'Science fiction is fact' with pill that helps heart rebuild itself

A PILL that enables damaged hearts to repair themselves could be a reality within ten years, thanks to a British stem-cell breakthrough.

Scientists have discovered that a natural embryo molecule can awaken dormant repair cells in adult hearts. It could form the basis of a drug that helps destroyed heart muscle to be rebuilt after a heart attack.

Tests on mice showed it was possible to improve the pumping efficiency of damaged hearts by 25 per cent. Half that level of benefit could transform the lives of millions of people suffering the devastating after-effects of a heart attack.

Professor Peter Weissberg, medical director of the British Heart Foundation, which funded the research led by University College London scientists, said: "Even five years ago, people would have said this is science fiction, science fantasy."

Until recently, experts agreed that the heart was inherently irreparable. Once it was damaged, it stayed damaged.

Then research on the changes that occur in embryos developing in the womb led to a rethink.

Scientists learned that stem cells which build the heart in the growing embryo are also present in adults, but dormant.

The breakthrough discovery was that a peptide - a protein building block - called thymosin beta 4 (Tbeta4) which is normally active in the embryo could "re-awaken" the adult stem cells.

Scientists found they could "prime" the hearts of healthy mice for repair by injecting them with Tbeta4.

A "booster" dose of the peptide after a subsequent heart attack reactivated the stem cells and marshalled them into action. Not only did they build new heart muscle, but the cells were electrically "bonded" with existing muscle and able to contract in sync with the rest of the organ. The results were published online today in the journal Nature.

Researchers are now looking at ways of "tweaking" the process to make it more efficient - possibly by finding more powerful alternative molecules that have a similar effect as Tbeta4.

At a "conservative" estimate, they believe a practical treatment could be available in tenyears.

This might be an injection or even a pill given to people known to be at risk of a heart attack. They could be patients who suffer from angina, individuals with high blood pressure or high cholesterol, or those whose close relatives have had heart trouble.