The University of Maryland Medical Center announced yesterday that David Bennett, the first successful recipient of a transplanted porcine heart, died at the age of 57. An exact cause of death was not provided, though the physicians noted that his condition had been deteriorating over the previous several days.

The fact that the transplanted heart extended Bennett’s life by two months is significant progress since 1984, when an infant (“Baby Fae”) born with a fatal heart defect survived for 21 days after receiving a baboon heart transplant. For Bennett’s transplant, the surgical team used an organ from a pig that was gene-edited to increase the human recipient’s likelihood of accepting the new heart.

Faced with few alternatives as he was ineligible for a human heart transplant, David Bennett was an ideal candidate for the groundbreaking procedure. Bennett and his family were aware going into the surgery that there was no guarantee that it would work. David Bennett Jr. has expressed gratitude to the University of Maryland physicians and to the scientific community in general for giving his father this opportunity, saying, “We hope this story can be the beginning of hope and not the end.”