Healthy new heart cells have been generated in animals with chronic ischemic heart disease that received stem cells derived from cardiac biopsies or “cardiospheres,” researchers report.
The research demonstrated a 30 percent increase in healthy heart muscle cells within a month after receiving cardiosphere-derived cells (or CDCs). The finding is contrary to conventional wisdom that has held 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, the researchers said. While other investigators have largely focused on regenerating muscle in scarred tissue, the group has shown 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,” said study co-author John M. Canty Jr., M.D., professor of medicine and chief of cardiovascular medicine at the University at Buffalo School of Medicine and Biomedical Sciences.
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 said.
“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,” said Gen Suzuki, M.D., 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.”
Canty said that 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 is in a preclinical phase but the researchers expect that clinical testing could take place within two to three years.
The research was presented November 15, 2011, at the Scientific Sessions of the American Heart Association in Orlando, Fla.
Contact: John M. Canty Jr., 716-829-2663, canty@buffalo.edu
