30% more heart cells after stem cell therapy

U. BUFFALO (US) — Animals with heart disease generated healthy new heart cells after a stem cell infusion.

The therapy, which involves injecting stem cells derived from cardiac biopsies or “cardiospheres” into arteries, could potentially apply to patients suffering from heart dysfunction arising from insufficient blood flow.

In the recent study, animals who received the infusions showed a 30 percent increase in healthy heart muscle cells within a month. The finding is contrary to conventional wisdom that heart cells are terminally differentiated and, thus, unable to divide.

Ischemic heart disease from coronary artery narrowing and prior heart attacks is the most common cause of heart failure. While other investigators have largely focused on regenerating muscle in scarred tissue, new research shows that cardiac repair could be brought about by infusing the CDCs slowly into coronary arteries of the diseased as well as normal areas of the heart.

“Whereas most research has focused upon irreversible damage and scarring following a heart attack, we have shown that a single CDC infusion is capable of improving heart function in areas of the heart that are viable but not functioning normally,” explains study co-author John M. Canty Jr., professor of medicine and chief of cardiovascular medicine at the University at Buffalo.

Areas of myocardial dysfunction without fibrotic scarring are common in patients with heart failure from coronary artery disease and that they arise from remodeling in response to a heart attack, as well as adaptations that develop from periods of inadequate blood flow, sometimes called hibernating myocardium.

“The rationale for our approach is somewhat analogous to planting seeds in fertile soil versus trying to grow plants in sand,” Canty says.

“We have shown that cells derived from heart biopsies can be expanded outside of the body and slowly infused back into the coronary arteries of animals with chronic dysfunction from restricted blood flow or hibernating myocardium,” says Gen Suzuki, research assistant professor of medicine and lead author on the research.

“The new cardiac muscle cells are small and function more normally than diseased large, hypertrophied myocytes.”

Infusing stem cell formulations directly into coronary arteries also delivers the cells throughout the heart and is much simpler than injecting cells directly into heart muscle which requires equipment that is not widely available.

The research currently is in a preclinical phase but Canty expects that translation to determine effectiveness in patients could take place within two to three years or possibly sooner.

The research was funded by the Department of Veterans Affairs, the Empire State Stem Cell Board, the National Heart, Lung and Blood Institute of the National Institutes of Health, and the Albert and Elizabeth Rekate Fund. The team presented their findings Nov. 15 at the Scientific Sessions of the American Heart Association in Orlando, Fla.

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