Cystatin C and Sarcopenia Predict Acute on Chronic Liver Failure Development and Mortality in Patients on the Liver Transplant Waiting List.

BACKGROUND: Cystatin C (CysC) is an early biomarker of renal dysfunction scarcely studied in patients awaiting liver transplantation (LT). Sarcopenia is frequent in cirrhosis and impacts prognosis. We aimed to assess the capability of these factors to predict survival and acute-on-chronic liver failure (ACLF) in patients awaiting LT, as well as early post-LT outcomes. METHODS: Single-center study that included all cirrhotic patients listed for LT between 2014 and 2017. Competing risk regression analysis was used to evaluate the capability of liver-, kidney- and global status-related variables at waitlist (WL) inclusion to predict WL mortality and ACLF. Variables associated with post-LT outcomes were evaluated with logistic regression analysis. RESULTS: One-hundred-and-eighty patients were included. Fifty-six (31%) patients developed ACLF, 54 (30%) underwent LT and 35 (19%) died. In the adjusted competing risk regression analysis, CysC >/=1.5 mg/L, sarcopenia and MELD-Na were independent predictors of ACLF in the WL, while CysC >/=1.5 mg/L, sarcopenia and albumin were independent predictors of mortality. The cumulative incidence of ACLF and mortality at 12 months were 50% and 34% in patients with sarcopenia and CysC >/=1.5 mg/L. An eGFR by CKD-EPI-CysC-Creatinine <60 ml/min/1.73 m at WL inclusion was an independent predictor of the need for RRT in the first month post-LT. CONCLUSIONS: Higher levels of CysC and sarcopenia are strongly associated with the ACLF and mortality in WL. The assessment of both risk factors may improve the prognostic evaluation and allow identifying a group of patients with a very high risk of poor outcomes while awaiting LT.