Researchers at the University of Arizona College of Medicine–Tucson’s Sarver Heart Center discovered that some artificial heart patients are capable of growing new heart muscle. This finding raises the prospect of developing novel treatments for heart failure and possibly even curing it in the future. The journal Circulation published the findings of the study, which was co-led by a physician-scientist.
Hesham Sadek, MD, PhD, director of the Sarver Heart Center compared the repair of skeletal muscles to that of heart muscles, saying that “We have nothing to reverse heart muscle loss” when a damaged heart muscle does not grow back.
Sadek oversaw a worldwide team of experts that worked together to look into the possibility of cardiac muscle regeneration. The Leducq Foundation Transatlantic Networks of Excellence Program provided funding for the project. Colleagues at the University of Utah Health and School of Medicine directed by Stavros Drakos, MD, PhD, a pioneer in left ventricular assist device-mediated recovery, donated tissue from artificial heart patients to start the experiment.
In order to determine whether these samples contained newly created cells, teams from Sweden and Germany were led by Jonas Frisen, MD, PhD, and Olaf Bergmann, MD, PhD, of the Karolinska Institute in Stockholm. They employed their novel technique of carbon dating human heart tissue. The rate at which muscle cells recovered in artificial heart patients was more than six times that of healthy hearts, the researchers discovered.
“It is incredibly exciting because it confirms that the human heart has the inherent ability to regenerate,” Sadek stated. “This is the greatest evidence we have, so far, that human heart muscle cells can actually regenerate.”
Sadek previously published a study in Science that demonstrated that although cardiac muscle cells divide aggressively throughout pregnancy, they cease dividing soon after delivery in order to focus all of their energy on pumping blood through the body continuously, without any interruptions.
He revealed signs of cell division in artificial heart patients in 2014, raising the possibility that the heart muscle cells were repairing. “Bypassing the heart, the pump forces blood into the aorta,” he explained. “In essence, the heart is at rest.” Sadek needed to create an experiment to find out if patients with artificial hearts were truly experiencing muscle regeneration, even if his earlier research suggested that this rest would be good for the heart muscle cells.
“Humans have never before demonstrated irrefutable proof of heart muscle regeneration,” he stated. “This study offered concrete proof.” Sadek, however, is trying to determine why only 25% of patients showed any response to muscle regeneration.
He added, “It is extremely evident that the ones who respond have the ability to rebuild heart muscle, but it is unclear why some patients respond and some don’t.” Sadek thinks that individuals will not need a mechanical heart as a therapy in the future, and he hopes that this work will help people regrow their heart muscles.
-Raja Aditya
