Emergent readmission and long-term mortality risk after incident atrial fibrillation hospitalisation

Objective: To assess the frequency and predictors of unplanned readmissions after hospitalisation for incident atrial fibrillation (AF) and the association of readmissions with mortality over 2 years.

Methods: We performed a retrospective cohort study using Western Australian morbidity and mortality data to identify all patients, aged 25-94 years, who survived incident (first-ever) hospitalisation for AF (principal diagnosis), between 2001 and 2015. Ordinal logistic models determined the covariates independently associated with unplanned readmission(s), and Cox proportional hazards models with time-varying exposures determined the hazard ratios (HR) of one or more readmissions for mortality over 2 years after incident AF.

Results: Of 22 956 patients, 57.7% male, mean age 67.9 (SD 13.8) years, 44.0% experienced 22 053 unplanned readmissions within 2 years, 50.6% being cardiovascular-related. All-cause death occurred in 8.0% of the cohort, and the multivariable-adjusted mortality HR of 1 (vs 0) readmission was 2.9 (95% CI 2.6 to 3.3), increasing to 5.6 (95% CI 5.0 to 6.5) for 3+ readmissions. First emergent readmission for AF, stroke, heart failure or myocardial infarction was independently associated with an increased hazard for mortality. Coexistent cardiovascular and other comorbidities were independently associated with increased readmission and mortality risk, whereas AF ablation was associated with reduced risk.

Conclusion: This study highlights the large burden of unplanned all-cause and cardiovascular-specific readmissions within 2 years after being hospitalised for incident AF and their associated adverse impact on mortality. Concomitant comorbidities are independently associated with unplanned hospitalisations and mortality, which supports integrated multidisciplinary management of comorbidities, along with AF-targeted treatments, to improve long-term outcomes in patients with AF.