscle cells], and that when they die they die forever," says Dr. Manuel Galinañes, a heart surgeon at the University of Leicester and leader of the research effort. "This has been challenged."

Scientists have demonstrated in animals that heart muscle can recover from attacks, and the latest work brings those findings to people. Galinañes presented the results today at a meeting in Chicago of the American Heart Association.

The researchers injected bone marrow into the hearts of 12 men and two women undergoing non-emergency bypass procedures to open blood flow to constricted areas. Each injection contained 32 million cells, drawn from the patients themselves to avoid rejection problems, which went into a total of 34 scarry patches of heart muscle afflicted by infarction.

Using a measure called wall motion -- which reflects the ability of the heart to contract -- Galinañes's group found that exercise test scores improved significantly in as little as six weeks. They continued to improve over 10 weeks of observation.

However, the researchers found that the only areas with better muscle activity were those that received both injections and new blood flow from the bypass. "It makes a lot of sense," Galinañes says. "When you seed a garden but you don't water the garden, or you do the reverse, you have no consequences."

In an unrelated study, also presented today at the heart meeting, Arizona scientists found grafts of skeletal muscle from the arms and legs could also revive scarred heart tissue. As in the British work, the Arizona patients -- who were undergoing either bypass or getting an implant to help their failing heart -- received their own cells, obviating the possibility of an immune reaction against the graft.

The procedure, in which doctors transplanted anywhere from 10 million to 300 million cells, led to nearly an average improvement in pumping power of nearly 60 percent in 16 heart attack patients.

Dr. Nabil Dib, director of cardiovascular research at the Arizona Heart Institute and leader of the study, says it's not clear how much of that was due to the grafts and how much to the other operations. However, he says, "clearly those [transplanted] cells do not deteriorate the heart function."

Imaging tests performed earlier this week show that after six months of follow-up the new cells are alive and settled into the heart, he adds.

Dib's group also did not see signs that the grafts caused irregular heartbeats, a potential side effect. The next step will be to see if the procedure indeed boosts pumping capacity.

What To Do

For more on heart attacks, try the American Heart Association or the Heart Information Network.

SOURCES: Manuel Galinañes, M.D., professor, cardiac surgery, University of Leicester, England; Nabil Dib, M.D., director, cardiovascular research, Arizona Heart Institute, Phoenix; Nov. 17, 2002, presentations, American Heart Association scientific sessions meeting, Chicago
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