Pediatric donor heart allocation in the United States, 2006-2017: Current patterns and potential for improvement.

Objective: To understand current donor heart allocation practices for pediatric transplantation.

Background: Despite high waitlist mortality rates among pediatric patients awaiting transplant, a substantial proportion of donor hearts go unused. Analysis of UNOS match run data may identify opportunities to optimize organ utilization.

Methods: Using UNOS/OPTN data, we evaluated all match runs for pediatric (<18 years) donor hearts from 1/1/2006 to 3/31/2017. We assessed final disposition of donor hearts, reasons for donor refusal, and other match run characteristics. Variation in total offers made per organ, and refusal rates by OPOs were also evaluated.

Results: Of 7585 pediatric potential donor hearts, 2226 (29.3%) were refused. Hearts accepted underwent a median of 2 offers (IQR: 1-5), compared to 11 (IQR: 5-24) for refused donor hearts. Organ refusal rates decreased from 36.9% in 2006-2009 to 22.3% in 2014-2017 (P < .001). Reasons for refusal included quality (80.9%), size mismatch (57.5%), and known/suspected crossmatch positivity (39.1%). Among 1800 hearts deemed "poor quality" by ≥1 transplant program, less than half (46.6%) were coded "poor quality" by multiple refusing programs. Organ refusal rates ranged from 13.5% to 83.3% across OPOs, and there was no correlation between refusal rates and median number of offers made by the OPO.

Conclusion: Although more organs are being used over time, 1 in 5 available pediatric donor hearts are still discarded. The lack of donor evaluation consensus and wide variability in donor refusal rates indicates a need for standardization of donor assessment and match run processes across OPOs.