US researchers have shown that stem cell therapy could help repair failing hearts.
Stem cells could help repair damaged hearts
Scientists at the University of Pittsburgh School of Medicine looked at 20 patients with heart failure.
They found those who had stem cells injected into damaged parts of their hearts were able to pump more blood than those who had surgery alone.
Researcher Professor Robert Kormos said the findings could 'revolutionise' treatment.
Previous studies have shown the potential of adult stem cells to encourage heart muscle and blood vessel growth.
This is the first study that actually demonstrates this.
Stem cells are immature cells that can be programmed to grow as other types of tissue, such as heart muscle.
All patients involved in the study suffered from severe heart failure.
This means their hearts were unable to pump blood efficiently.
Researchers looked at patient's 'ejection fraction' - a standard measure of heart performance, determined by the total amount of blood pumped out by the left ventricle.
A normal person has an ejection fraction of 55%.
When the trial began, all patients had ejection fractions of less than 35%.
All patients underwent heart by-pass surgery.
During the operation, selected patients were given two types of stem cells taken from their hip bones.
The cells were injected into 25 to 30 sites where the heart muscle was damaged.
After six months, the group receiving stem cell therapy had an average ejection fraction rate of 46.1%.
Those who had surgery alone had an average of only 37.2%.
The treatment did not appear to cause any serious side effects, such as abnormal heart rhythms.
Professor Kormos said: "These results encourage us to aggressively pursue cellular therapies as an option for congestive heart failure."
"It will revolutionise our approach, which is largely palliative, to one that is truly regenerative."
Dr Amit Patel, from the University of Pittsburgh School of Medicine presented the findings at a meeting of the American Association for Thoracic Surgery in Toronto, Canada.
He said further investigation would be needed to replicate the results and look at the cellular effects of the therapy.
The team are continuing the trial with 40 patients, while a separate one, looking at patients with inoperable heart failure is under way.
Around 650,000 people in the UK suffer from heart failure each year.
Belinda Linden, Head of Medical Information for the British Heart Foundation, said: "This is particularly significant as the incidence of heart failure is increasing.
"Most current treatments are aimed at relieving the symptoms; if we can actually repair the heart itself this will be a signficant advancement.
"However, it must be remembered that this treatment is still experimental and we need to know much more about the way that stem cells work to be able to understand how they provide their beneficial effect."