Washington: A small human trial has proved that stem cells injected into enlarged hearts could reduce both heart size and scar tissue and improve function to injured heart areas.
Researchers said that though the study was small and more research was needed, the approach might someday be a breakthrough.
Patients, who have enlarged hearts due to damage sustained from heart attacks, can suffer premature death, have major disability and experience frequent hospitalisations.
Options for treatment are limited to lifelong medications and major medical interventions, such as heart transplantation.
Using catheters, researchers at the University of Miami injected stem cells derived from the patient`s own bone marrow into the hearts of eight men (average age 57) with chronically enlarged, low-functioning hearts.
“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,” said senior author Joshua M. Hare.
The researchers found that the heart size decreased an average of 15 percent to 20 percent, which is about three times what is possible with current medical therapies.
They also found that scar tissue decreased by an average of 18.3 percent and there was dramatic improvement in the function, or contraction, of specific heart areas that were damaged.
‘This therapy improved even old cardiac injuries. Some of the patients had damage to their hearts from heart attacks as long as 11 years before treatment,” said Hare.
The researchers had used two different types of bone marrow stem cells in their study — mononuclear or mesenchymal stem cells.
The study, however, lacked the power to determine if one type of cell works better than the other.
All patients in the study benefited from the therapy and tolerated the injections with no serious adverse events.
Hare`s study assessed the effect of stem cell injections differently from other studies of post-heart attack stem cell treatment.
His team measured contractility, scar size and structural changes of the heart.
Hare also said their findings suggested that patients` quality of life could improve as the result of this therapy because the heart is a more normal size and is better functioning.
The results are published in Circulation Research.