By Nancy McVicar
February is Heart Month, reminding us that heart disease remains the number one killer of both women and men in this country, accounting for nearly one in three deaths – 2,150 each day, according to the most recent statistics from the American Heart Association.
But ground-breaking research at the University of Miami Miller School of Medicine has the potential to reduce those numbers dramatically. Researchers have injected hearts damaged by a heart attack as long as 30 years ago with millions of cells that can regenerate their pumping ability without surgery – a feat long thought to be impossible.
“We think this is absolutely one of the most important areas of research going on today,” says Dr. Joshua Hare, director of the university’s UHealth Interdisciplinary Stem Cell Institute.
Stem cells taken from adult bone marrow – either from the patient or a donor – are grown in the lab to create millions of replicas. Called mesenchymal cells, they have the capacity to repair scarred hearts by rebuilding muscle, restoring good blood flow throughout the body, Hare says.
“In these patients scar tissue has damaged the heart in a permanent way leading to dysfunction in the heart and changing the shape of the heart,” he says. Such scarring weakens the heart’s pumping ability and is the most common cause of debilitating congestive heart failure.
In one early study, patients undergoing coronary bypass surgery had their own cells removed and grown in the lab weeks before the procedure, then injected into their hearts during the open heart surgery. In the most recent study, however, 30 patients got the cell injections through a catheter threaded up from the groin area into the heart.
Millions of the cells were injected at 10 different sites in the weakened or damaged part of the heart. Half got their own cells and half got donor cells. Results were published and reported in November at the annual American Heart Association conference in Los Angeles.
“In many cases we observed clinically significant improvement, even in patients who had heart attacks several decades ago,” Hare says. “Both [donor cells and the patient’s own cells] reduced the amount of scarring substantially.”
Dr. Alan Heldman, professor of medicine and a co-author of the study, who performed the cell injections, said because growing the patient’s own cells for use takes six to eight weeks, being able to use banked donor cells opens up a new door in potential therapy.
Hare says the researchers have applied to the National Institutes of Health to do a larger study. And more studies using different combinations of repair cells are on the horizon.
“What’s really exciting is a new trial funded by the NIH that will mix two types of cells, [cardiac stem cells and mesenchymal cells] and our belief is they will be better than one type alone,” he says.
“Millions and millions of people have had heart attacks and the people with the worst problems end up with a heart transplant, but there are only 2,500 of those a year,” Hare says, “so this is just an astounding advance – if it proves out – almost as ground-breaking as the discovery of antibiotics.”