First Successful Transplant of Porcine Heart Into an Adult Human

The first of its kind surgery was successfully completed in a 57-year-old patient with terminal heart disease. He received a transplant from a genetically-modified pig heart. The team of surgeons was from the University of Maryland School of Medicine in Baltimore.

The organ transplant demonstrated for the first time that a genetically-modified animal heart can function as a human heart without immediate rejection by the body. The patient Mr. David Bennet, 57 from Baltimore agreed to the procedure after entering the hospital 2 months prior with arrhythmia, and since he was not a viable candidate for the heart transplant list and his arrhythmia made him ineligible for an artificial heart pump.

The U.S. Food and Drug Administration granted emergency authorization for the surgery on New Year’s Eve through its expanded access (compassionate use) provision. The authorization to proceed was granted in the hope of saving the patient’s life. 

According to, about 110,000 individuals in the US are currently waiting for an organs transplant, and more than 6,000 patients die each year before getting one. Xenotransplantation could potentially save thousands of lives but does carry a unique set of risks, including the possibility of triggering a dangerous immune response. 

Three genes that are responsible for rapid antibody-mediated rejection of pig organs by humans were “knocked out” in the donor pig, and 6 human genes responsible for immune acceptance of the pig heart were inserted into the genome. Lastly, one additional gene in the pig was knocked out to prevent excessive heart tissue growth.

The patient has no signs of rejection of the pig’s heart 6 days after the procedure. 


University of Maryland School of Medicine. “Successful transplant of porcine heart into adult human with end-stage heart disease: First-of-its-kind transplant was patient’s only option for survival after being deemed ineligible for traditional transplant.” ScienceDaily. ScienceDaily, 10 January 2022. <>.

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Surgeons at the University of Maryland Medical Center transplanted a genetically altered pig heart into David Bennett.Credit: University of Maryland School of Medicine