Effects of Allocating Livers for Transplantation Based on Model for End-Stage Liver Disease-Sodium Scores on Patient Outcomes
Nagai S, Chau LC, Schilke RE, Safwan M, Rizzari M, Collins K, Yoshida A, Abouljoud MS, and Moonka D. Effects of allocating livers for transplantation based on model for end-stage liver disease-sodium scores on patient outcomes. Gastroenterology 2018;155(5):1451-1462.e3.
BACKGROUND & AIMS: The Model for End-stage Liver Disease and Sodium (MELD-Na) score was introduced for liver allocation in January 2016. We evaluated the effects of liver allocation, based on MELD-Na score, on waitlist and post-transplantation outcomes.
METHODS: We examined 2 patient groups from the United Network for Organ Sharing registry; the MELD-period group was composed of patients who were registered as transplant candidates from June 18, 2013 through January 10, 2016 (n = 18,850) and the MELD-Na period group was composed of patients who were registered from January 11, 2016 through September 30, 2017 (n = 14,512). We compared waitlist and post-transplantation outcomes and association with serum sodium concentrations between groups.
RESULTS: Mortality within 90 days on the liver waitlist decreased (hazard ratio [HR] 0.738, P < .001) and transplantation probability increased significantly (HR 1.217, P < .001) in the MELD-Na period. Although mild, moderate, and severe hyponatremia (130-134, 125-129, and <125 mmol/L) were independent risk factors for waitlist mortality in the MELD period (HR 1.354, 1.762, and 2.656; P < .001, P < .001, and P < .001, respectively) compared with the reference standard (135-145 mmol/L), these adverse outcomes were decreased in the MELD-Na period (HR 1.092, 1.271 and 1.374; P = .27, P = .018, and P = .037, respectively). The adjusted survival benefit of transplant recipients vs patients placed on the waitlist in the same score categories was definitive for patients with MELD-Na scores of 21-23 in the MELD-Na era (HR 0.336, P < .001) compared with MELD scores of 15-17 in the MELD era (HR 0.365, P < .001).
CONCLUSIONS: Liver allocation based on MELD-Na score successfully improved waitlist outcomes and provided significant benefit to hyponatremic patients. Given the discrepancy in transplantation survival benefit, the current rules for liver allocation might require revision.
Medical Subject Headings
End Stage Liver Disease; Female; Hepatitis C; Humans; Liver Transplantation; Male; Middle Aged; Sodium; Tissue and Organ Procurement; Waiting Lists