Predictive value of red blood cell distribution width in critically ill patients with atrial fibrillation: a retrospective cohort study.

BACKGROUND:Atrial fibrillation (AF) is a leading cause of morbidity and mortality among elderly patients especially for patients in ICU. Previous studies revealed the impact of red blood cell distribution width (RDW) on predicting onset of AF. However, the prognostic value of RDW in critically ill patients with AF remains largely unknown. Thus, this study aims to explore the potential value on predicting in- and out-of-hospital mortality in critically ill patients with AF. METHODS:Data were extracted from the Medical Information Mart for Intensive Care (MIMIC) III database and 7,867 critically ill patients with AF were enrolled. The association between RDW and inhospital mortality was evaluated using the multiple logistic regression analysis as a design variable. Shortand long-term outcomes were compared between the low RDW and high RDW groups in critically ill patients balanced by the propensity score matching (PSM) algorithm. RESULTS:Analysis of the 7,867 patients revealed a linear relationship between RDW and in-hospital mortality. For critically ill patients with AF, the elevated level of RDW was associated with increased inhospital mortality, with the OR increasing from level 2 (OR: 1.75, 95% CI: 1.25 to 2.44) to level 5 (OR: 3.89, 95% CI: 2.55 to 5.93) with level 1 (RDW ≤13) as the reference group. 3841 enrolled patients with records in the CareVue systems were selected by PSM algorithm. The baseline characters were well balanced in 1,054 pairs of enrolled patients. A significant lower survival rate was observed in the high RDW group (P<0.001). CONCLUSIONS:High levels of RDW are associated with increased in- and out-of-hospital mortality in critically ill patients with AF.