A 57-year-old man with fatal heart disease died on Tuesday at the University of Maryland Medical Center (UMMC), according to the hospital. He was the first person to get a heart from a genetically modified pig.
On January 7, David Bennett received his transplant.
According to the hospital, his condition begins to deteriorate some days ago, and he was given "compassionate palliative care" after it become evident that he would not recover.
Dr. Bartley Griffith, director of the UMCC cardiac transplant programme, said in a videotaped statement that Bennett "wasn't able to overcome what turned out to be the catastrophic debilitation" caused by the heart failure he had before the transplant.
According to the hospital, Bennett was able to interact with his family during his final hours.
Bennett arrived at UMMC in October as a patient and was put on a heart-lung bypass system, but he was ruled ineligible for a traditional heart transplant.
Bennett's kid described the treatment as "miracle" after he received a pig heart that had been modified to prevent rejection using new gene editing technologies.
The operation was Bennett's last resort.
Griffith said the transplanted heart worked "beautifully."
Pigs have long been considered a viable supply of organs for transplantation due to their physical similarities to humans in many aspects. Attempts at pig-to-human transplants have previously failed due to genetic variations that caused organ rejection or viruses that created a danger of infection.
"Mr. Bennett was fully apprised of the surgery's hazards and that the technique was experimental with uncertain dangers and benefits before consenting to accept the transplant," the hospital said.
"The evidence that it was conceivable - that we were able to take a genetically altered organ and watch it perform beautifully for nine weeks," Griffith added.