October 23, 2006
Bone marrow stem cells treat recent heart attack patients in clinical trial
BY holly korschum
Patients who recently have suffered an acute heart attack are being recruited for a new Emory University School of Medicine clinical study. The study will use stem cells generated within the bone marrow to grow new blood vessels to improve circulation around the heart and enhance its function.
Although many patients recover at least partially from heart attacks, about 70 percent suffer permanent damage because the artery blockage causing the attack keeps oxygen from reaching parts of the heart muscle. At this time there are no available treatments to restore the function of damaged heart muscle.
Although the heart muscle cannot repair itself, recent studies show that when muscles do not receive enough blood, the body makes growth factors that stimulate the bone marrow to release progenitor or stem cells that “home” to the muscle and develop into new blood vessels or help repair damaged ones.
In the Emory Phase I/II clinical study, physicians are harvesting a population of stem cells from patients’ bone marrow and using a cell separation technique to sort out an enriched population of cells containing a high number of progenitor cells. The cells will be re-infused into the patients through cardiac catheterization. The study will determine whether providing a concentrated quantity of these specialized cells can improve heart muscle function. The cell separation is performed by Amorcyte, a biotech company that funded the clinical trial.
The study will enroll patients who have had acute heart attacks within the previous four to five days. Study participants already will have received the standard of care for their condition, including cardiac catheterization, angioplasty and implantation of a stent in the blocked artery. Patients then will be randomized to receive the stem cell treatment or to be part of a control group receiving no additional treatment. The study also will test different doses of the stem cell therapy to determine which dose is most effective.
The clinical trial is directed by Emory cardiologist Arshed Quyyumi and Emory Winship Cancer Institute hematologist and oncologist Edmund Waller. The trial is taking place at three medical centers in the U.S., including Emory Crawford Long Hospital and Texas Heart Center at the University of Texas at Houston. Atlanta patients who received their initial heart attack treatment at other facilities may enroll in the study at Emory Crawford Long.
“By delivering progenitor cells locally to the area where they are most needed, we hope to make a much larger number of cells available to the area of heart muscle damage,” said Quyyumi. “Not only does the body have a problem producing enough of these cells to repair the damage on its own, it also may have a problem mobilizing and homing them to the area of blockage. Previous studies in Europe have shown that a mixed population of bone marrow cells given after a heart attack was associated with improvement in heart muscle function. By obtaining an enriched population of progenitor cells from the bone marrow, we hope to make this therapy more potent and specific.”
The study will enroll 40 men and women at the three participating centers. Twenty patients will be randomly selected to receive bone marrow cells and 20 will be in a control group that does not receive the cells. Patients in the study will be followed closely for the first year after cell infusion and then at regular intervals over a five-year period.
To find out more about the study and eligibility, call 404-783-5908.