Groundbreaking research from the University of Sydney, the Baird Institute, and Royal Prince Alfred Hospital has found that the human heart is capable of regrowing some of its muscle cells after a heart attack.
This surprising discovery opens up exciting possibilities for new treatments that could help the heart heal itself and reduce long-term damage from heart attacks.
Until now, scientists believed that once heart muscle cells die during a heart attack, the damage is permanent. The dead areas become scar tissue, leaving the heart weaker and less able to pump blood to the rest of the body. However, this new study shows that while the heart does form scars after an attack, it also creates new muscle cells.
Dr. Robert Hume, the first author of the study and a researcher at the University of Sydney and the Baird Institute, explained the importance of the finding. He said, “We’ve always thought that heart muscle lost in a heart attack couldn’t be replaced. Our research shows the heart does try to regrow some of that muscle. This could be the start of something big.”
Although the amount of regrowth seen so far is not enough to fully heal the heart or prevent heart failure, the researchers believe that understanding how the process works could help them find ways to boost it. In the future, treatments might be able to help the heart make even more new cells and recover more effectively after damage.
This is the first time scientists have observed this cell regrowth in human hearts. In the past, similar changes were only seen in mice. The process behind it is called mitosis—where cells divide to make more cells—and while researchers knew it happened in animals, it had never been proven in people until now.
Heart disease is the number one cause of death worldwide. In Australia alone, it causes almost one in four deaths. Heart attacks are especially dangerous, often killing about a third of the muscle cells in the heart. Even with improved survival rates, many patients later develop heart failure.
The only permanent cure for heart failure is a transplant, but with over 144,000 people in Australia living with heart failure and only around 115 heart transplants done each year, new treatments are urgently needed.
One of the key breakthroughs of this study was how the research team collected heart tissue. They used a new method to take samples from living patients during heart bypass surgery at Royal Prince Alfred Hospital.
This was the first time in the world that living heart muscle tissue had been taken in this way. The samples came from both damaged and undamaged areas of the heart, giving scientists a rare and detailed look at what’s really happening inside.
The method was developed by Professors Paul Bannon and Sean Lal, who are part of the same university and hospital research teams. With these living samples, scientists now have a powerful tool to study heart regeneration and test new therapies in a lab using real human heart cells.
Professor Sean Lal, the senior author of the study and a heart failure specialist, said, “Our ultimate goal is to use this discovery to make new heart cells and reverse heart failure. We’re already seeing exciting clues from proteins in these samples that are known to help mice regenerate heart cells. Now we want to apply that to human hearts.”
In summary, this research shows that the human heart has a small but real ability to heal itself after a heart attack. By studying this ability more closely, scientists hope to find ways to help the heart repair itself better and possibly even avoid heart failure in the future. This marks a hopeful new chapter in the fight against heart disease.
If you care about heart health, please read studies about top 10 foods for a healthy heart, and how to eat right for heart rhythm disorders.
For more health information, please see recent studies about how to eat your way to cleaner arteries, and salt and heart health: does less really mean more?
The study is published in Circulation Research.
Copyright © 2025 Knowridge Science Report. All rights reserved.
