Muscle cell injection helps heart repair itself

ORLANDO, Fla. – Patients who had muscle cells injected into their hearts during surgery showed new tissue growth in areas left dead and scarred by heart attacks, according to a study released Tuesday in Orlando.

The small group of 24 people, in operations dating back to 2001, suffered no complications from the injection of cells taken from the patients’ own thighs, said Dr. Nabil Dib, an Arizona heart specialist and lead investigator in the study.

More research is under way, with the eventual hope of developing a treatment to boost the heart’s self-healing abilities and provide new options for patients with severely weakened hearts.

“We learned in medical school that the scar tissue caused by heart attacks is permanent damage,” said Dib, who presented the research at a meeting of the American College of Cardiology. “But here (in the study), we see evidence of new life in the area where the cells were transplanted.”

Three patients have died since their operations, but Dib said none of the deaths were related to the cell injections. All of them received the treatments during bypass surgeries to create new pathways around blocked arteries in their hearts.

Two of the patients died from later strokes and one passed away because the newly created bypasses failed, Dib said.

In addition to seeing fresh tissue growth in the damaged areas, Dib said, the patients had significant improvement in the pumping abilities of their hearts. On average, the patients increased from 21 percent heart function before the procedure to 34 percent afterward. Dib said 60 percent is considered normal.

“Any improvement of more than 5 percent will make a difference in terms of survival,” said Dib, director of cardiovascular research at the Arizona Heart Institute in Phoenix.

The initial study was meant to check the safety of using the cells, which are taken from a sample of muscle tissue removed from the thigh weeks before surgery. These particular muscle cells – called adult stem cells – have the ability to regenerate themselves.