30-Day Outcomes Associated With Atrial Fibrillation in Patients With Heart Failure and Reduced and Preserved Ejection Fraction

Background: The relative impact of atrial fibrillation (AF) on 30-day outcomes for patients with heart failure with reduced ejection fraction (HFrEF) and heart failure with preserved ejection fraction (HFpEF) is unknown. Methods: Retrospective cohort study of clinical registry data linked to Medicare claims for HFrEF and HFpEF patients discharged home alive and stratified by presence of AF at admission. Outcomes of interest were post discharge mortality and all-cause readmission at 30 days. We used Kaplan-Meier methods to estimate mortality and calculated cumulative incidence estimates for all-cause readmission. We used Cox proportional hazards models to examine adjusted associations between AF and 30-day mortality and readmission in patients with heart failure. Results: Among 47,453 HF patients (45.7% HFrEF, 54.3% HFpEF) admitted to 283 hospitals between January 2001 and March 2006, 44.6% of patients had AF (42.8% of HFrEF patients, 46.1% of HFpEF patients). All-cause unadjusted 30-day readmission was more frequent among patients with comorbid AF than those without (HFrEF patients: 24.0% vs. 22.3%, p=0.003; HFpEF patients: 21.4% vs. 20.2%, p=0.01). After adjustment for other patient factors (Table), AF was not associated with a higher hazard of 30-day mortality among all HF patients but was associated with a higher hazard of 30-day readmission (HR 1.06; 95% CI 1.02, 1.11). In subgroup analyses by HF type, the association of AF with a higher risk for 30-day readmission was significant only for HFpEF patients (HR 1.07; 95% CI 1.01, 1.14) and not HFrEF patients. Conclusion: Atrial fibrillation was not associated with 30-day mortality in HFrEF or HFpEF patients, but was associated with modestly higher 30-day readmission among HFpEF patients. The management of HF should remain a primary focus of provider efforts to reduce 30-day readmission and mortality rates.