Saving babies: Q&A with a world-renowned pediatric cardiologist

Dr. David Kalfa is pioneering new frontiers in pediatric surgery. In 2023, he performed the world's first "domino" infant heart transplant, a groundbreaking procedure during which a donated heart saves one infant, and the valves from the recipient's diseased heart are then used to save another. 

Newly arrived in South Florida in September, Kalfa is the chief of cardiovascular surgery at Nicklaus Children’s Hospital and a co-director of the Nicklaus Children's Heart Institute. At the Herbert Wertheim College of Medicine, he serves as a professor in the departments of pediatrics and surgical sciences as well as a researcher focused on transplant innovation, surgical planning and robot surgery.

Among his plans: to develop a congenital heart defect research institute that builds upon the collaboration between Nicklaus and FIU to integrate basic science, translational research and clinical trials.

Kalfa recently discussed his professional interests and the exciting work he is trailblazing.

Congenital heart defects are the most common birth defects, affecting nearly 1% of newborns in the U.S., or about 40,000 infants. Half of those will need an operation to fix or replace a valve. What unmet clinical needs in this area does your research address?

We still don’t have many good options in terms of heart valve replacement for children. Today, we can use preserved, non-living tissue valves that from animals. But these do not last long. They degenerate and stop working. Another challenge is that, sometimes, there’s no valve small enough. The smallest valve we have at our disposal is 15 millimeters. Sometimes the place we need to put the valve is 6 or 7 mm. Lastly, those replacement valves can’t grow with the baby or child. They outgrow the valve, and each time we need to replace it involves another open heart surgery.

I’m focused on living allogenic valve transplantation [LAVT, also known as partial heart transplantation]. We’re working on a framework for storing and rehabilitating living donor valves, capable of growing with the child, so there’s no need for repeated surgeries.

How would these living valves be kept ‘alive’ before they could be used?

For mid-term and long-term storage, my lab developed a bioreactor to keep fresh, living valves. This device is designed to provide a mechanical environment to keep the valve opening and closing, like it would in the body. The tissue would also be kept in a specific solution that my lab has patented. It can keep tissue alive for seven weeks, which is huge because in the past, before we came up with this technology, we could only keep a valve alive outside the body for a maximum of 48 hours. Recently, I received a $4.2 million NIH grant to continue fine tuning this bioreactor and begin pre-clinical trials.

So, with partial heart transplants, patients wouldn’t need to wait for a donor?

Exactly. The idea is they would be available essentially ‘off-the-shelf’ for children in need. This research can have a major impact on patients because it increases the availability of these valves and the chance of having the right valve for the right patient at the right time.

Partial heart transplants are still relatively rare. However, you have performed quite a few of these surgeries, correct?

Yes, I performed the first domino, or sequential, infant partial heart transplant when I was working at NewYork -Presbyterian Hospital - Columbia University. Today, the kids are doing fantastically well. 

I also did what we call a split-root domino partial heart transplant. First, a patient received a donor heart. Then, two valves from that patient’s heart were removed and given to two other children with heart conditions. It was unbelievable. You do a heart transplant to save the life of one child and then, using their old heart, you save two more children. All of this happened within 24 hours of non-stop surgery. It was pretty intense, I have to say. I was pretty emotional about it at times. That is a major case that will stay with me for the rest of my life.

Do you work in robotic surgery?

I launched a formal pediatric cardiac robotic program at Columbia University, the first of its kind of program in the country. So, I have plans to do the same thing here at FIU in collaboration with other surgeons. The beauty of robotic surgery is it’s the least invasive type of surgery you can do. The cosmetic and psychological impact for children is huge because you can avoid the big scar down the front of their chest. There are actually some studies that show the psychological benefit of avoiding that sort of scar.

Do you have plans to use AI in your research or practice?

I think there’s huge opportunities to use AI to improve outcomes and quality of life for children with congenital heart defects. One of the projects that I am, working on is using AI to try to predict adverse events and cardiac arrests in the ICU and also using AI for risk assessment of patients with borderline left ventricle who need open heart surgery.

What does it feel like to be a part of something like this?

This is definitely a kind of new frontier and that’s exciting. It’s the very reason I chose to become a pediatric cardiac surgeon and scientist, an "MD Ph.D." I wanted to develop innovations that can help improve outcomes for children with congenital heart disease. I think the work we’re doing can really be a gamechanger and transform lives in South Florida, across the country and the world.