Science and Tech


Upcycled organs and pig hearts: where cardiac transplant is headed

According to Yale Medicine, about 3,500 people in the U.S. are waiting for a heart, and many will wait more than six months.
Posted at 12:36 PM, Feb 20, 2023

It’s been about a year since the world met David Bennett. Last year he seemed to be weakly singing the national anthem.  

At the time he was strongly recovering, 37 days into being the first person to have a xenotransplant. He was the first to get a genetically modified pig’s heart.  

The procedure was considered an early success with no rejection. He was sitting up, singing and watching the Super Bowl.  

But doctors were shocked and loved ones were saddened when things quickly turned. Bennett’s heart was swelling and failing. He died 60 days after the surgery.  

Doctor Bartley Griffith surgically transplanted the pig heart. 

"We spent the last full year trying to figure out what happened. And I'm not sure we're there yet. We did see an activation of a of a virus that's only a pig virus that didn't infect Dave, but it certainly seemed to infect his new heart," he said. 

He updated Scripps News on the progress since the experimental operation.  

Doctors have developed new, more sensitive tests after initial ones missed a virus in the donor pig heart.  

They’ve also learned more about the body’s immune response in Bennett’s case.   

"It gave us hope that with a little adjustment on the immune suppression, that maybe the less sick patient we might do better. And so that's what we're proposing right now," he said. 

That doesn’t mean a second transplant soon. Medical teams have to go through research, ethics committees and logistics. The biotech company behind the genetically modified hearts is building a facility hoping to meet FDA standards to make more quickly.  

U.S. Man Who Got 1st Pig Heart Transplant Dies After 2 Months

U.S. Man Who Got 1st Pig Heart Transplant Dies After 2 Months

A Maryland hospital says the first person to receive a heart transplant from a pig has died.


Scientists are also studying pig heart transplants in baboons to learn about how long immune-suppressing drugs would be needed to prevent longer-term rejection.  

And Dr. Griffith and the team will have to get the FDA’s OK to do another procedure. 

Meanwhile, popping up in hospitals across the country, a few dozen transplant teams are using another futuristic approach.  

One is nicknamed "heart in a box."  

Surgeons like Dr. Ben Bryner are implementing the device that’s using warmth instead of ice to keep a donor heart viable for longer.  

"It has a gas exchanger that does the work of the lungs. It has a pump that circulates blood through the heart. It has various ports where we can sample blood and give medications into the system. So it's all self-contained and portable, which is important, but it also builds on technology that we use every day," Bryner said. 

SCRIPPS NEWS' LINDSEY THEIS: Tell me about the significance of time, specifically in heart surgery.

BEN BRYNER: Time is always really important in any form of transplant and in heart transplant — it's even the most pressing. So we really only have four hours from the time we take the heart out of the donor to the time we restore blood flow to the heart in the recipient.  

Meaning before the heart in a box, doctors were stuck traveling no more than 90 minutes in each direction. This gets rid of that limitation. It’s also allowing more donor hearts. Before, hearts could only come from brain-dead patients whose hearts were still beating.  

In donors who were not brain-dead, doctors had to wait five minutes after the heart stopped, which is usually too long for it to be usable for transplant. 

While upcycled hearts and genetically altered pig organs might feel more like Frankenstein, the innovation could fill a growing need.  

Last year more than 5,000 patients were added to the heart transplant waiting list. Already in 2023, those numbers are up nearly 40%.