Man who received first pig heart transplant dies

The first person to receive a genetically modified pig's heart has died two months after the groundbreaking operation, said the University of Maryland Medical Center on Wednesday.

David Bennett, 57, received the pig heart at the hospital on Jan 7 and had been recovering, but his condition began deteriorating several days ago, the hospital said in a statement. He died on Tuesday.

It is not clear yet what caused Bennett's death, according to the hospital, which said the transplanted heart performed "very well for several weeks without any signs of rejection".

Bennett was given "compassionate palliative care" when it became clear that he would not recover. He was able to communicate with his family during his final hours, the hospital said.

After the surgery, Bennett was able to spend time with his family and participate in physical therapy to help regain strength. He watched the Super Bowl with his physical therapist and he often told his caregivers how much he wanted to get home to see his dog Lucky.

"We are devastated by the loss of Mr. Bennett. He proved to be a brave and noble patient all the way to the end," said Bartley Griffith, who performed the operation, in a statement.

Bennett was deemed ineligible for a conventional heart transplant because of his severe condition. On New Year's Eve, the Food and Drug Administration granted an emergency authorization for the experimental surgery.

The pig heart he received had been modified to remove pig genes that trigger hyperfast rejection and human genes added to help the body accept the organ. Prior attempts at such transplants, or xenotransplantation, have failed largely because patients' bodies rapidly rejected the animal organ.

Significant step

Bennett's transplant is still considered a significant step forward because the pig heart was not immediately rejected and continued to function for well over a month, passing a critical milestone for transplant patients.

Bennett survived significantly longer with the gene-edited pig heart than one of the last milestones in xenotransplantation, when Baby Fae, a Californian infant, lived 21 days with a baboon heart in 1984. Her immune system rejected the heart.

"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," said Muhammad Mohiuddin, an expert in interspecies transplants who was involved in Bennett's care, on Wednesday.

Bennett's heart transplant surgery was one of several pioneering procedures in recent months to use organs from genetically modified pigs to replace human organs. Doctors are looking at the process in hopes of helping solve the shortage of donated human organs.

Some 41,354 people in the United States received a transplanted organ last year, including about 3,800 heart transplants, and more than half were kidneys, according to nonprofit United Network for Organ Sharing, which coordinates the nation's organ procurement efforts. More than 100,000 people are on the national waiting list for a transplant.