He passed away March 8, according to a statement from the University of Maryland Medical Center (UMMC), Baltimore, where the transplant was performed.
Mr. Bennett received the transplant on January 7 and lived for 2 months following the surgery.
Although not providing the exact cause of his death, UMMC said Mr. Bennett’s condition began deteriorating several days before his death.
When it became clear that he would not recover, he was given compassionate palliative care and was able to communicate with his family during his final hours.
“We are devastated by the loss of Mr. Bennett. 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,” Bartley P. Griffith, MD, who performed the transplant, said in the statement.
“We are grateful to Mr. Bennett for his unique and historic role in helping to contribute to a vast array of knowledge to the field of xenotransplantation,” added Muhammad M. Mohiuddin, MD, director of the cardiac xenotransplantation program at University of Maryland School of Medicine.
Before receiving the genetically modified pig heart, Mr. Bennett had required mechanical circulatory support to stay alive but was rejected for standard heart transplantation at UMMC and other centers. He was ineligible for an implanted ventricular assist device due to ventricular arrhythmias.
Following surgery, the transplanted pig heart performed well for several weeks without any signs of rejection. The patient was able to spend time with his family and participate in physical therapy to help regain strength.
“This organ transplant demonstrated for the first time that a genetically modified animal heart can function like a human heart without immediate rejection by the body,” UMMC said in a statement issued 3 days after the surgery.
Thanks to Mr. Bennett, “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 Dr. Mohiuddin. “We remain optimistic and plan on continuing our work in future clinical trials.”
The patient’s son, David Bennett Jr, said the family is “profoundly grateful for the life-extending opportunity” provided to his father by the “stellar team” at the University of Maryland School of Medicine and the University of Maryland Medical Center.
“We were able to spend some precious weeks together while he recovered from the transplant surgery, weeks we would not have had without this miraculous effort,” he said.
“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,” he added.
A version of this article first appeared on Medscape.com.