Abstract
The post-transplant outcomes of patients with Model for End-stage Liver Disease (MELD) score primarily driven by renal dysfunction are poorly understood. This was a retrospective cohort study of liver transplant (LT) alone recipients between 2005 and 2017 using the United Network for Organ Sharing (UNOS) database. The proportion of MELD Sodium score attributable to creatinine ("KidneyMELD") was calculated: (9.57 × ln (creatinine) × 100)/(MELD-Na - 6.43). The association of KidneyMELD with (a) all-cause mortality and (b) estimated glomerular filtration rate ≤30 mL/min/1.73(2) at 1-year post-LT were evaluated. Recipients with KidneyMELD ≥50% had a 52% higher risk of post-LT mortality (adjusted hazard ratio 1.52 vs KidneyMELD 0%, 95% CI: 1.36-1.69; P < .001). This risk was significantly greater for older patients, particularly when >50 years at LT (interaction P < .001). KidneyMELD ≥50% was also associated with an 11-fold increase in the odds of advanced renal dysfunction at 1-year post-LT (adjusted odds ratio 11.53 vs KidneyMELD 0%; 95% CI 8.9-14.93; P < .001). Recipients prioritized for LT primarily on the basis of renal dysfunction have marked post-LT mortality and morbidity independent of MELD Sodium score. The implications of these results in the context of the new UNOS "safety net" kidney transplant policy require further study.