David Bennett, who suffered from terminal heart disease, survived for two months after the operation in the United States.
But his condition began to deteriorate several days ago, his doctors in Baltimore said, and the 57-year-old died on March 8.
Mr. Bennett knew the risks associated with the surgery, acknowledging before the procedure that it was “a shot in the dark.”
Doctors at the University of Maryland Medical Center obtained a special waiver from the U.S. medical regulator to perform the procedure, on the grounds that Mr. Bennett — who was not eligible for a human transplant — would otherwise have died.
He had already been bedridden for six weeks prior to the operation, attached to a machine that kept him alive.
Bennett underwent the surgery on Jan. 7, and doctors say that in the weeks that followed, he spent time with his family, watched the Super Bowl and talked about wanting to go home with his dog, Lucky.
But his condition deteriorated, leaving doctors “devastated.”
“He turned out to be a brave and noble patient who fought to the end,” surgeon Bartley Griffith, who performed the transplant, said in a statement released by the hospital.
But Bennett’s son, David Jr, said he hoped his father’s transplant would be “the beginning of hope, not the end,” according to the AP news agency.
“We are grateful for every groundbreaking moment, every crazy dream, every sleepless night that contributed to this historic effort,” he added.
Dr. Griffith previously said the surgery would bring the world “one step closer to solving the organ shortage crisis.” Currently, 17 people die every day in the United States while waiting for a transplant, and more than 100,000 are believed to be on the waiting list.
The possibility of using animal organs for so-called xenotransplantation to meet the demand has long been considered, and the use of pig heart valves is already common.
In October 2021, surgeons in New York announced that they had successfully transplanted a pig kidney into a person. At the time, the operation was the most advanced experiment in the field to date. However, the recipient on this occasion was brain dead with no hope of recovery.
The biggest obstacle to the use of organs from another species is “hyperacute rejection”. The body sees the tissue as so foreign that it begins to kill the donated organ within minutes.
The hope was that the 10 genetic changes made to the pig meant that its organs would be acceptable to the human body.
It was a nervous moment when the heart went in, but there was no hyperacute rejection and that monumental barrier had been breached.
When I spoke to the surgical team a month after the surgery, they told me that there was still no sign of rejection and that the donated heart was working like a “Ferrari engine.” But they cautioned that he himself was still fragile.
Exactly what has happened since and the precise cause of Mr. Bennett’s death is unclear.