UAB cardiologist Massoud Leesar, MD has joined a national research study to investigate the potential for a new stem cell treatment in patients who have suffered an acute heart attack. The study is being done to find out if putting specialized bone marrow stem cells into a damaged heart can preserve blood flow and heart muscle function after they are injected into the coronary artery that caused the attack.
Previous studies performed on animals and a small number of humans have shown that infusion of stem cells may preserve the performance of the heart after a heart attack. UAB will be one of 30 sites in the United States participating in Phase II of the controlled study.
The study, sponsored by Amorcyte, LLC, will evaluate the effectiveness and safety of infusing the stem cells into the affected artery. Because stem cells are immature cells, they have the potential to develop into new blood vessels and preserve cardiac muscle cells. By infusing certain stem cells into the damaged area of the heart, tissue can be preserved and heart function restored.
“Preliminary studies showed promising results that heart function improved with bone marrow injections,” Lessar says. “We are finding that the amount of bone marrow injected may make a difference. When small amounts of stem cells were injected, we saw some benefit. Larger amounts should result in significant improvement of heart function.”
Phase II of the study focuses on patients who have received a stent to open the blocked artery after a critical heart attack that affects a large area of heart muscle. Lessar, who is Co-Director of the UAB Heart and Vascular Center, says study participants will receive injections of 10 million stem cells from their harvested bone marrow. “The contention with the initial study was that minimal improvement in patients resulted from injection of too few stem cells. That’s why we are injecting 10 million in this study,” he says. “The more cells injected, the more the heart muscle will regenerate. We hope to see significant improvement of the heart muscle function.”
A typical patient who suffers this type of attack can lose 40 to 60 percent of his or her heart function, Leesar says. “That means the heart may be functioning at only around 30 percent. If we get the results we are hoping for from this study, we may improve that level of function to 50 percent. That’s much better than 30 percent and may prevent a number of heart transplants,” he says. “Because there is a shortage of organs for transplant, this treatment could prove to be a great breakthrough.”
Leesar says the critical period for administering this treatment is within 10 days following the heart attack. “Because you lose heart muscle after the attack, it is better to harvest the bone marrow within that time frame. The results from the repair may not be as successful if you wait longer,” he says.
If this study is successful, Lessar says the next step will be a trial that will study a larger number of patients. “We need a larger patient base to prove definitively that this treatment is more effective than standard treatment for these heart patients,” he adds. “What we have seen so far gives us hope for patients who have a significant decrease in heart function.”