Stem cell injections for cardiomyopathy reverse and improve heart damage
In a small human clinical trial, researchers were able to show stem cell injections can reverse heart damage and improve function in damaged areas of the heart that become scarred after suffering a heart attack. The injections reduced the size of the heart, to improve a condition known as cardiomyopathy, and reversed damage from old heart attack, using stem cells from patient's own bone marrow.
Old heart injuries healed with stem cell injections
The study that included eight men, average age 57, used two types of bone marrow stem cells to determine which worked best. In each case, improvements were seen in heart function. Some of the men had heart damage that occurred 11 years prior to treatment.
Joshua M. Hare, M.D., the study's senior author and professor of medicine and director of the Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, University of Miami in Miami, Florida said, "The injections first improved function in the damaged area of the heart and then led to a reduction in the size of the heart. This was associated with a reduction in scar size. The effects lasted for a year after the injections, which was the full duration of the study."
Measurable improvements in heart function
The researchers explain improvements in heart function were measured differently from past studies of stem cell treatment following heart attack. The team looked at how well the heart contracts to pump blood to vital organs, scar size from heart damaged and structural changes of the heart.
"Studies of bone marrow cell therapy for ischemic heart disease in animals have shown improved ejection fraction (the amount of blood the heart can pump). However, this measurement has not reliably translated to early phase studies in humans," Hare said. "Ejection fraction may not be the best way to measure the success of stem cell therapy in the human heart."
In the current study, the researchers found the therapy decreased the size of the heart 15 percent to 20 percent, surpassing the effect of medications given to treat cardiomyopathy.The injections reduced heart size three times that seen with standard medical therapy that might include pacemaker/defibrillator implants, beta blockers, calcium channel blockers, diuretics, medications to control dangerous heart rhythms and for some patients blood thinners.
The treatment reduced the size of scarring in the heart an average of 18.3 percent and the injections significantly improved heart contractility in damaged areas, improving ejection fraction that can become impaired from cardiomyopathy severely enough to require heart transplant.
Stem cell therapy could improve quality of life for heart patients
The study suggests stem cell therapy can improve quality of life for patients living with heart disease that generally leads to congestive heart failure. Decreased pumping ability of the heart causes fluid buildup in the lungs and requires medications that also pose a significant financial burden to patients, many of which have side effects that require frequent monitoring.
Dr. Hare says the clinical benefits of stem cell injections for treating enlarged hearts still have to be proven in larger trials, but the study supports the value of ongoing research. Patients who don't respond to medical therapy suffer disability and frequent hospitalizations.
In the small study, stem cell injections dramatically improved heart function for patients with cardiomyopathy and reversed damage caused by heart attack. Improvements in ejection fraction were sustained one year after the bone marrow stem cell injections that were delivered to the study participants using a catheter. The findings are published in Circulation Research: Journal of the American Heart Association.
"Intramyocardial Stem Cell Injection in Patients With Ischemic Cardiomyopathy"
Adam R. Williams, Barry Trachtenberg, Darcy L. Velazquez, Ian McNiece, Peter Altman, Didier Rouy, Adam M. Mendizabal, Pradip M. Pattany, Gustavo A. Lopera, Joel Fishman, Juan P. Zambrano, Alan W. Heldman Joshua M. Hare