Adult stem cells may mend broken hearts

WASHINGTON - Adult stem cells could help repair heart tissue damaged by heart attack, reveals a new study.

According to results from the Phase I study, stem cells from donor bone marrow appear to help heart attack patients recover better by growing new blood vessels to bring more oxygen to the heart.

The 53-patient, double-blind, placebo-controlled Phase I trial has given the strongest evidence thus far indicating that adult stem cells can actually differentiate, or turn into heart cells to repair damage.

Until now, it has been believed that only embryonic stem cells could differentiate into heart or other organ cells.

“The results point to a promising new treatment for heart attack patients that could reduce mortality and lessen the need for heart transplants,” said Dr. Gary Schaer.

In phase I of the study, a group of 53 patients who had heart attacks in the previous ten days received adult mesenchymal stem cells and were kept under close study for two years.

The mesenchymal stem cells (MSC) were harvested from the bone marrow of healthy adult donors. These cells have the potential to develop into mature heart cells and new blood vessels.

After the stem cells were extracted, drug manufacturer Osiris Therapeutics purified them into a formulation for intravenous delivery called Prochymal.

Patients were administered an infusion of either Prochymal or placebo as an injection into a vein in the arm or leg.

In the study, patients who received the adult stem cells were compared to similar patients who received inert placebo injections. Both were followed by MRI and echocardiogram.

After six months, patients who received the adult stem cells were four times as likely to have improved overall condition, were able to pump more blood with each heartbeat than untreated patients, had only one-quarter as many dangerous heart arrhythmias, and suffered no toxicity or other serious adverse side effects from the treatment.

“It is suspected that these stem cells may take part in the growth of new blood vessels to bring more oxygen to the heart and help reduce the scarring from a heart attack,” said Schaer.

Echocardiograms showed patients had improved heart function, particularly in those patients with large amounts of cardiac damage. Patients also have improvements in lung function.

According to Schaer, the study results are so promising is that these stem cells can be used without tissue typing and do not trigger an immune response, and are available for every patient.

A unique benefit of the stem cell product is that it is given to patients through a standard intravenous (IV) line which is simple and easy for the patient.

The study will be published in the December issue of the Journal of the American College of Cardiology. (ANI)