Association Between Liver Transplant Wait-list Mortality and Frailty Based on Body Mass Index

Area of Science:

• Transplant Surgery
• Gerontology
• Hepatology

Background:

• Obesity and frailty are linked to higher mortality in liver transplant candidates awaiting organs.
• Body mass index (BMI) alone may not accurately identify high-risk candidates due to ascites and muscle wasting.
• Frailty assessment is crucial for risk stratification in liver transplant candidates across all BMI categories.

Purpose of the Study:

• To determine if the association between frailty and wait-list mortality differs based on body mass index (BMI) in liver transplant candidates.
• To investigate the interaction between frailty and BMI in predicting mortality risk among individuals awaiting liver transplantation.

Main Methods:

• A prospective cohort study involving 1108 adult liver transplant candidates without hepatocellular carcinoma was conducted across 9 US centers.
• Frailty was assessed using the Liver Frailty Index (LFI) score (≥4.5), and candidates were categorized by BMI: nonobese (18.5-29.9), class 1 obesity (30.0-34.9), and class 2 or greater obesity (≥35.0).
• Competing risks regression was used to quantify wait-list mortality risk, adjusting for covariates and including an interaction term for frailty and BMI.

Main Results:

• Frail candidates, regardless of BMI, showed an increased risk of wait-list mortality compared to their non-frail counterparts.
• Frail nonobese and class 1 obese candidates had approximately 1.5 to 1.7 times higher mortality risk.
• Frail candidates with class 2 or greater obesity (BMI ≥35.0) faced a significantly higher mortality risk, over 3-fold greater than non-frail individuals in the same BMI category (adjusted subhazard ratio, 3.19).

Conclusions:

• Frailty is a significant predictor of wait-list mortality in liver transplant candidates, with the risk amplified in severely obese individuals (BMI ≥35.0).
• The Liver Frailty Index is a valuable tool for identifying high-risk candidates, especially those with higher BMIs where visual assessment of muscle mass may be unreliable.
• Integrating frailty assessment into pre-transplant evaluations can improve risk stratification and patient management for liver transplant candidates.