Can the heart heal itself? This question has puzzled researchers for years, and recent findings from the University of Arizona may hold the key to answering it. A research team co-led by physician-scientist Hesham Sadek at the university's Sarver Heart Center discovered a remarkable ability of certain artificial heart patients to regenerate heart muscle, presenting new hope for treating and potentially curing heart failure.
Heart failure, as defined by the Centers for Disease Control and Prevention, impacts nearly 7 million adults across the United States, causing approximately 14% of deaths annually. Currently, there is no cure, and therapies typically focus on managing symptoms and slowing disease progression through medications. The standard treatment for advanced heart failure remains organ transplantation. For patients unable to receive one, left ventricular assist devices (LVADs), artificial hearts, help the heart pump blood more efficiently.
Sadek, director of the Sarver Heart Center and chief of the Division of Cardiology at the U of A College of Medicine – Tucson’s Department of Medicine, emphasizes the difference between skeletal and heart muscle regeneration: “Skeletal muscle has a significant ability to regenerate after injury. If you’re playing soccer and you tear a muscle, you need to rest it, and it heals. When heart muscle is injured, it doesn’t grow back. We have nothing to reverse heart muscle loss.”
This study was funded by the Leducq Foundation, which promotes global collaboration among researchers. The project utilized heart tissue from patients with artificial hearts, with contributions from the University of Utah under the guidance of Stavros Drakos, MD, PhD. Other contributions came from the Karolinska Institute’s Jonas Frisén, MD, PhD, and Olaf Bergmann, MD, PhD, who employed innovative carbon dating methodologies to trace the regeneration of heart cells over time.
The results were compelling: patients with artificial hearts exhibited muscle cell regeneration rates exceeding six times those of healthy hearts. Sadek shared, “This is the strongest evidence we have, so far, of human heart muscle cells actually regenerat[ing], which is exciting, because it solidifies the notion of intrinsic capacity of human hearts to regenerate.” This finding not only provides insight but also supports the hypothesis concerning the heart's diminished ability to regenerate due to its continuous operation since birth.
Further underscoring the importance of this research, Sadek pointed out the need to grasp why approximately 25% of patients with artificial hearts show signs of regeneration. He mentioned, “It’s not clear why some patients respond and some don’t, but it’s clear those who do have the ability to regenerate heart muscle.” The potential to identify and increase responders could be transformative, as Sadek believes it opens pathways to effectively manage or even cure heart failure.
Historically, Sadek's research has paved the way for these findings. A paper published by him in Science back in 2011 noted heart muscle cells are capable of dividing before birth but cease this process shortly after, prioritizing their role in circulating blood continuously. Discoveries made later hinted at cell division mechanisms active in patients with artificial hearts, raising questions about whether this mechanical support allowed cardiac muscles the opportunity to rest and heal.
“The pump pushes blood via the aorta, bypassing the heart,” Sadek stated. “The heart is effectively resting.” His earlier studies indicated such rest could rejuvenate heart cells, but the challenge was to determine whether regeneration could be verified empirically. Through this latest research, they provided “irrefutable evidence of heart muscle regeneration,” according to Sadek, who expressed his enthusiasm for these outcomes.
Next steps for Sadek and his collaborative team involve exploring the molecular pathways interconnected with cardiac muscle cell division. “The exciting part now is to determine how we can make everyone a responder,” he said, noting the broader goal of ensuring these regenerative opportunities apply uniformly to all patients with heart failures. “These devices are tried and true, and we’ve been using them for years.”
The work reported—including the study led by Sadek and colleagues—can reshape how heart disease and treatment paradigms are approached, highlighting the potential for heart muscle repair even among those previously thought untreatable.
With innovative approaches and increasing clarity surrounding the heart's regenerative abilities, the dream of curing heart failure could possibly transition from fantasy to established reality, paving the way for future advancements aimed at improving countless lives affected by this silent but deadly condition.
