Pittsburg: The University of Pittsburgh Medical Center (UPMC) is about to start clinical trials to evaluate whether bone marrow stem cells can treat congestive heart failure.

The procedure in which stem cells are injected directly into the heart muscle, will be performed on up to 12 patients who are awaiting heart transplants.

The trial is one of only a few cleared by the U.S. Food and Drug Administration (FDA) for heart disease. Since the patients will receive transplants it will be the first time that researchers will be able to examine the affects on a human heart.

Despite advances that have given rise to more effective medical and surgical therapies, including the use of heart assist devices, heart disease continues to exact an economic burden and be a major cause of death in the Westerm world.

UPMC plans to enroll five to 10 patients. To qualify, patients must have congestive heart failure and require implantation of a ventricular assist device (VAD) as a bridge to transplantation.

Unlike the other FDA-approved trials, surgeons will not deliver the cells through a catheter leading into the heart’s coronary arteries but will instead inject them directly into the diseased heart tissue during the VAD implant surgical procedure. With the patient under anesthesia, Dr. Patel’s team will harvest bone marrow from the patient’s hipbone, and the cells believed to have the greatest therapeutic benefit, CD34+ cells, will be isolated. About three hours later, once the VAD has been implanted and connected to the heart’s main pumping chamber, the ventricle, the cells, together with a small amount of the patient’s blood plasma, will be injected into about 25 to 30 sites of the diseased heart in a process taking no more than five minutes. Depending on their weight, each patient will receive between 25 and 45 million stem cells.

In order to help the researchers better understand what effects the stem cells have on the cellular structures that surround the injection sites, they also will give patients injections containing only plasma to a different area of the heart. That way, once the native heart is removed, pathologists will be able to compare the differences between tissue samples from both areas, as well as make comparisons to tissue samples removed during routine biopsies, which are done at the time of the VAD implantation.