After 15 years of covering new cardiovascular technologies, it’s not often that something lands on my email, or that I see at a conference, it’s something really new, innovative and has the potential to be an immediate paradigm shift in the way medicine is practiced. However, I found myself abandoning what I was doing to immediately start working on a story and video about the first pig heart transplant in a human when news broke on the night of January 10. This first-in-man procedure certainly caught my eye. and imagination, as he did with cardiologists and the general public.
The University of Maryland Medical Center (UMMC) has created a cardiac xenotransplantation program (transplantation of animal organs) a few years ago with the aim of developing a technology for the transplantation of pig hearts into humans. They were the first to do so successfully on January 7, 2022 in David Bennett, a 57-year-old advanced heart failure patient from Maryland. He had previously been turned down for a heart transplant by other centers and was only able to survive ECMO in the hospital. UMMC asked the FDA to clear the breakthrough procedure for compassionate use because no other options remained for this patient. The FDA granted clearance on New Year’s Eve.
If this procedure is successful, it could truly be a paradigm shift in how patients with stage IV heart failure are treated in the future. This could eliminate the heart transplant waiting list for human hearts with the possibility of having a heart immediately available for surgery. It can also make hearts available regardless of patient comorbidities or other factors that might otherwise disqualify a patient today for human heart transplantation. This concept of using pig hearts could also eliminate the need for bridge-transplant technologies such as left ventricular assist devices (LVADs). These devices are also used for destination therapy, and pig hearts may offer a more attractive alternative. Additionally, while new technologies in development for total artificial hearts show promise, the use of pig hearts could eliminate many of the problems associated with using a completely man-made device, such as the thrombosis, haemolysis, risk of driveline infection and the need for an external power supply.
The porcine heart is very similar in size, shape and function to the human heart. So much so that pigs are used in preclinical research for cardiovascular devices before they are used in human patients. Pig hearts are also used as substitutes for human hearts due to their high similarity in anatomy classes and medical schools.
However, pig genetics are different from human genetics, so it’s not as simple as removing a pig’s heart and placing it into a human. The UMMC xenotransplantation used a genetically modified porcine heart. They modified 10 genes in the heart to try to eliminate the common problem of rejection by the patient’s body, which is a problem in both human heart transplants and previously attempted animal heart transplants. Another gene they modified regulates the growth of pig organs.
Only time will tell with this first patient if gene-editing technology succeeds and makes xenotransplantation possible. The longer Mr. Bennett survives, the further we move forward in our understanding of this technology and its viability.
When I first started covering cardiology, many cardiologists I spoke with at cardiology meetings like ACC and TCT thought that the new concept of transcatheter heart valve replacement discussed in news sessions technologies was a science fiction project and would never be widely used, even if it worked. . But, in less than a decade, transcatheter aortic valve replacement (TAVR) has become the dominant volume form of aortic valve replacement procedure in the United States. The concept of pig heart transplants could be the same type of paradigm shift, and one worth watching closely, now that it has suddenly exploded into the limelight.
Read more: First human receives pig heart transplant
VIDEO: Details on the first human heart transplant surgery in a pig