The first person to receive a pig heart transplant has died two months after the historic surgery, according to the University of Maryland medical centre.
Surgeons in the US state successfully implanted a pig's heart into a 57-year-old man back in January and had said the weeks following would be vital.
The experimental surgery marked the first of its kind and raised hopes that cross-species organ donation could aid the current global shortage.
The patient, 57-year-old David Bennett, worked as a handyman in Maryland and said he knew there was no guarantee the operation would work.
Medics confirmed that he had terminal heart disease and was ineligible for a human heart transplant.
The vital organ was genetically modified and given to David as a last clutch of life.
Speaking at the time of the procedure, Mr. Bennett had said: “It was either die or do this transplant. I want to live. I know it’s a shot in the dark, but it’s my last choice.”
Doctors caring for David said he was performing well for weeks after the surgery, and that there were no immediate signs of rejection.
However, in a statement released today, they confirmed: "His condition began deteriorating several days ago. After it became clear that he would not recover, he was given compassionate palliative care.
“He was able to communicate with his family during his final hours.”
It went on to praise how brave Mr. Bennett was throughout, and that thanks to him, doctors and scientists have gained invaluable insights into the procedure and its potential success.
"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.
"We have gained invaluable insights learning that the genetically modified pig heart can function well within the human body while the immune system is adequately suppressed.”