Determining Factors of Heart Quality and Donor Acceptance in Pediatric Heart Transplants

Abstract

There is substantial need to increase donor heart utilization in pediatric heart transplantation. Almost half of pediatric heart donors are discarded, despite nearly 20% waitlist mortality. Physicians have limited time to view heart condition data and decide to accept the donor heart once the heart becomes available. Due to the large amount of data associated with each donor heart and the lack of data-driven guidelines, physicians often do not have adequate metrics to determine acceptable heart quality. This research characterizes the differences in the clinical course between accepted and rejected pediatric donor hearts. A longitudinal study assessing the effect of static and dynamic measurements on the donor heart’s function from the time of declaration of brain death to either disposal or heart procurement is developed by analyzing donor data via DonorNet, the system used by the United Network for Organ Sharing (UNOS) to match donors to a ranked order of recipients based on blood type, heart size, urgency status of the recipient, and other factors. Cardiovascular milieu (i.e. blood pressure, heart rate, medical management) and surrogate markers of organ perfusion, such as kidney and liver function, also inform our analyses and determine whether there are direct or indirect associations between these myriad markers and heart function. It also analyzes the proportion of measurements in stable and acceptable ranges over time, as well as typical minimum, maximum, and final measurements for different functions. All analyses are compared between accepted and rejected hearts using logistic regression and statistical analysis. Using the most recent measurements for each donor at 24 hours after brain death, the analysis identified significant factors in predicting donor heart acceptance: Left Ventricular Valve Dysfunction, Age, Shortening Fraction, and 4 Chamber Ejection Fraction. Additionally, visual tools were created as deliverables to aid physicians to decrease decision time and increase confidence in donor heart acceptance or rejection.