Prognostic value of red blood cell distribution width combined with chloride in predicting short- and long-term mortality in critically ill patients with congestive heart failure: Findings from the MIMIC-IV database

Background: Hypochloremia and red blood cell distribution width (RDW) play important roles in congestive heart failure (CHF) pathophysiology, and they were associated with the prognosis of CHF. However, the prognostic value of chloride combined with RDW in patients with CHF remains unknown.

Methods: We retrospectively analyzed critically ill patients with CHF. The database was derived from the Medical Information Mart for Intensive Care IV v2.0 (MIMIC-IV-v2.0) database.

Results: In the final analysis, 5376 critically ill patients with CHF were included, and 2428 patients (45.2 %) experienced 5-year mortality. The restricted cubic spline model revealed a positive correlation between RDW and 5-year mortality, whereas chloride showed a U-shaped correlation with 5-year mortality. The median values of RDW and chloride were used to classify patients into four groups: high chloride/low RDW, low chloride/low RDW, high chloride/high RDW, and low chloride/high RDW. We observed the prognostic value of RDW combined with chloride in the Cox proportional hazard model, in predicting 5-year mortality, in-hospital mortality and 1-year mortality. Furthermore, we discovered that patients with chronic kidney disease (CKD) had a higher 5-year mortality risk than patients without CKD.

Conclusion: We found the translational potential role of chloride combined with RDW in prioritizing patients at high risk for short- and long-term mortality in a cohort of critically ill patients with CHF. Prospective multicenter investigations are warranted to validate our results.