Aim: To evaluate the prognostic value of percentage of (13)C-phenylalanine oxidation ((13)C-PheOx) obtained by (13)C-phenylalanine breath test ((13)C-PheBT) on the survival of patients with chronic liver failure.
Methods: The hepatic function was determined by standard liver blood tests and the percentage of (13)C-PheOx in 118 chronic liver failure patients. The follow-up period was of 64 mo. Survival analysis was performed by the Kaplan-Meier method and variables that were significant (P < 0.10) in univariate analysis and subsequently introduced in a multivariate analysis according to the hazard model proposed by Cox.
Results: Forty-one patients died due to progressive liver failure during the follow-up period. The probability of survival at 12, 24, 36, 48 and 64 mo was 0.88, 0.78, 0.66, 0.57 and 0.19, respectively. Multivariate analysis demonstrated that Child-Pugh classes, age, creatinine and the percentage of (13)C-PheOx (HR 0.338, 95% CI: 0.150-0.762, P = 0.009) were independent predictors of survival. When Child-Pugh classes were replaced by all the parameters of the score, only albumin, bilirubin, creatinine, age and the percentage of (13)C-PheOx (HR 0.449, 95% CI: 0.206-0.979, P = 0.034) were found to be independent predictors of survival.
Conclusion: Percentage of (13)C-PheOx obtained by (13)C-PheBT is a strong predictor of survival in patients with chronic liver disease.