The heart's ability to pump blood improved after patients were injected with adult stem cells taken from their own hearts, according to a study led by Dr. Roberto Bolli of the University of Louisville. A stem cell treatment for patients with heart failure significantly improved their heart function in a small but promising new study. In heart failure, the heart loses its ability to efficiently pump blood. It is most often caused by a heart attack, which destroys some of the muscle tissue essential to a normal heartbeat.

In this new study, patients were injected with adult stem cells taken from their own hearts. These are a special kind of undifferentiated cell found throughout the body that helps to maintain and repair the tissue in which they are found. Doctors use a measure called 'ejection fraction' to describe the heart's ability to pump blood. Study author Dr. Roberto Bolli of the University of Louisville says people in the control group showed no significant improvement in that measure. But he called the improvement in the stem cell patients "striking."

"At four months, the pumping ability of the heart was markedly improved," he reports. "The ejection fraction increased by eight points at four months, and at one year it increased by 12 points. Now, this is a huge increase, much greater than what we even hoped for when we started our study."