Stem cell therapy successfully heals a scarred and failing heart

By Dr. Ananya Mandal, MDMar 17 2011

A new study has shown that stem cells could heal scars caused by old heart attacks. In all eight patients who received the experimental treatment in an ongoing clinical trial this therapy worked. All of them had suffered heart attacks an average of 5 1/2 years prior; one of the patients had his heart attack 11 years earlier.

According to the American Heart Association (AHA), heart enlargement can result from a number of health complications, including heart attack, congestive heart failure, and a form of heart muscle inflammation known as cardiomyopathy. Heart valve disease and high blood pressure can also contribute to heart enlargement as a result of heart muscle thickening. Over 5 million Americans are burdened now with an enlarged heart due to prior heart attack, the AHA says.

Study leader Joshua Hare said, “These are chronic heart failure patients ... with really bad [heart attack damage] and big [heart attack] scars…We wanted to see if the cells would heal the scarred area and allow it to start working again.” This study from the University of Miami Miller School of Medicine showed that it did. The team enrolled eight men at an average age of 57 who had heart attacks four months to 11 years earlier. All had enlarged hearts, with areas of scar tissue from their heart attacks.

For the study they harvested bone marrow cells from four patients and adult stem cells from another four patients. Using a catheter, they then injected the cells into the walls of the patients' hearts. Results revealed that within three months, the scarred areas of the patients' hearts began to work again. About six months after treatment, and for a year later all eight hearts regained a more normal size. They shrank 15% to 20%, three times more than current treatments can achieve.

Hare said, “If these bone marrow-derived cells did not have the capacity for regeneration, you would not expect them to make a dead scar start to function again…That is really the big deal here. We took two types of cells, whether just plain old bone marrow or [adult stem] cells, injected them right into the scar, and we were amazed. Three months later, the area that was completely dead started to contract again.”

According to heart stem cell expert Arshed Quyyumi, professor of medicine and cardiology at Atlanta's Emory University, stem cells are being explored in the treatment of people with recent heart attack damage. But the “landmark area” of the Hare study is the use of stem cells to treat end-stage heart failure. He added, “The excitement here is that for these dangerously enlarged hearts, in spite of the [heart attack damage] being old, there is something that actually reverses the enlargement and their propensity to get worse.” Quyyumi, who was not involved in the Hare study, notes that much more work must be done to confirm the findings, to find out exactly which bone marrow cells can heal hearts, and to find out how many of these cells are needed.

The investigators of the Transendocardial Autologous Cells in Ischemic Heart Failure (TAC-HFT) study are now preparing a 120-patient Phase I/II trial of their technique for transendocardial injection of bone marrow-derived progenitor cells. Hare hopes that further studies will confirm his early results. If so, the treatment could be available to patients well before the end of the decade. “This is on the horizon for people who need it,” Hare said. The study appears in the March 17 online edition of the journal Circulation Research.

The team said the stem cell treatment was well-tolerated with no serious side effects. Hare estimated that the procedure and the cells would cost approximately $10,000 to $15, 000, “not including a hospital fee if one was needed.”

The study received funding from the U.S. National Institutes of Health, the University of Miami Interdisciplinary Stem Cell Institute and BioCardia, which makes a catheter used in the procedure.

“We don’t have very much that works right now,” said Dr. Murray A. Mittleman, director of the Cardiovascular Epidemiology Research Unit with the Beth Israel Deaconess Medical Center at Harvard Medical School in Boston. “So if this sort of novel treatment improves outcomes that would certainly be helpful. Especially if it helps patients avoid getting to the stage where they would need a heart transplant.”