BALTIMORE — Doctors at the University of Maryland School of Medicine have concluded that a man who received a first-of-its-kind pig-heart transplant in January died two months later from heart failure. Though the reason for the failure remains under investigation.
The man, David Bennett, was able to get out of bed, begin rehabilitation and spend time with his family in the weeks after the transplant at the University of Maryland Medical Center. His doctors say that makes the effort a success.
All the subsequent information gathered will be applied when they are ready for the next so-called xenotransplant patient. That includes clues about how to prevent issues that may have contributed to the heart failure, including a reaction to a drug aimed at preventing rejection.
“We are still trying to figure out what went wrong; we don’t have a single answer,” said Dr. Muhammad M. Mohiuddin, co-leader of the pig heart study and professor of surgery and scientific/program director of the cardiac xenotransplantation program in the medical school.
“But we don’t consider this a setback,” he said. “We consider that he lived through the surgery the first win. When he seemed to be recovering and doing well for two months, we really considered thought that was a huge success. If we could have identified the reason his heart gave out suddenly, he might have walked out of the hospital.”
An autopsy found Bennett’s body didn’t show traditional signs of rejecting the heart. Rather, doctors found a thickening and then stiffening of the heart muscle, perhaps a reaction to a drug used to prevent rejection and infection. That made it unable to relax and fill with blood as it’s supposed to.
According to the doctors’ study, which was published in June in the New England Journal of Medicine, they also found DNA from a latent infection in the specially reared pig that evaded precautions and screening. It’s still not clear whether that contributed to the heart failure.
The 57-year-old Bennett had been bedridden and hooked up to a life-saving heart-lung bypass machine for eight weeks with end-stage heart failure prior to the transplant with the genetically modified pig heart. He was not eligible for a traditional heart transplant and federal regulators granted him a so-called “compassionate use” exemption to have the experimental pig-heart transplant. Such animal organ transplants are not approved by the U.S. Food and Drug Administration.
Mohiuddin said all the findings will lead to changes to practices and techniques in future trials. Patients and their families have been contacting him and other doctors since the transplant was announced, but there is no timeline for another transplant.
“There is a patient population that could benefit from this, and many have offered, volunteered for the procedure,” he said. “Before we satisfy anyone else, we have to be satisfied what we have learned can be applied to the next one.”
The transplant was the result of a $15.7 million research grant from the Virginia-based biotech company Revivicor to study its genetically modified pig UHearts in baboons.
About 110,000 Americans are currently waiting for an organ transplant, with more than 6,000 dying annually while they’re on the list, according to federal figures.
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