MELD exceptions and new predictive score of death on long waiting lists for liver transplantation

Abstract

Background: Cirrhosis related complications, considered MELD exceptions, proved to add prognostic value to the MELD score in predicting waiting list mortality.

Aim: To identify the predictive value for death on a long waiting list (WL) for the complications of liver disease.

Methods: During 2004-2007, 372 consecutive adult patients were listed for liver transplantation (LT). To identify the potential predictors of patient death, univariate and multivariate Cox's proportional hazards regression model was used.

Results: In the univariate survival analysis the following variables were significant: spontaneous bacterial peritonitis, refractory ascites, hyponatremia, hepatic encephalopathy, hepatorenal syndrome, initial and current MELD score, initial and current Child-Pugh score. The independent predictors of death on our WL were: refractory ascites (p=0.002) and hepatorenal syndrome (p=0.002). Based on a logistic regression analysis a new score has been developed: Score = 1/(1+ exp(-(-4.38 + 1.34 x Refractory ascites + 0.9 x Hepatorenal syndrome + 0.15 x Current MELD). The c-statistic for the new score for prediction of death on the WL was 0.85 compared to 0.80 for current MELD score.

Conclusion: Refractory ascites and hepatorenal syndrome should add valuable points to the current MELD in order to better prioritize for LT patients included on long WL.

Abbreviations: Liver transplantation (LT), Model for End-Stage Liver Disease (MELD), waiting list (WL), United Network for Organ Sharing (UNOS), standard deviation (SD), receiver operating characteristic (ROC), hepatitis B virus (HBV), hepatocellular carcinoma (HCC), positive predictive value (PPV), negative predictive value (NPV), Child-Turcotte-Pugh (CTP), hepatic venous pressure gradient (HVPG).