Should the routine use of the 6-minute walk test be implemented in liver disease assessment: Not so fast

Abstract

End-stage liver disease (ESLD) is a debilitating condition that often leads to death. Once diagnosed with ESLD, a patient’s quality of life decreases significantly. Well-established markers, such as the model for end-stage liver disease and Child-Pugh scores, are used to diagnose, monitor, and predict survival. Another tool, the 6-minute walk test (6MWT), has shown promise as an adjunct measure but remains underutilized despite its strong results and ease of reproducibility. Previous research has demonstrated that the 6MWT, as in many other conditions, helps predict survival, mortality, and outcomes in individuals with ESLD. A recent observational study by Corrêa et al found that the 6MWT is a reliable measure of functional capacity in patients with liver cirrhosis. Although the study’s small sample size of 20 patients limits its generalizability, the findings align with prior evidence showing that the 6MWT is an independent predictor of mortality and that poor test performance is associated with greater liver dysfunction. However, the 6MWT is a nonspecific test, and patient performance can be influenced by comorbidities such as heart failure, pulmonary disease, and frailty. Additionally, the optimal timing for administering the test has not been clearly established in the literature. Overall, although well-validated markers already exist for diagnosing and assessing outcomes in liver disease, the addition of the 6MWT-a low-cost, reliable, easily reproducible, and objective measure-may provide valuable prognostic and functional information if standardized protocols and covariates are better controlled.

Keywords: 6-minute walk test; Liver transplant; Liver failure; Cirrhosis; Functional capacity

Core Tip: The 6-minute walk test is a simple, low-cost, and reproducible assessment that has been shown to serve as a clinical predictor of survival, mortality, and other outcomes in individuals with end-stage liver disease. However, prior to its routine clinical implementation, additional research is needed to standardize testing protocols and to define the optimal timing for both administration and repeat assessment. Furthermore, the test should be interpreted as an adjunct measure of overall functional capacity and health status, rather than as a standalone indicator of hepatic function.