Heart May Be Able to Mend Itself After Heart Attack
June 6, 2001 -- Conventional medical wisdom takes another hit with news that heart muscle cells appear capable of regrowing after a heart attack, suggesting that it may be possible to coax the heart into repairing itself, report researchers in what's being hailed as a landmark study published in the June 7 issue of The New England Journal of Medicine.
"It has long been assumed that when the heart is damaged -- such as after a heart attack -- heart muscle cells do not regenerate and the damage is permanent. This assumption has been challenged in recent years by evidence that heart muscle cells may in fact regenerate. Now, this latest research provides the most dramatic and clear-cut demonstration to date of heart cell regeneration after cardiac injury," according to a written statement by Claude Lenfant, MD. Lenfant is the director of the National Heart, Lung, and Blood Institute, which jointly funded the study with the National Institute on Aging.
Building on their earlier work, Piero Anversa, MD, and colleagues at New York Medical College in Valhalla, N.Y., examined the hearts of people who died within two weeks of a heart attack and compared them with hearts from similar people who died of other causes. They were looking for evidence that the heart muscle cells in the damaged organs were still capable of dividing, indicating that they had the potential to grow into new, mature heart muscle.
They found that in areas of the heart bordering parts that been damaged by heart attack, the number of cells capable of dividing was about 84 times higher than in the same area of undamaged hearts. And when they looked at a portion of the attack-damaged hearts that was far from the injury site, they found that the number of potential replacement cells was still about 28 times higher than in comparable regions of the other hearts. They also found other signs that there were heart cells either actively dividing or getting ready to do so in the hearts of people who had suffered a cardiac event.
The findings add to the growing body of evidence that damage from heart attacks may be at least partly reversible, but getting from that observation to actual therapies may take some doing, says a heart researcher who commented on the study in an interview with WebMD.
"If it worked really well, all heart attacks would be cured, and obviously that's not the case" says David Finkelstein, PhD, director of basic cardiovascular research at the NIA. "If I had to say what's important about this, it is that knowing that heart cells can divide leads us now to look for ways that cells can divide. But how long that's going to take is anybody's guess."