Plasma copeptin concentration is a predictor of tolvaptan efficacy in patients with hepatic ascites

Aims:No solid evidence-based opinion was raised regarding predictors of the degree of ascites reduction with tolvaptan.This retrospective cohort study aimed to examine whether serum copeptin concentration is a useful predictor of this. Methods:The study population consisted of 80 patients with liver cirrhosis treated with tolvaptan for hepatic ascites effusions at Nara Medical University Hospital from May 2014 to December 2018.Forty-three patients who lost＞1.5 kg of body weight in the first week after starting tolvaptan were classified as good responders and the remaining 37 as poor responders.Various laboratory parameters were measured immediately before the start of tolvaptan therapy to examine factors associated with predicting its efficacy. Results:In the univariate analysis,no significant differences with respect to age(67.6 vs.69.8 years,p＞0.05),sex,body mass index(24.8 vs.23.7 kg/m2,p＞0.05),Child-Pugh score(9.4 vs.9.7,p＞0.05),and Model for End-stage Liver Disease score(11 vs.12,p＞0.05)were found between the two groups.Conversely,aspartate transferase and alanine transaminase(ALT)levels were significantly lower in the good response group(52.9±56.3 vs.68.8±50.7 U/L,p＜0.05;26.2±30.6 vs.40.5±33.5 U/L,p＜0.01),whereas serum copeptin and serum sodium concentrations were significantly higher(57.1±15.0 vs.45.8±16.0 pg/mL,p＜0.01;136.3±3.4 vs.133.8±5.8 mEq/L,p＜0.05).In the multivariate analysis,serum copeptin concentration and ALT were statistically significant factors(p＜0.01,p＜0.05).Regression analysis of the association between the tolvaptan efficacy for refractory ascites and pretreatment serum copeptin concentration showed that a copeptin concentration cutoff of 45.9 pg/mL could predict treatment efficacy with a sensitivity,specificity,and area under the curve of 76.7％,59.5％,and 0.71％,respectively. Conclusion:Serum copeptin concentration may be a predictor of tolvaptan efficacy for refractory ascites effusion in Japanese patients with liver cirrhosis.