What is the role of MELD (Model for End-Stage Liver Disease) scoring in determining the urgency of liver transplantation for patients with end-stage liver disease?

From the Guidelines

The MELD score is the primary tool used to prioritize patients for liver transplantation based on their risk of mortality from end-stage liver disease, with a recommended listing threshold of MELD score > 15 1. This numerical scoring system ranges from 6 to 40, with higher scores indicating greater urgency and mortality risk. The MELD calculation incorporates three laboratory values: serum bilirubin, serum creatinine, and international normalized ratio (INR) for prothrombin time, providing a reliable assessment of disease severity. Some key points to consider when using the MELD score include:

• Patients with higher MELD scores are placed higher on the transplant waiting list, ensuring that donor organs go to those with the greatest medical need and shortest expected survival without transplantation 1.
• The MELD system has significantly improved allocation fairness by replacing subjective assessments with objective criteria.
• For certain conditions like hepatocellular carcinoma, exception points may be added to the calculated MELD score to account for mortality risks not captured by the standard formula 1.
• The score is recalculated periodically for waitlisted patients to ensure their priority status remains current as their condition changes.
• A holistic review of the patient, including age, frailty, and comorbidities, should be used in conjunction with the MELD score to determine priority for transplantation 1.
• There are several exceptions to MELD, including pulmonary complications of cirrhosis, hepatic encephalopathy, and primary hyperoxaluria, which may require extra points to be attributed to patients to give them priority to transplantation 1.

From the Research

MELD Scoring Overview

• The Model for End-Stage Liver Disease (MELD) score is a numerical scale used to estimate the severity of liver disease in patients [2].
• It incorporates serum bilirubin, creatinine, and the international normalized ratio (INR) into a formula to predict 90-day mortality in patients with cirrhosis [2].

Role in Liver Transplantation

• The MELD score is currently utilized in the United States to prioritize deceased donor organ allocation for patients listed for liver transplantation [2].
• It has been shown to be superior to other prognostic models, such as the Child-Turcotte-Pugh score, in predicting mortality in patients with end-stage liver disease [2].
• The implementation of the MELD score has led to a reduction in waitlist mortality and an increase in the number of deceased-donor transplants without adversely affecting long-term outcomes after liver transplantation [3, 4].

Limitations and Variations

• The MELD score has limitations, such as inter-laboratory variability of the parameters included in the score, and the inability to predict mortality accurately in specific settings [3].
• Variations of the original MELD score, such as the addition of serum sodium or looking at the change in MELD over time, have been examined to improve its accuracy [2].
• The inclusion of hepatic encephalopathy (HE) severity in MELD has been shown to improve the prediction of 90-day wait-list survival [5].

Predictive Value

• The MELD score has been shown to be a good predictor of mortality among patients with decompensated liver cirrhosis over a 1-month period [6].
• It has a sensitivity of 72.2% and a positive predictive value of 93.6% with an area under the curve of 0.926 for all-cause mortality among decompensated liver cirrhosis patients [6].
• Multiple logistic regression analysis has identified MELD scores as an independent predictor of mortality in patients with decompensated liver cirrhosis [6].