Stem-cell hope for victims of heart attacks

The work by doctors in the United States raises the prospect of restoring healthy heart tissue to patients suffering the debilitating impact of heart failure.

It is the latest development using stem cells which in decades to come could open up new possibilities for millions by restoring and repairing damaged organs and tissues.

For heart patients, it would represent a remarkable further boost on top of major improvements in heart care in the last four decades which have already seen a dramatic improvement in their prospects thanks to better drugs and surgical care.

The study, published online by The Lancet medical journal, found the extent of normally permanent scarring on the heart was halved and the treatment even led to the growth of new heart muscle.

However, it produced no significant change in “ejection fraction” – a measure of the heart’s pumping capacity.

The trial recruited a total of 25 patients with an average age of 53 who had all suffered heart attacks in the previous month.

Each underwent extensive tests to pinpoint the exact location and amount of scar tissue in their hearts.

Seventeen received coronary artery infusions of 12 to 25 million stem cells derived from healthy tissue which was taken from their own hearts. The remaining eight underwent standard post-heart attack care.

A year later, the proportion of the heart left scarred in the stem cell-treated patients had been reduced from 24 per cent to 12 per cent. No change was seen in patients who did not receive the treatment.

Doctors today hail the findings as offering a potential way forward for treating heart patients who have suffered a heart attack.

Prof Eduardo Marban, director of the Cedars-Sinai Heart Institute in Los Angeles, who led the US team, said: “The effects are substantial, and surprisingly larger in humans than they were in animal tests.

“This discovery challenges the conventional wisdom that, once established, scar is permanent and that, once lost, healthy heart muscle cannot be restored.”

The study, which was chiefly conducted to evaluate safety, follows a similar trial by US scientists at Harvard Medical School and the University of Louisville.

That study, which used a different kind of heart stem cell, produced a 12 per cent average increase in ejection fraction.

Future work will need to see if stem cell treatment can bring any long-term improvement in patients who experience heart failure after a heart attack.

This occurs when a weakened heart is not strong enough to pump sufficient blood around the body, causing breathlessness and exhaustion.

Prof Jeremy Pearson, associate medical director at the British Heart Foundation, said: “These cells have been proven to form heart muscle in a Petri dish but now they seem to be doing the same thing when injected back into the heart as part of an apparently safe procedure.

“It’s early days, and this research will certainly need following up, but it could be great news for heart attack patients who face the debilitating symptoms of heart failure.”

The charity’s Mending Broken Hearts appeal aims to raise £50m for research into regenerative heart treatments.

Fifty years ago there were only around 100,000 people in the UK with heart failure.

But an ageing population and more people surviving heart attacks now mean there are about 750,000 with the condition and numbers will only grow as the obesity epidemic worsens.