University of Louisville researcher Roberto Bolli and Piero Anversa at Brigham and Women’s Hospital in Boston are leading research into the procedure.

Here’s how it works: surgeons remove a patient’s stem cells and some other heart tissue at the time of coronary artery bypass surgery at Jewish Hospital in Louisville. This material goes go to Anversa’s lab in Boston, where the stem cells are separated from other heart tissue cells and allowed to grow. About three to five months after the bypass surgery, doctors in Louisville give the patients a transfusion of their own stem cells, targeting the scarred region of the heart. The technique used is minimally invasive.

So far, 16 patients have received the stem cell infusion.

The initial results are very encouraging, Bolli, director of the Institute of Molecular Cardiology and chief of the Division of Cardiology at UofL told the annual meeting of American Heart Association yesterday in Chicago.

Heart function is improving in patients who have had the procedure, he said.

Bolli told the AHA that data on nine patients taken four months after they received the stem cell infusion showed that left ventricular function (a measure of heart function) had increased by an average of 9 percent.

With drug-coated stents implanted after a heart attack, we see an increase of between 4 and 5 percent, he said.

Three patients received infusions more than one year ago. Their hearts have maintained the increased function that resulted from the infusions.

Mike Jones of Jefferson County, Kentucky, was the first person to receive the stem cell infusion in the study.

I’m doing a whole lot better than I deserve, Jones said. While I haven’t gone out jogging, I am able to do a whole lot more with my grandkids. I can play ball with them now, whereas before I could only pass the ball three or four times before I had to stop. I can’t take them on in a real game on the court, but it is a lot more than I could do previously.

Bolli stressed to the AHA that the findings are preliminary and larger-scale studies must be undertaken before the therapy can be used widely.