Stem cells might help fix failing hearts

HOUSTON, April 21 (UPI) -- Adult stem cells improved the heart function of patients seriously ill with congestive heart failure, giving hope the cells one day could be used to restore damaged hearts, a study released Monday concludes.

In one of the most comprehensive examinations of its kind to date, researchers from the Texas Heart Institute injected adult stem cells directly into the hearts of 14 patients in Brazil who were suffering from a severe form of heart failure and had no other medical options available.

Although still considered experimental, adult stem cells have the potential to become various cell types in the body and thus repair damaged tissue.

"We found that there was an improvement in both blood flow and function and a very substantial improvement in their symptoms," Dr. James Willerson, THI's medical director and chief of cardiology and the study's principal investigator, told United Press International.

Some of the patients "were able to do things they were not able to do before," such as walking much longer distances without being tired or short of breath, Willerson said.

"The bottom line is ... I'm very encouraged and our team is very encouraged by these findings," he said. The researchers plan to continue the work in Brazil and at the institute, he said.

Dr. Noel Caplice, a cardiologist at the Mayo Clinic in Rochester, Minn., called the results "promising" and said they confirm two smaller studies conducted in Germany last year. Those studies found adult stem cells showed potential for treating heart attack patients.

Patients suffering from congestive heart failure "really don't have a lot of options, so showing benefit in this group is very useful," Caplice told UPI. The findings could be good news for hundreds of thousands of people in the United States who suffer from this condition -- in particular because more than half have no treatment options available, he said.

Heart failure occurs when the heart loses the ability to pump blood efficiently. It typically is caused by high blood pressure or blockage of the arteries. About 550,000 Americans are diagnosed with the condition every year and about 51,000 people die annually.

In the study, which due to its significance is being released early in the April 22 online version of the journal Circulation, the researchers treated the 14 patients with about 15 injections each of adult stem cells.

The specific stem cell type used is called a bone marrow mononuclear cell. As its name implies, it comes from the patients' bone marrow.

After obtaining the stem cells from each patients' marrow, researchers then used a catheter -- a long tube threaded through the patients' artery and positioned in the left ventricle of the heart -- to inject the cells directly into undamaged areas of the heart.

Two months after the procedures, the treated patients showed signs of improvement compared to seven patients who did not receive the stem cell injections. The hearts of the treated individuals were able to pump more blood, they scored better on treadmill tests, and they had indications of new blood vessel growth.

"Overall, there was an improvement in both blood flow and function of the heart," Willerson said.

One patient in the control group and one patient in the treatment group died, he said, explaining this probably was due to the weakened condition of their hearts. However, the procedure appeared safe and all treated patients were discharged from the hospital three days after they received the therapy.

Further studies are needed to confirm these findings before the stem cell therapy is put into widespread use, Willerson said.

"We have to have this confirmed in a much larger number of patients," he said. "If it works there, and one could confirm there's no harm at all, then we will broaden" the applications of the therapy.

"One always has to be cautious," Caplice noted, because frequently the promising results seen in small studies will turn out to be elusive in larger trials. But he added the findings of the current study are "exciting" and justify a larger trial in this group of patients.

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(Reported by Steve Mitchell, UPI Medical Correspondent, in Washington)