Maryland’s hospital who performed the procedure announced Wednesday that two months later, the original recipient of heart transplant from a porcine pig died.
David Bennett, age 57, was taken to the University of Maryland Medical Center. Doctors didn’t give an exact cause of death, saying only that his condition had begun deteriorating several days earlier.
Bennett’s son praised the hospital for offering the last-ditch experiment, saying the family hoped it would help further efforts to end the organ shortage.
“We are grateful for every innovative moment, every crazy dream, every sleepless night that went into this historic effort,” David Bennett Jr. said in a statement released by the University of Maryland School of Medicine. “We hope this story can be the beginning of hope and not the end.”
Since the beginning, many doctors have tried to save lives by using animal organs. Bennett, a handyman from Hagerstown, Maryland, was a candidate for this newest attempt only because he otherwise faced certain death—ineligible for a human heart transplant, bedridden and on life support, and out of other options.
After the Jan. 7 operation, Bennett’s son told The Associated Press his father knew there was no guarantee it would work.
Prior attempts at such transplants—or xenotransplantation—have failed largely because patients’ bodies rapidly rejected the animal organ. Maryland surgeons used a pig heart to replace the one that was destroyed by the virus.
The pig’s heart started to function initially, but the Maryland hospital kept updating Bennett that he was slowly improving. A video was released by the hospital last month showing Bennett, while in his hospital bed watching the Super Bowl with his physical therapist.
Bennett survived significantly longer with the gene-edited pig heart than one of the last milestones in xenotransplantation—when Baby Fae, a dying California infant, lived 21 days with a baboon’s heart in 1984.
“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,” Dr. Bartley Griffith, who performed the surgery at the Baltimore hospital, said in a statement.
Other transplant experts praised the Maryland team’s landmark research and said Bennett’s death shouldn’t slow the push to figure out how to use animal organs to save human lives.
“This was a first step into uncharted territory,” said Dr. Robert Montgomery of NYU Langone Health, a transplant surgeon who received his own heart transplant. “A tremendous amount of information” will contribute to the next steps as teams at several transplant centers plan the first clinical trials.
“It was an incredible feat that he was kept alive for two months and was able to enjoy his family,” Montgomery added.
There is a great need to find another source of organs. More than 41,000 transplants were performed in the U.S. last year, a record—including about 3,800 heart transplants. However, more than 106,000 Americans remain on the nationwide waiting list. Every year, thousands of people pass away before they can receive an organ. Many more are not added to this list because it is too long.
The Food and Drug Administration had allowed the dramatic Maryland experiment under “compassionate use” rules for emergency situations. Bennett’s doctors said he had heart failure and an irregular heartbeat, plus a history of not complying with medical instructions. His eligibility for human heart transplants requires that Bennett use immune-suppressing drugs or the other alternative of an implanted cardiac pump.
Transplant recipients are at high risk for organ rejection, infection and any other complications. Experts hope the Maryland team quickly publishes in a medical journal exactly how Bennett’s body responded to the pig heart.
From Bennett’s experience, “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. Muhammad Mohiuddin, scientific director of the Maryland university’s animal-to-human transplant program.
One next question is what evidence, from Bennett’s experience and some other recent experiments with gene-edited pig organs, may persuade the FDA to allow a clinical trial—possibly with an organ such as a kidney that isn’t immediately fatal if it fails.
Twice last fall, Montgomery’s team at NYU got permission from the families of deceased individuals to temporarily attach a gene-edited pig kidney to blood vessels outside the body and watch them work before ending life support. The University of Alabama at Birmingham surgeons went one step further and transplanted two gene-edited kidneys from a pig into an unconscious man. This was a step by step rehearsal of the operation that they plan to perform on living patients later in this year.
Since ancient times, pigs have been used for human medicine. This includes pig skin transplants and the implantation of heart valves. However, transplanting organs from pigs is more complicated than using high-quality tissue. Revivicor was the source of these gene-edited porcines used in these experiments. United Therapeutics is just one of several biotech firms that have been working on developing suitable pig organs to be transplanted.