Sex differences in atrial fibrillation-related mortality in critically ill patients with heart failure

Abstract Background The adverse outcomes associated with atrial fibrillation (AF) have been studied in patients with heart failure (HF). However, sex differences in outcomes associated with AF merit further investigation. Purpose We aimed to evaluate the sex-specific associations of AF with mortality in a critically ill population with HF. Methods The retrospective study was based on the Medical Information Mart for Intensive Care IV database. The primary outcome was 1-year mortality. Results In total 11121 patients (median age 75.7 years; 5017 women [45.1%]) were included. There were 2107 (19.0%) patients with pre-existing AF and 3486 (31.4%) with new-onset AF. The association of AF with 1-year mortality, estimated with rate ratios (rate in new-onset AF vs rate in no AF per 1000 person-days) differed by sex. The rate ratio (95% confidence interval) for one-year mortality in female patients was 1.57 (1.42, 1.74), compared with 1.38 (1.25, 1.51) in male patients. In the multivariate COX survival analysis, new-onset AF was associated with an 29.7% increased risk of one-year mortality (p < 0.001) in the overall cohort, with 41.7% in female patients (p < 0.001) and 20.0% in male patients (p < 0.001). In the Kaplan-Meier analysis, female patients with new-onset AF had the worst 1-year survival than other patients. Conclusions In critically ill HF patients, new-onset AF was associated with a greater risk for long-term mortality in female patients than in male patients.