University of Maryland doctors in Baltimore perform first successful transplant of pig heart into human

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A Maryland man is doing well after surgeons and clinicians from the University of Maryland School of Medicine and the University of Maryland Medical Center performed the first successful transplant of a genetically modified pig’s heart Friday to save his life, officials from the health system said Monday.

After being diagnosed with terminal heart disease, the patient, 57-year-old David Bennett, had been deemed ineligible for a conventional heart transplant at the University of Maryland Medical Center and other transplant centers around the country. Doctors will monitor him in the hospital over the next several weeks or months to ensure that his body doesn’t reject the new heart.


Porcine heart transplants aren’t approved by the U.S. Food and Drug Administration, but the federal agency authorized the surgery Dec. 31 under its “expanded access” provision. Sometimes called the “compassionate use” provision, it is used when other treatment or therapeutic options aren’t available.

Bennett, who had been bedridden for much of the past few months due to a series of other operations, said he accepted the risks that came along with the experimental surgery.


“It was either die or do this transplant. I want to live,” he said in a statement before the operation. “I know it’s a shot in the dark, but it’s my last choice.”

Bennett’s team of doctors said the medical breakthrough can help health care providers solve the organ shortage crisis that leaves thousands without lifesaving treatment options each year.

“There are simply not enough donor human hearts available to meet the long list of potential recipients,” said Dr. Bartley P. Griffith, a distinguished professor at the medical school who performed the transplant, in a Monday statement. “We are proceeding cautiously, but we are also optimistic that this first-in-the-world surgery will provide an important new option for patients in the future.”

It’s still too early to say for sure, but Bennett’s surgery could open more doors and create new pathways forward for those waiting for not just hearts but also kidneys, livers and pancreases, said Dr. David Klassen, chief medical officer at the United Network for Organ Sharing, a national nonprofit contracted by the federal government to oversee and guide the country’s transplant network.

“These are very early days,” Klassen said Monday. “For the field of transplantation, it’s an important event. It’s a research endeavor, and there’s lots to learn, and there are things about it we don’t know to appreciate yet.”

Animal organ transplants, known as xenotransplants, are considered controversial by some and can pose considerable risks to patients and are not widely administered. In one particularly notable case, infant Stephanie Fae Beauclair, born with a significant heart defect, was given a baboon heart by doctors at a California hospital in 1984. Her case ended in tragedy 20 days later after her body rejected the new organ, leading to her death.

On Monday, Alka Chandna, vice president of laboratory investigations cases at the animal rights organization People for the Ethical Treatment of Animals, said such transplants are dangerous and a waste of resources that otherwise could be devoted to helping humans.

“The risk of transmitting unknown viruses along with the animal organ are real and, in the time of a pandemic, should be enough to end these studies forever,” Chandna said in a statement. “Animals aren’t toolsheds to be raided but complex, intelligent beings. It would be better for them and healthier for humans to leave them alone and seek cures using modern science.”


The risks are no doubt present, but they should be weighed against the risk of not doing anything, said Dr. Daniel J. Garry, professor of medicine at the University of Minnesota and a transplant cardiologist.

Garry said only about 2,000 people out of thousands more in need get heart transplants each year, and the majority of patients who need new organs will die within a year if they do not receive one.

There will be criticism attached to every new innovation, Garry said, but they should be balanced against human life.

“This can really open up a lot of wonderful opportunities and possibilities,” he said. “This is a hope that by engineering these pigs, they become acceptable to the human donor. This is a great opportunity, and we’re just going to have to wait and see what the survival is going to be.”

Pig hearts have long been studied as potential swaps for the human heart given their similarities. Some people already have received heart valves from pigs as replacements.

University of Maryland Medical System officials, in Monday’s news release, said physicians were confident that the transplant could buy the patient more time.


Griffith teamed with Dr. Muhammad M. Mohiuddin, a professor at the medical school and creator of the Cardiac Xenotransplantation Program, in studying this technique for the past five years. They used the genetically modified heart plus a combination of drugs meant to prevent the immune system from rejecting the new organ.

“This is the culmination of years of highly complicated research to hone this technique in animals with survival times that have reached beyond nine months,” Mohiuddin said. “The successful procedure provided valuable information to help the medical community improve this potentially lifesaving method in future patients.”

Mohiuddin is a career transplant researcher, according to the health system, and has demonstrated in peer-reviewed studies the viability of pig hearts in humans when genetically modified and combined with the right drugs.

Before agreeing to the experimental operation, Bennett had been admitted to the hospital for more than six weeks. He had been denied an artificial heart pump due to a life-threatening arrhythmia, or an irregular heartbeat. And, he had been placed on an extracorporeal membrane oxygenation machine, a device that pumps blood out of the body to give the vital organs time to recuperate during intense bodily stress. It is considered a last-chance therapy.

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The physicians and medical school were aided by Revivicor, a regenerative medicine company based in Blacksburg, Virginia, that provided the modified pig heart. The school of medicine also received a more than $15 million grant from Silver Spring-based Lung Biotechnology PBC to study the Revivicor organs in studies on baboons.

To genetically modify the heart, three genes were “knocked out,” according to the health system, that are responsible for causing an “antibody-mediated” rejection of pig organs in humans. Another one also was “knocked out” to prevent excessive growth of the pig heart tissue. Six human genes were inserted that encourage immune acceptance of the pig heart.


Top officials at the health care network thanked the patient for agreeing to be a part of history.

Dr. Mohan Suntha, president and CEO of the University of Maryland Medical System, said Bennett’s decision could save more lives in the future.

And Dr. Bert W. O’Malley, president and CEO of the Baltimore-based University of Maryland Medical Center, called the surgery a “historic, monumental step forward.”

“While we have long been at the forefront of research driving progress toward the promise of xenotransplantation as a viable solution to the organ crisis, many believed this breakthrough would be well into the future,” O’Malley said in a statement. “I couldn’t be more proud to say the future is now.”

O’Malley said the patient’s insurance covered his traditional hospital care, while the medical center and University of Maryland, Baltimore, contributed “collective funds,” which are reserved for uses such as unique patient care needs and innovation.

For the record

A previous version of this story misspelled Dr. Muhammad M. Mohiuddin's name. This story also has been updated to reflect that only about 2,000 people usually qualify for heart transplants each year, not organ transplants. The Sun regrets the errors.