Human heart produces new muscle cells after heart attack, Sydney researchers find

September 10, 2026 at 05:00 AM2 min

This digest was compiled by AI from multiple sources — links to the originals are below.

Researchers from the University of Sydney, the Baird Institute and Royal Prince Alfred Hospital have found that the human heart can produce new muscle cells after a heart attack. The discovery challenges the long-held assumption that heart muscle lost during an attack cannot regenerate. The findings were published in Circulation Research.

Key Facts

The human heart produces new muscle cells after a heart attack, according to a study published in Circulation Research.
Cardiovascular disease is the leading cause of death worldwide and accounts for 24 percent of all deaths in Australia.
A heart attack can destroy up to one third of the cells in the human heart.
Australia has approximately 144,000 people living with heart failure, while only about 115 heart transplants are performed each year.

Regenerative Discovery

Researchers from the University of Sydney, the Baird Institute and Royal Prince Alfred Hospital found that the human heart can produce new muscle cells after a heart attack. The discovery challenges the long-held assumption that heart muscle lost during an attack cannot regenerate. First author Dr. Robert Hume, from the Faculty of Medicine and Health and Charles Perkins Centre, said the heart produces new muscle cells despite being left scarred after an attack. Scientists had previously observed increased mitosis in the heart muscles of mice following a heart attack, but this is the first demonstration of the same phenomenon in humans.

Heart Attack Damage

Cardiovascular disease remains the leading cause of death worldwide, accounting for nearly a quarter of all deaths in Australia. A heart attack can destroy as many as one third of the cells in the human heart. Many patients eventually develop heart failure, a condition in which the heart can no longer pump blood effectively enough to meet the body's needs. A heart transplant is currently the only cure for heart failure, but only about 115 transplants are performed each year in Australia while approximately 144,000 people live with the condition.

Living Tissue Research

The research relied on a world-first approach involving heart tissue collected from living patients during bypass surgery. The heart's natural regenerative response is not currently strong enough to replace all of the muscle destroyed during a heart attack. Understanding how this process works could help researchers find ways to increase it, according to the study authors.