UK experts say an artificial pump that rejuvenates dying hearts could save thousands of lives.
The heart can become enlarged in heart failure
Three-quarters of the patients who took part in a trial of the mechanical heart at the Royal Brompton and Harefield Hospital made a recovery.
The temporary pump, combined with a cocktail of drugs, lets the failing heart rest and repair itself.
Surgeons told the New England Journal of Medicine the therapy could remove the need for heart transplantation.
The mechanical devices, known as Left Ventricular Assist Devices (LVADs), are currently used in patients with very severe heart failure whilst they await transplantation.
But a shortage of donor organs means some never get a new heart.
The new therapy has the potential to ease the pressure on the waiting list while also offering patients a better alternative to a donor heart - their own, healthy heart, say the researchers.
The device is implanted by surgeons
For the study, experts from Imperial College London and the Royal Brompton and Harefield NHS Trust gave the full combination therapy to 15 severely ill patients.
Of these 15, 11 recovered. Eight of these patients were alive and free of heart failure or transplantation more than four years later.
Professor Sir Magdi Yacoub, from the Heart Science Centre at Imperial and the Royal Brompton and Harefield NHS Trust, said: "We are impressed by the dramatic, sustained improvement in the condition of these severely ill patients.
"The improvement observed was far greater than what has been reported to date for any other therapy.
"The study also highlights the fact that 'end stage' heart failure can be reversed and that the heart has the capacity to regenerate itself.
"It therefore stimulates the search for other strategies and more therapeutic targets in this expanding field of regenerative therapy."
The British Heart Foundation, which supported the research, stressed that the technique was only suitable for certain patients.
Professor Peter Weissberg, medical director of the BHF, explained it could help some who develop severe heart failure as a result of a disease which weakens their heart muscle, but not those with the more common coronary heart disease, which damages the heart as a result of a lack of blood supply.
He added: "The study raises several important questions which will need answering in future clinical studies - we need to know exactly what part of this treatment regimen is responsible for the recovery of heart function, and which patients can benefit from it."
The LVAD takes on the work of one of the heart's four chambers, the left ventricle, which pumps oxygen-rich blood from the heart around the body.