Risk Index Predicts Pediatric Heart Allograft Non-Utilization.

BACKGROUND: Children listed for heart transplantation face the highest waitlist mortality among all solid organ transplant patients (14%). Attempts at decreasing donor allograft non-utilization (41.5%) could potentially decrease waitlist mortality for pediatric heart transplant patients. Our aim was to quantify the non-utilization risk of pediatric donor heart allografts at the time of initial offering. METHODS: Using the United Network of Organ Sharing (UNOS) database, we retrospectively analyzed 8823 deceased donors (≤18 years old) data through univariable and multivariable analysis and logistic regression models. These factors were divided into a training (n = 5882) and validation set (n = 2941). Donor clinical characteristics and laboratory values were used to predict non-utilization of donor hearts. The multivariable analysis used factors that were significant from the univariable analysis (p-value < .05), and the pediatric non-utilization risk index (pDRSI) included significant factors from the multivariable analysis, producing an overall risk score for non-utilization. With these data, we created a non-utilization risk index to predict likelihood of donor allograft non-utilization. RESULTS: From the 24 potential factors that were identified from univariable analysis, 17 were significant predictors (p < .05) of pediatric heart non-utilization in the multivariable analysis. Low left ventricular ejection fraction (odds ratio (OR)-35.3), hepatitis C positive donor (OR-23.3), high left ventricular ejection fraction (OR-3.29), and hepatitis B positive donor (OR-3.27) were the most significant risk factors. The phDSRI has a C-statistic of 0.80 for the training set and 0.80 for the validation set. CONCLUSION: Using over 8000 donors, the phDSRI uses 17 significant risk factors to predict risk of pediatric heart donor allograft non-utilization.

Constructing an Intent-to-Treat Score Index to Predict Survival Outcomes in Pediatric Liver Transplant Recipients.

BACKGROUND: Waitlist and posttransplant outcomes have been widely reported for pediatric liver transplantation. Yet, analyzing these metrics individually fails to provide a holistic perspective for patients and their families. Intent-to-treat (ITT) analysis fills this gap by studying the associations between waitlist outcomes, organ availability, and posttransplant outcomes. Our study aimed to construct a predictive index utilizing ITT analysis for pediatric liver transplant recipients (Pedi-ITT). METHODS: We performed a retrospective analysis utilizing de-identified data provided by the United Network for Organ Sharing (UNOS) from March 1, 2002, to December 31, 2021. We analyzed data for 12 926 pediatric recipients (age <18). We conducted a univariate and multivariable logistic regression to find the significant predictive factors affecting ITT survival. A scoring index was constructed to stratify outcome risk on the basis of the significant factors identified by regression analysis. RESULTS: Multivariable analysis found the following factors to be significantly associated with death on the waitlist or after transplant: gender, diagnosis, UNOS region, ascites, diabetes mellitus, age at the time of listing, serum sodium at the time of listing, total bilirubin at the time of listing, serum creatinine at the time of listing, INR at the time of listing, history of ventilator use, and history of re-transplantation. Using receiver operator characteristic analysis, the Pedi-ITT index had a c-statistic of 0.79 (95% confidence interval [CI]: 0.76-0.82). The c-statistics of the Model for End-Stage Liver Disease/Pediatric for End-Stage Liver Disease and pediatric version of the Survival Outcomes Following Liver Transplantation score indices were 0.74 (CI: 0.71-0.76) and 0.69 (CI: 0.66-0.72), respectively. CONCLUSIONS: The Pedi-ITT index provides an additional prognostic model with moderate predictive power to assess outcomes associated with pediatric liver transplantation. Further analysis should focus on increasing the predictive power of the index.

A modified Kidney Donor Risk Index for pediatric kidney transplant recipients.

BACKGROUND: The Kidney Donor Risk Index (KDRI) by Rao et al. was developed to measure the quality of kidney allografts. While Rao's KDRI has been found to be a robust measure of kidney allograft survival for adult kidney transplant recipients, many studies have indicated the need to create a distinct pediatric KDRI. METHODS: Our retrospective study utilized data from the United Network for Organ Sharing database. We examined 9295 deceased donor recipients' data for age < 18 years from 1990 to 2020. We performed a multivariate Cox regression to determine the significant recipient and transplant factors impacting pediatric kidney allograft survival. RESULTS: Multivariate analysis found 5 donor factors to be independently associated with graft failure or recipient death: age, female sex, anoxia as the cause of death, history of cigarette use, and cold ischemia time. Using receiver operator characteristic (ROC) curve analysis and analyzing the predictive value of each KDRI at 1, 5, and 10 years, the proposed pediatric KDRI had a statistically significant and higher predictive value for pediatric recipients at 5 (0.60 versus 0.57) and 10 years (0.61 versus 0.57) than the Rao KDRI. CONCLUSIONS: The proposed pediatric KDRI may provide a more accurate and simpler index to assess the quality of kidney allografts for pediatric recipients. However, due to the mild increase in predictive capabilities over the Rao index, the study serves as a proof of concept to develop a pediatric KDRI. Further studies should focus on increasing the index's predictive capabilities. A higher resolution version of the Graphical abstract is available as Supplementary information.

Disparate Intent-to-Treat Outcomes for Pediatric Liver Transplantation Based on Indication.

Background: The impact of indication for pediatric liver transplantation on waitlist and post-transplant mortality outcomes is well known, but the impact on intent-to-treat outcomes has not been investigated. Intent-to-treat survival analysis is important in this study because it is more comprehensive, combining the transplant outcomes of waitlist mortality, post-transplant mortality, and transplant rate into a single metric to elucidate any disparities in outcomes based on indication. Methods: Cox regression was used to analyze factors impacting survival in 8,002 children listed for liver transplant in the UNOS database between 2006 and 2016. The Kaplan-Meier method and log-rank test were used to assess differences in waitlist, post-transplant, and intent-to-treat mortality among the top 5 indications of biliary atresia, acute hepatic necrosis, metabolic disorders, hepatoblastoma, and autoimmune cirrhosis. Results: When compared to the reference group of biliary atresia, multivariate analyses showed that every indication was associated with inferior intent-to-treat outcomes except for metabolic disorders. Hepatoblastoma (hazard ratio (HR): 3.73), autoimmune cirrhosis (HR: 1.86), and AHN (HR: 1.77) were associated with significantly increased intent-to-treat mortality. Hepatoblastoma was also associated with increased post-transplant mortality (HR: 3.77) and was the only indication significantly associated with increased waitlist mortality (HR: 6.43). Conclusion: Significant disparity exists across all indications with respect to an increased intent-to-treat mortality, along with an increased post-transplant and waitlist mortality, when compared to the biliary atresia reference group. If further studies validate these findings, a reexamination of the equitable distribution of allografts for transplant may be warranted as well as a focus on disparities in survival after transplant.