The utility of the ¹³C-methacetin breath test in predicting the long-term survival of patients with decompensated cirrhosis

Aim: The ¹³C-methacetin breath test (¹³C-MeBT) is a noninvasive tool that allows evaluation of the functional activity of the liver and the prediction of liver cirrhosis. Nevertheless, there is no information on its potential utility to predict long-term survival in patients with liver disease. Methods: Patients with cirrhosis were selected. All patients underwent a complete clinical assessment, standard biochemical tests, and ¹³C-MeBT at the beginning of the study. Death was recorded during the three years of follow-up. Survival curves were calculated by the Kaplan-Meier method, and Cox proportional risk models were used to identify predictive factors. The ability to classify the overall risk was assessed by the C statistic. Results: One hundred and twenty-three patients were included. A significant inverse correlation was found between delta over baseline at the 15 min point (DOB₁₅) after ingestion of ¹³C-methacetin and the Child-Pugh score (r = -0.411, p < 0.001). In multivariate analysis, DOB₁₅ ≤ 4.5‰ was associated with mortality, [HR = 2.58 95% CI (1.17-5.69)]. In conclusion, our results confirm the utility of ¹³C-MeBT as a simple, noninvasive tool to quantitatively assess the liver's functional reserve and as a potential predictor of long-term survival in patients with decompensated cirrhosis.