Research breakthrough on heart-attack recovery

By ROSALEEN MacBRAYNE

New hope for heart-disease patients has come from research which skittles the long-held belief that the heart cannot repair itself.

The realisation that the body works to restore a damaged heart, much as it does other organs, such as the liver, is an exciting breakthrough, says Professor Harvey White, director of the coronary care unit at Green Lane Hospital in Auckland.

The discovery by a New York medical team, published this week in the New England Journal of Medicine, that the human heart can grow new muscle tissue was "a major departure from our accepted beliefs," he said yesterday.

"Here we have clear evidence that heart cells can regenerate."

Previous theories held that when a heart attack occurred the muscle died and a surviving muscle had to enlarge to compensate - not always successfully.

Professor White said it was possible that future techniques and therapies could help the heart reverse disease and high blood pressure.

Although a long way from becoming clinical practice, it was still a new and exciting area of research, and New Zealand experts would be keen to be involved.

The discovery that muscle cell division did not stop soon after birth came when researchers at the New York Medical College did a novel study of eight heart transplants, all to male recipients from female donors.

Because female cells lack the Y chromosome that carries the genetic code for male characteristics, the team could determine which cells came from the donor and which belonged to the recipient.

But the researchers discovered cells throughout the female heart that contained a Y chromosome. It was unclear whether those cells came from remnants of the old male heart and migrated to the new one, or whether they were originally highly versatile stem cells from the men's bone marrow and moved to the heart in an attempt to repair the damage from surgery.

In an editorial in the Journal, Dr Roberto Bolli of Kentucky's University of Louisville said the speed and degree to which the cells of the host worked to repair and remodel the new heart were surprising, revealing previously unknown aspects of cardiac biology.

The Journal editors, Dr Robert Schwartz and Dr Gregory Curfman, said the discovery of techniques to help the heart reverse disease was now a realistic goal.

nzherald.co.nz/health