"Experiments have been done on a monkey's heart for heart transplants for humans in the past, but they did not work out. However, the experiment on a pig's heart did," explained Dr. Mohiuddin, who is originally from Karachi and a graduate of the Dow University of Health Sciences.
"We examined all animals to find out which of them is closest to humans and found a pig suitable for the experiment," he added.
The doctor explained that the pig's heart had been genetically modified to better suit the human body using genes from different pigs.
The 57-year-old patient, an American citizen, is reportedly doing well after the procedure, although he will need to remain closely monitored by doctors. He is the first person in the world to receive a transplant from a genetically modified pig's heart.
"We have to see whether the human body accepts a foreign organ or not because sometimes it happens that the implanted organ works fine but it is the body that doesn't get along," Dr. Mohiuddin said.
"I know it's a shot in the dark, but it's my last choice," the heart patient said the day before the surgery.