Patients with severe acute‐on‐chronic liver failure are disadvantaged by model for end‐stage liver disease‐based organ allocation policy

Summary Background Mortality for patients with acute‐on‐chronic liver failure (ACLF) may be underestimated by the model for end‐stage liver disease‐sodium (MELD‐Na) score. Aim To assess waitlist outcomes across varying grades of ACLF among a cohort of patients listed with a MELD‐Na score ≥35, and therefore having similar priority for liver transplantation. Methods We analysed the United Network for Organ Sharing (UNOS) database, years 2010‐2017. Waitlist outcomes were evaluated using Fine and Gray's competing risks regression. Results We identified 6342 candidates at listing with a MELD‐Na score ≥35, of whom 3122 had ACLF‐3. Extra‐hepatic organ failures were present primarily in patients with four to six organ failures. Competing risks regression revealed that candidates listed with ACLF‐3 had a significantly higher risk for 90‐day waitlist mortality (Sub‐hazard ratio (SHR) = 1.41; 95% confidence interval [CI] 1.12‐1.78) relative to patients with lower ACLF grades. Subgroup analysis of ACLF‐3 revealed that both the presence of three organ failures (SHR = 1.40, 95% CI 1.20‐1.63) or four to six organ failures at listing (SHR = 3.01; 95% CI 2.54‐3.58) was associated with increased waitlist mortality. Candidates with four to six organ failures also had the lowest likelihood of receiving liver transplantation (SHR = 0.61, 95% CI 0.54‐0.68). The Share 35 rule was associated with reduced 90‐day waitlist mortality among the full cohort of patients listed with ACLF‐3 and MELD‐Na score ≥35 (SHR = 0.59; 95% CI 0.49‐0.70). However, Share 35 rule implementation was not associated with reduced waitlist mortality among patients with four to six organ failures (SHR = 0.76; 95% CI 0.58‐1.02). Conclusions The MELD‐Na score disadvantages patients with ACLF‐3, both with and without extra‐hepatic organ failures. Incorporation of organ failures into allocation policy warrants further exploration.