Stem cell study bids to ‘mend broken hearts’

Scientists are to fight the growing epidemic of heart failure through regenerative medicine – using stem cells and other technologies to repair or replace damaged tissues.

One result could be a pill to “mend broken hearts” within five to 10 years.

The British Heart Foundation, which funds most cardiac research in the UK, is launching a £50m Mending Broken Hearts appeal to pay for a wide-ranging new programme of regenerative medicine.

Heart failure usually results from damage to cardiac muscle during a heart attack. Because the population is ageing and so many more people are surviving heart attacks, the number of patients in Britain with heart failure has risen over the past 50 years from an estimated 100,000 to 750,000 today.

As the heart no longer pumps properly, patients are often left housebound and fighting for breath. Even getting out of bed or eating a meal can be difficult.

“We’ve made great strides in medical research to better diagnose and treat people with all kinds of heart problems, but the biggest issue that still eludes us is how to help people once their heart has been damaged by a heart attack,” said Professor Peter Weissberg, BHF medical director.

“Scientifically, mending human hearts is an achievable goal and we really could make recovering from a heart attack as simple as getting over a broken leg.”

The research programme is inspired by the fact that cardiac regeneration already occurs in nature. Adult zebrafish and frogs, for example, grow back fully functioning heart muscle and blood vessels to replace damaged tissue. In humans and other mammals, heart regeneration no longer occurs after infancy, though it does take place in other muscles.

One approach is to regenerate the heart directly with injections of stem cells – unspecialised human cells with the capability of turning into heart tissue.

But an indirect alternative is gaining scientific support, said Paul Riley, professor of molecular cardiology at University College London. This involves finding drugs that will awaken the dormant stem cells that are believed to exist within adult heart muscle. For example, a protein called thymosin-beta-4 activates cardiac stem cells in laboratory mice.

Prof Riley said the ideal would be to discover a cocktail of “small molecules” that someone with heart failure could take by mouth – a pill that could regenerate tissue by mobilising the patient’s own stem cells.