A man who received a genetically modified pig heart in January 2022 has passed away.
The man, David Bennett, was 57-years-old. He passed away at the University of Maryland Medical Center only two months after he received his pig heart on January 7.
Doctors Mourn The Loss Of First Man To Receive A Genetically Modified Pig Heart Transplant

The hospital released a statement saying that his condition began deteriorating several days ago.
“After it became clear that he would not recover, he was given compassionate palliative care,” they said. “He was able to communicate with his family during his final hours.”
His doctors and his son, while grieving, were grateful for the opportunity to try this scientific breakthrough. The previous long-term survivor of an animal heart transplant was a California infant known as Baby Fae, who lived for 21 days with a baboon’s heart in 1984.
“We are grateful for every innovative moment, every crazy dream, every sleepless night that went into this historic effort,” his son, David Bennett Jr., said in the hospital’s statement. “We hope this story can be the beginning of hope and not the end.”
Although Bennett had congestive heart failure and was not approved for a human heart transplant, the doctors managed to obtain emergency authorization for the experimental surgery to save his life. Since the body usually rejects a foreign organ, the doctors said that the fact that he was able to survive the procedure at all was nothing short of a miracle.
Maryland Man Receives Pig Heart Transplant To Control ‘Uncontrollable Arrhythmia’

According to his son, Bennett began having severe chest pains last October. Otherwise, he was reported to be mostly healthy throughout his life. A physical therapist at the University of Maryland Medical Center said that Bennett’s symptoms of severe fatigue and shortness of breath were so severe that he could not walk up three steps on his own.
Bennett spent months trying to save his own heart, to no avail. He was not able to get an artificial heart pump installed because of his uncontrollable arrhythmia. Bennett knew that his odds to get a heart transplant were not good. Over three thousand Americans qualify for a heart transplant, and approximately twenty percent of those who are added to the waitlist pass away before a new heart becomes available.
Although Bennett did not qualify for a heart transplant because he did not follow doctor’s orders and had missed medical appointments, he realized that the experimental surgery might be the only way that he was going to get to leave the hospital.
“He knew that this was his best option,” David said. “He’s a fighter and has a desire to live.”
The History Of Gene-Editing Pig Organs Started In Baboons

The University of Maryland Medicine team, which is co-led by Dr. Muhammad Mohiuddin, is no stranger to gene-editing pigs, although January’s experimental surgery was the first time that they tried the procedure in a human being.
The medical team already had experience keeping animals like baboons alive for as long as nine months. Although the baboons did pass away less than a year after the surgery, it was said that they died of something other than an immune rejection.
Before the team could begin the experimental surgery they first had to get approval from the United States Food and Drug Administration. They not only had to provide extensive information about Bennett, but about the pig itself.
The pig, who was unnamed, was provided by a Blacksburg, Virginia, company called Revivicor, which specifically raises genetically modified pigs with the hopes that their organs will one day be able to be used for transplant.

There are over 100,000 genes in a pig, and Mohiuddin requested that they only change ten of them in order to make the pig heart adaptable to live inside a human’s body. Three genes that might have caused an immune rejection were turned off, and six human genes were added to reduce the risk of rejection and prevent the blood from coagulating. Scientists also turned off another final gene to prevent the pig from growing too large.
Although the pig that donated its heart was 240 pounds, it would have likely weighed around 450 pounds if that gene had not been turned off. Scientists have learned through various studies, that, with that gene in place, the organ would have kept growing. In the case of baboons, the transplanted pig hearts eventually got to a point where they grew too large for their chests.
Although Bennett has unfortunately passed away, it does inspire hope that animal-to-human transplant surgeries will have the opportunity to save millions of lives with more research.