Association Between Trajectories of Estimated Plasma Volume Status and All-Cause Mortality in Severe Liver Cirrhosis Patients

BACKGROUND: The estimated plasma volume status (ePVS) has been identified as a potential prognostic marker for various critical illnesses. However, its prognostic value, especially regarding the assessment of ePVS changes over time in ICU patients with liver cirrhosis, remains uncertain. METHODS: This retrospective cohort study analyzed adult patients with liver cirrhosis in the MIMIC-IV database. We applied group-based trajectory modeling to identify distinct ePVS trajectories, selecting the optimal model based on the Bayesian information criterion (BIC), Akaike information criterion (AIC), average posterior probability (AvePP), and clinical interpretability. Kaplan-Meier survival curve was used to compare the mortality in cirrhosis patients with different ePVS trajectories. Hazard ratios (HRs) were calculated to elucidate the association between trajectories and prognosis in Cox proportional hazard models. Restricted cubic splines (RCS) were used to assess the relationship between ePVS and outcomes. RESULTS: A total of 2146 patients were included for analysis. GBTM identified 4 different ePVS trajectories: traj 1 (low-level slow increase), traj 2 (medium-level stable), traj 3 (ascend-descend at moderate high level), and traj 4 (high level down slightly). The Kaplan-Meier analysis showed that the mortality probability of traj 4 was the highest among the ePVS trajectories. After adjusting for demographic characteristics, clinical parameters, comorbidities, and treatment, compared with traj 1, traj 4 remained independently associated with an increased 28-day mortality rate (HR = 1.65, 95% CI: 1.15 - 2.38, P = 0.007). The RCS analysis showed a significant nonlinear association between ePVS and the risk of death. The subgroup analysis results were generally consistent, and no significant interaction was detected. CONCLUSIONS: Different ePVS trajectories are significantly associated with ICU mortality in patients with liver cirrhosis and may serve as powerful indicators for risk stratification and prognosis assessment in this population.