American Lawrence Faucette, 58, became the second person in the United States to have a genetically modified pig heart operated on. He died on Monday, six weeks after the procedure, the University of Maryland School of Medicine announced.
The heart appeared to be working and healthy for the first month, but then the body began to show signs of organ rejection, according to doctors.
The first patient to have a pig heart implanted at the same university survived for two months.