(CBS) Is a cure for heart failure on the horizon? In a finding some are calling a breakthrough, heart failure patients given stem cells taken from their own bodies showed dramatic and lasting improvement.
The researchers tested the experimental stem cell therapy in only 16 patients, according to a written statement released in conjunction with the research. But if the finding is confirmed in additional studies, "It could offer an entirely new option and a potential cure for patients who are now dying from heart failure," study author Dr. Roberto Bolli, director of cardiology at the University of Louisville in Kentucky, told ABC News.
"The improvement we have seen in patients is quite encouraging," another University of Louisville researcher told WebMD.
"Michael Jones, our first patient, could barely walk 30 feet [before treatment]," Dr. John H. Loughran said. "I saw him this morning. He says he plays basketball with his granddaughter, works on his farm, and gets on the treadmill for 30 minutes three times a week. It is stories like that that makes these results really encouraging."
For the study - published in on Monday in The Lancet and presented at an American Heart Association meeting in Orlando, Fla. - researchers harvested stem cells from the patients' hearts during bypass surgery at Jewish Hospital in Louisville.All of the patients had severe heart failure, as shown by measurements of how much blood the heart's main pumping chamber, the left ventricle, was able to "eject" with each contraction. The patients all had a left ventricle ejection fraction (LVEF) of 40 percent or lower. An ejection fraction of 50 percent or higher is considered normal.
The stem cells were purified and allowed to grow in number, and then reinfused into the regions of the patients' hearts that had been scarred by their heart attacks. Four months after the reinfusion, the LVEF of the patients who had gotten the stem cells rose from 30.3 percent to 38.5 percent. One year after reinfusion, eight of the patients showed even more dramatic improvement.
In addition to testing ejection fraction, the researchers did MRI scans of the patients' hearts - and found that the area of scarring had fallen significantly in those who had gotten the stem cell treatment. That finding seems to disprove the long-held belief that once scarring occurs, the heart tissue is forever dead.
"The results are striking," Bolli said in the statement. "While we do not yet know why the improvement occurs, we have no doubt now that ejection fraction increased and scarring decreased. If these results hold up in future studies, I believe this could be the biggest revolution in cardiovascular medicine in my lifetime."
But other experts expressed caution.
"This is positive, but the crucial next steps are to see whether this improvement is confirmed in the final completed trial, and to understand whether the cells are actually replacing damaged heart cells or are secreting molecules that are helping to heal the heart," Dr. Peter Weissberg, medical director of the British Heart Foundation, told the BBC.
Dr. Bolli said a follow-up study is in the works.
The study comes more than two years after a heart failure patient at Cedars Sinai Heart Institute in Los Angeles became the first in the world to have stem cells from his own body reinfused into his heart, as CBS News reported.