A 57-year-old man receives a pig heart in a groundbreaking transplant to save him from heart disease

• For the first time, a man has received a heart from a genetically altered pig, The New York Times reported.
• The patient had a life-threatening heart condition that caused him to need a heart transplant.

For the first time, a man has received a heart from a genetically altered pig.

A 57-year-old man with a life-threatening heart condition has received a new heart from a genetically altered pig. It's the first successful transplant of a pig's heart into a human body, The New York Times reported Monday.

The operation took place in Baltimore at the University of Maryland Medical Center on Friday, The Times reported. Doctors at the medical center said the patient, David Bennett Sr. of Maryland, is doing well.

The experimental surgery was Bennett's last option for surviving heart disease. His son, David Bennett Jr., told USA Today that his father was mostly healthy until he started experiencing chest pains, fatigue, and shortness of breath in October.

After two months in the hospital, the elder Bennett had received several failed treatments and his condition was worsening. He was not a candidate for a human donor heart because he was too sick, doctors and family told The Times.

"It was either die or do this transplant. I want to live. I know it's a shot in the dark, but it's my last choice," Bennett said a day before the surgery, according to a statement provided by the University of Maryland School of Medicine.

More than 100,000 Americans are currently on organ transplant waitlists, and 17 people die every day because they cannot get the donor organs they need in time. The sickest patients, like Bennett, usually don't qualify for the waitlist at all.

The 8-hour procedure marks a major step in the effort to use genetically modified animal organs for life-saving transplants. Just a few months prior to Bennett's operation, doctors successfully attached a functional pig kidney to a deceased human patient on a ventilator.

Although it's too soon to call the pig-to-human heart transplant a success, the organ is working properly so far, Bennett's doctors said.

"It creates the pulse, it creates the pressure, it is his heart," Dr. Bartley Griffith, the director of the cardiac transplant program at the medical center, told The Times.

As of Monday afternoon, USA Today reported that Bennett has been breathing on his own without a ventilator. He still needs a machine to help circulate blood throughout his body, but his doctors will evenutally try to get his new heart pumping on its own.

"It's working and it looks normal," Griffith, who performed the operation, added. "We are thrilled, but we don't know what tomorrow will bring us. This has never been done before."

This success story likely instills hope in the thousands of others awaiting organ transplants, according to The Times.

This story is developing. Please check back for updates.