The First Pig Heart Transplant Goes Wrong: Lets Dive In

Image Source: Fieldstadt, Elisha. “First Man to Receive a Transplanted Pig Heart Died of Heart Failure, Not Rejection, Encouraging Doctors.” NBCNews.com, NBCUniversal News Group, 7 July 2022, https://www.nbcnews.com/health/heart-health/first-man-receive-transplanted-pig-heart-died-heart-failure-not-reject-rcna37078.

Overview

On January 7th, 2022, Dr. Bartley Griffith - a cardiac surgeon at the University of Maryland, Baltimore - performed one of the most significant heart transplants in human history: he transplanted a pig heart into a human. David Bennett, 57, was the recipient of the organ. At first, the heart worked as intended and it seemed like the surgery was a success, however, 60 days later, he passed away. What's even more shocking is that doctors cannot decide on a specific cause of death. Griffith's report states that Bennett's capillaries - which deliver oxygen to the heart - failed and his cardiac muscle cells started to die. Griffith doesn't know exactly why this happened, however, there are possible explanations; let's explore.

Possible Explanations

One possible reason for the heart failure could be because of a weakened immune system. When transplanting organs from animals to humans or even among humans, the risk of organ rejection is real. Organ rejection is a phenomenon that occurs when the immune system rejects a transplanted organ and tries to destroy it because the immune system doesn't recognize it. To avoid this, doctors advise patients to take medications that weaken their immune system. Doctors, however, can only do this to a certain extent because, if a patient's immune system is too weak, they face other life threatening issues such as infections. Bennett was diagnosed with an infection known as pCMV, a virus found only in pigs. Although its symptoms are not severe, it can cause problems for those with a compromised immune system like Bennett.

Another possible reason for this could very well be organ rejection. Because this is a new development is the field of cardiology, doctors may not have given Bennett the proper amount of medication to suppress his immune system, thus, possibly leading to organ rejection. Finally, another explanation suggests that this may not have anything to do with the immune system. Bennett was in a very critical stage when he received the organ; he even needed Extracorporeal Membrane Oxygenation (ECMO) to allow his lungs and heart to properly function. He also had a history of internal bleeding and a blood infection. His heart may have failed because of his several underlying conditions. We don't know for sure if the heart failure happened due to one of these reasons, a combination of them, or none of them.

What Does The Future Hold For Such Transplants?

Doctors like Griffith are optimistic for the future because, although this particular transplant didn't go as planned, there is room for improvement. Griffith plans to continue administering such transplants on patients who have a reasonable chance at success, not like Bennett. Although FDA approval for these transplants may not happen any time soon, the possibilities for animal to human organ transplants are endless and need to be looked into more in-depth.