Stem cells can repair a damaged heart and potentially halve the number of people dying from heart failure, scientists have shown, in a major breakthrough for regenerative medicine.

For more than a decade scientists have been convinced that stem cells were the future of organ repair because they can become any cell in the body, reversing damage which was thought to be permanent. Finding new ways to treat organ failure is critical because there is a growing shortage of donor organs in the UK.

Now, in the largest trial ever conducted, doctors in the US have proven that even the most serious cases of heart failure can be repaired using stem cells harvested from a patient’s own bone marrow.

End-stage patients, whose only hope was a heart transplant, were treated with stem cells in a single operation. Doctors found the group were 37 per cent less likely to have been admitted to hospital in the 12 months following the operation and half as likely to have died than those on placebo.

The procedure takes just two hours and most patients were discharged a day after surgery.

"For the last 15 years everyone has been talking about cell therapy and what it can do. These results suggest that it really works," says lead author and cardiac surgeon Dr Amit Pate, director of Cardiovascular Regenerative Medicine at the University of Utah.