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.
Heart failure occurs when the heart can no longer pump enough oxygenated blood around the body at the correct pressure, usually because the muscle has become too weak or stiff to work properly.
In the short term it leads to breathlessness, fatigue and swollen ankles but in the long run the major organs will shut down without enough oxygen, eventually leading to death.
Around 900,000 people in the UK have been diagnosed with the condition and up to 40 per cent die within a year.
Drugs to help keep the blood vessels open and lower blood pressure are often prescribed to help manage the condition, but for many patients a heart transplant is the only option. Many die waiting for an organ to become available.
But the researchers say stem cell therapy could one day offer an alternative to a transplant.
The trials involved 126 patients from 31 hospitals across the US. Each was assigned stem cell therapy or placebo and the doctors did not know which they would be getting.
A small amount of bone marrow was drawn from each patients from which two types of stem cell were extracted, and their number increased in the lab.
After scanning the patient’s heart to see where the damage was greatest, the stem cells were then delivered to those areas using a catheter.
The group were then followed for 12 months with doctors monitoring deaths, hospitilsations and unplanned clinic visits. During that period eight patients died who had been given a placebo, compared with four who were on the stem cell treatment.
82 per cent of patients who did not have the therapy needed hospital treatment during that time, compared with 51 per cent of the stem cell patients.
Although the study found there was only very small improvements in overall heart function including performance in an exercise tolerance test, scientists think a larger sample size may show larger benefits and are hoping to move to phase 3 trials with a greater number of patients.
Professor Jeremy Pearson, Associate Medical Director at the British Heart Foundation, said:“There are over half a million people in the UK, and millions around the world living with debilitating heart failure.
“Treatments are limited and the only ‘cure’ is a heart transplant. Regenerative treatments that repair the damage caused by a heart attack, which often leads to heart failure, are urgently needed.
“Over the last decade there has been a series of trials involving injecting a patient’s own bone marrow-derived cells to help repair the failing heart. Most studies have been small and overall shown the procedure is safe but the clinical benefit, if any, has been marginal.
“Bone marrow stem cell therapy appears to be safe but using it to improve heart function and the quality of life for patients depends on further research.”
The results of the trial were presented at the American College of Cardiology annual meeting and published in The Lancet.
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