Association between albumin-bilirubin (ALBI) score and all-cause mortality in critically ill patients with pulmonary embolism: a cohort study based on the MIMIC-IV database.

BACKGROUND

The albumin-bilirubin (ALBI) score is a readily available objective indicator, and its prognostic value extends beyond liver diseases. Among individuals with pulmonary embolism (PE), fluctuations in ALBI may reflect liver congestion and hypoperfusion caused by right heart failure. Nevertheless, the association between ALBI score and mortality in critically ill patients with PE remains underexplored. This research sought to explore the association between the ALBI score and all-cause mortality (ACM) in populations with PE.

METHODS

Based on the Medical Information Mart for Intensive Care IV (MIMIC-IV) database, this retrospective observational study included 780 critically ill patients with PE. The primary outcome was ACM within 30 days. Secondary outcomes included ACM within 90 and 365 days. Kaplan-Meier (K-M) curves and log-rank tests were used to estimate survival differences. Multivariable Cox proportional hazards models and restricted cubic splines (RCS) were used to investigate associations between ALBI and ACM. Subgroup analysis was conducted to validate the robustness of these results.

RESULTS

The median age of the study population was 63.76 years. Among the population, males accounted for 54.49%. K-M analysis demonstrated significant survival differences across the ALBI quartiles (log-rank P<0.001). Multivariable Cox regression demonstrated that each 1-unit elevation in ALBI was associated with a 31.7% increased risk of ACM within 30 days [hazard ratio (HR) =1.317, 95% confidence interval (CI): 1.185-1.464, P<0.001]. Using the Q1 group of the ALBI quartile as the baseline, the Q4 group exhibited a significantly elevated risk ratio. The ACM within 30 days in the Q4 group was 2.043 times higher compared to the Q1 group (HR =2.043, 95% CI: 1.231-3.392, P=0.006). RCS analysis indicated a linear positive association between ALBI and mortality at each time point (P for nonlinear >0.05). Subgroup analysis further confirmed that this association remained consistent across different populations.

CONCLUSIONS

A higher ALBI score was associated with increased ACM in a selected intensive care unit (ICU) cohort with International Classification of Diseases (ICD)-coded PE. However, its clinical utility and PE-specific prognostic value remain uncertain and need to be prospectively validated.