His doctors in Maryland, US, had offered the grandfather-of-five one last glimmer of hope to prolong his life: a replacement heart from a genetically modified pig.

News of his operation made headlines around the world, with Mr Bennett saying it was “do or die” and that he accepted it was a “shot in the dark”.

The operation was initially a success. The genetically modified heart, which had been designed to be small enough for a human and not to be rejected, was functioning well.

Surgeon Dr Bartley Griffith received special permission from the US Food and Drug Administration on Dec 31, 2021 to try and save Mr Bennett’s life with the procedure.

“We are devastated by the loss of Mr Bennett,” Dr Griffith said

“He proved to be a brave and noble patient who fought all the way to the end. We extend our sincerest condolences to his family.

Steadfast will to live

“Mr Bennett became known by millions of people around the world for his courage and steadfast will to live.”

The full details of the case are expected to be published in a medical journal soon.

However, the University of Maryland Medical Centre, where the operation was performed on Jan 7 and where he had been treated since October 2021, said the heart performed well for several weeks with no signs of rejection.

He remained there for monitoring until his death, receiving physical therapy to regain his strength. He watched the Superbowl, the finale of the US American Football season, on Feb 13.

The hospital said he fell ill several days ago and deteriorated rapidly. He was moved to palliative care before his death on Tuesday.

After Mr Bennett’s operation it emerged he had assaulted a man at a bar in 1988, leaving him paralysed.

He was convicted of stabbing the man several times and served six years in prison while the victim, Edward Shumaker, was left in a wheelchair with physical and mental impairments for 19 years before dying aged 40.

Mr Shumaker’s sister, Leslie Downey, told the Washington Post she wished the second chance at life that Mr Bennet received had instead gone to a “deserving recipient”.

The pioneering heart came from a genetically-modified pig grown by Revivicor, a spin-off company from PPL Therapeutics which created Dolly the sheep, the first cloned mammal.

The same company provided swine kidneys which were transplanted into a brain dead patient in January, in another world first. The patient, Jim Parsons, 57, of Alabama, was put forward for the procedure by his family to further medical knowledge, knowing Mr Parsons would still die following a fatal motorbike accident.

But with Mr Bennett there was a sliver of hope that his transplant could offer him a longer life beyond his otherwise bleak prognosis. His case will help inform future policy decisions and enable scientists and doctors to refine the xenotransplant process.

Beginning of hope

“As with any first-in-the-world transplant surgery, this one led to valuable insights that will hopefully inform transplant surgeons to improve outcomes and potentially provide lifesaving benefits to future patients,” Dr Griffith said.

Mr Bennett’s son, David Bennett Jr, said: “We hope this story can be the beginning of hope and not the end.

“We also hope that what was learned from his surgery will benefit future patients and hopefully one day end the organ shortage that costs so many lives each year.”

Mr Bennett’s case is undoubtedly a watershed moment in transplantation and his operation will likely be widely considered as a resounding success, despite his death.

The first patient to receive a human heart transplant died after 18 days, but today hundreds of these transplants are performed every year in the UK alone.

Dr Luciano Potena, president of the European Society for Organ Transplantation, told The Telegraph: “I would say that [the operation] was successful in that we learned that it’s feasible.

“There are a lot of open questions that need answering, like why the patient died and what is the cause of death.

“On the one hand, this a revolutionary approach that in the future may lead to a real improvement of quality of life of patients needing transplantation and length of life.

“But on the other hand, there are a lot of issues that need to be tackled, medical issues because the patient died soon, but also an ethical framework that needs to be taken into account.”

Mr Bennett’s case report will be scrutinised worldwide by academics and clinicians for years to come. Knowledge accrued from the case of the first live and cognisant patient to receive an animal organ will contribute to ending the vast organ shortage that claims thousands of lives every year.

While ethical issues abound, academics believe his case means xenotransplants could be a reality in ten years time and academics have called for urgent reform of legislation to keep up with the rapidly moving field.