Association between red cell distribution width and all-cause mortality in patients with congestive heart failure and atrial fibrillation.

BACKGROUND

The role of red cell distribution width (RDW) in critically ill patients with congestive heart failure (CHF) and atrial fibrillation (AF), requiring intensive care unit (ICU) admission, remains unclear. This study aimed to investigate the association between RDW and the clinical prognosis of critically ill patients with CHF and AF.

METHODS

This retrospective observational cohort study utilised data from the Medical Information Mart for Intensive Care-IV (MIMIC IV2.2) database. Participants were categorised into four groups based on RDW. The primary outcome was hospital all-cause mortality. Multivariable logistic proportional regression analysis and restricted cubic spline regression were employed to assess the RDW's association with hospital mortality in patients with CHF and AF. Sensitivity analysis included determining the RDW's feature importance through subgroup analysis in different subgroups.

RESULTS

A total of 10879 patients were included in the study, with an in-hospital mortality of 11.5%, respectively. Multivariate logistic regression analysis demonstrated that the RDW was independently associated with an increased risk of in-hospital mortality (odds ratio (OR) = 1.18, 95% confidence interval (CI): 1.14-1.21, p < 0.001) after adjusting for confounders. The restricted cubic spline regression model indicated a non-linear increase in the risks of in-hospital mortality with a higher RDW. In patients with CHF and AF whose RDW is less than 16.565, the in-hospital mortality increased significantly(OR = 1.335, 95% CI 1.231-1.448, p < 0.001). Sensitivity analysis revealed consistent effect sizes and directions in different subgroups, ensuring result stability.

CONCLUSIONS

The results of our study suggest a significant association between the RDW and all-cause mortality in critically ill patients with CHF and AF.