The burden of atrial fibrillation on emergency medical services: A population-based cohort study

Background: Atrial fibrillation (AF) is a growing burden on healthcare resources, despite improvements in prevention and management. AF is a common cause of hospitalisation, and Emergency Medical Services (EMS) use. However, there is a paucity of data describing the burden of AF on EMS. We aimed to determine the prevalence, characteristics, and outcomes of patients presenting with AF to EMS using a large population-based sample. Methods: Consecutive attendances for AF in Victoria, Australia (January 2015-June 2019) were included if patients had a diagnosis of "AF" or "arrhythmia" with AF on electrocardiogram. Data were individually linked to emergency, hospital, and mortality records. Results: Of 2,613,056 EMS attendances, 16,525 were a first attendance for AF and linked to hospital records. Median (IQR) age was 76 (67,84) years (43% female). Seventy-eight percent had high thromboembolic risk (CHA(2)DS(2)-VASc score >= 2), and 72% had a heart rate >= 100 bpm. Forty-two percent of patients received no treatment by paramedics and 99.4% were transported to hospital. Fifty-three percent were discharged from ED. Median length of hospital stay was 2 days. Of 2542 cases reattended for AF, 19% occurred within 30 days, with increased odds for females and those of low socioeconomic status. Overall, 24% died during the study period, 12% within 30 days. Increasing age, heart failure, stroke, COPD, and low socioeconomic status increased the odds of 30-day mortality. Conclusions: EMS utilisation for AF is common and associated with frequent reattendance. Further studies are required to investigate novel pathways of care to reduce AF burden on healthcare systems.