Should All Status 1A Patients Be Prioritized Over High MELD Patients? Concept of Risk Stratification in Extremely Ill Liver Transplant Recipients

Abstract

Status 1A patients are prioritized over liver disease patients regardless of Model for End-stage Liver Disease (MELD) score. We aimed to identify groups with high waitlist mortality in Status 1A and MELD ≥40 patients to determine who would most benefit from transplantation. Data on patients listed as Status 1A (n = 4447) and MELD ≥40 (n = 3663) over 15 years (2002-2017) was obtained from United Network for Organ Sharing/Organ Procurement and Transplant Network registry. They were divided into 2-derivation and validation groups. Risk factors associated with 28-day waitlist mortality were identified in derivation group and provided risk scores to divide patients into risk groups. Score system was applied to validation group to check its applicability. Risk factors for waitlist mortality in Status 1A included life support, performance status, severe coagulopathy, severe hypo or hypernatremia, and grade 3-4 encephalopathy. Risk factors in MELD ≥40 included higher MELD scores (≥45), age, sex, race, life support, and encephalopathy. On comparing 7- and 28-day mortality, both were higher in Status 1A and MELD ≥40 high-risk groups compared with low-risk groups in the derivation group (P < 0.001). Probability of transplantation was lowest for high-risk MELD ≥40 patients compared with all other groups (P < 0.001). These findings were reproduced in the validation set. Our proposed risk stratification system also showed acceptable 1-year graft and patient survival in high-risk groups. Our risk scoring system for extremely ill liver transplant candidates successfully stratified risk of waitlist mortality. Waitlist outcomes might be improved by modifications involving categorization of patients based on the presence/absence of risk factors.