Model for end-stage liver disease excluding international normalized ratio (MELD-XI) score predicts heart transplant outcomes: Evidence from the registry of the United Network for Organ Sharing

Abstract

Background: Hepato-renal function is a valuable predictor of success after left ventricular assist device therapy and heart transplantation. Hence, we analyzed the importance of the Model for End-stage Liver Disease excluding international normalized ratio (MELD-XI) score to outcomes after heart transplant.

Methods: Adults undergoing heart transplant from the United Network for Organ Sharing (UNOS) database were identified (1994 to 2014). Individual MELD-XI scores were calculated; patients were stratified by MELD-XI quartiles (Q1 to Q4). Multivariate logistic regression and the Cox proportional hazard model were implemented to determine any association between MELD-XI scores, survival and other outcomes.

Results: From 39,711 patients undergoing OHT during the study period, MELD-XI score [median 10.7 (interquartile range 7.0 to 14.4)] was calculated for 36,005 patients (76% male and 75% white, 34% Status 1A). Higher MELD-XI scores had higher rates of pre-transplant extracorporeal membrane oxygenation, intra-aortic balloon pump, inotrope use and mechanical ventilation (p < 0.001 for all). Adjusted long-term mortality (median follow-up 8.1 years) was associated with MELD-XI score (hazard ratio [HR] 1.021 [1.016 to 1.026], p < 0.001). The highest MELD-XI quartile was associated with an HR 1.364 [1.255 to 1.482] risk of mortality compared with Q1. MELD-XI score was also associated with increased post-transplant infections (adjusted HR Q4 vs Q1: 1.364 [1.153 to 1.614], p < 0.001), stroke (adjusted HR Q4 vs Q1: 1.410 [1.074 to 1.852], p = 0.013), dialysis (adjusted HR Q4 vs Q1: 3.982 [3.386 to 4.683], p < 0.001), rejection (adjusted HR Q4 vs Q1: 1.519 [1.286 to 1.795], p = 0.003) and prolonged hospitalization (adjusted HR Q4 vs Q1: 1.635 [1.429 to 1.871], p < 0.001).

Conclusion: Hepato-renal dysfunction, measured with MELD-XI score, predicts morbidity and mortality in patients undergoing orthotopic heart transplantation. Etiology of hepato-renal dysfunction should be sought and treated before heart transplantation.

Keywords: MELD-XI; congestive heart failure; heart transplant; hepatic dysfunction; hepato-renal failure; left ventricular assist device.