Why Research is the Key to Improving Pediatric Heart Transplants Rates

August 28, 2021 by hh5ax@virginia.edu

Q. Tell me about your project.
A. In pediatrics, about 20% of kids waiting on the heart transplant list will die before they receive a transplant. There are a number of reasons for this statistic, but one of the biggest is that there are not great ways to support these patients while they are waiting for a transplant. For adult patients, there are VAD (ventricular assist device) machines that can support a heart until they receive a transplant.

The bigger issue is that we don’t really know what makes for a good donor heart. If you think about how a patient becomes a donor, it’s typically following a catastrophic event such as a terrible car accident, an illness, a stroke, or child abuse. There is a lot of stress and strain placed on that heart, including CPR, as well as the stress caused by the brain in these situations. When someone like me is then trying to determine whether to accept one of these donor hearts, one of the biggest challenges is determining whether that heart has been permanently damaged or hasn’t fully had time to recover; if I choose wrong, I can make my patient worse.

Equally alarming is that approximately 50% of available donor hearts are discarded and never used. So, think about that: 20% of patients are dying, while 50% of hearts are not accepted, these numbers don’t make sense. Further, unlike adult hearts, pediatric hearts are incredibly resilient as they haven’t been subjected to decades of disease and abuse. Pediatric hearts routinely demonstrate complete recovery, even after periods of significant insult and dysfunction as are seen after brainstem herniation, CPR, accidents, etc. However, nobody has ever evaluated the ‘natural course’ of a pediatric heart after declaration of brain death and how this affects the short and mid-term outcomes of children who are transplanted with these hearts.

In an attempt to improve donor utilization, we are now looking at the last 10 years of pediatric UNOS data (United Network of Organ Sharing, the agency that oversees all donors and recipients) data. First, we want to characterize the typical course of what a heart is exposed to and how it changes during a donor’s ‘terminal hospitalization’ and help predict the likelihood of functional recovery in those hearts that may be demonstrating dysfunction at any given point in time.  We are also looking at treatments used to support and resuscitate these donor organs and determine what treatments result in a better outcome instead of causing more harm. From there, we’ll look at what hospitals are doing with respect to organ selection practices and use this information to help determine how they affect heart transplant recipient outcomes, as measured by 30 day and 1 year post transplant survival.

Our ultimate goal is to make a predictive model that can help inform these complicated decisions for pediatric heart transplant doctors trying to choose the correct heart, at the correct time, for their specific patient. Moving forward, the next time it’s 3:00 in the morning and I’m looking at 40 different factors trying to determine if the heart currently available to me is one I should accept, I would like to have this model help me make an informed decision that is best for my patient.

Q. How long have you been working on this project?
A. I started researching pediatric donor heart utilization approximately 4 years ago. I was part of an international survey looking at different practitioners’ donor acceptance practices and when we learned more about what others were doing and how much those practices varied across institutions, I thought, “Are we that much all over the map?” I then had the opportunity to be one of 7 task force chairs reviewing the available scientific literature on the topic of pediatric donor heart utilization and management which resulted in a consensus statement for the International Society of Heart and Lung Transplantation. At the end of it all, we realized there was still so much we didn’t know about this topic.

Q. Why is this so important to you?
A. This work is important in so many ways. I believe that trying to improve the 20% waitlist mortality and 50% refusal rate stats is low hanging fruit. Even if we make a small improvement, that would be huge for patient care.

In addition to improving recipient outcomes, this research is important because the parents and caretakers of these patients who have become donors are making an incredible sacrifice to give their children’s organs to save a life. These heart-wrenching decisions are oftentimes the only positive to come out of the worst thing to ever happen in their lives. After going through that struggle to find out their child’s organs weren’t used is heartbreaking. To help that not happen would mean a lot.

Q. What would you want everyone to know?
A. The infrastructure and opportunities to do research at UVA are much larger than anyone realizes. For this project, through just a few emails, I was able to recruit two experienced PhD’s from the Schools of Engineering and Data Science who then were able to find 5 4th year students who made this their capstone project. Further, we were readily able to recruit 22 other undergrads who helped me manually extract data from the charts of 9,000 donors in just 6 months! Further, to help ensure the time of my PhD partners and the efforts of a PhD candidate, we were able to find and successfully compete for two pilot grants offered through UVA and are in the process of competing for longer term, federal level funding. It would not have been possible without the help from so many different individuals. Every roadblock I’ve faced has very rapidly been resolved by reaching out for help from people at UVA.

Q. How do you recommend fitting research into your day as a busy clinician?
A. It takes time. You have to want to ask the questions and you have to put in the time to figure out how it will work. It’s a lot of nights and weekends when you have a busy clinical schedule. My biggest piece of advice is to ask around and find people who are interested in doing research. We are currently in the process of putting together a research group with the NICU, PICU, and Cardiology and plan to meet on a regular basis to talk about research projects of interest.

There are tons of unanswered questions that have never been researched. We work at an academic institution and we make our fields and our patient populations better. You can’t do any of these things on your own. Find the help, it’s out there.

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