Remoteness and emergency care pathways for ambulance-attended atrial fibrillation: a population-based linked cohort study.

Background: Atrial fibrillation (AF) frequently requires emergency medical services (EMS), but acute-care pathways may differ by remoteness. We examined ambulance-attended AF care and outcomes across Victoria, Australia. Methods: We conducted a population-based linked cohort study of first ambulance-attended AF events from Jan 1, 2015, to June 30, 2019. Residence was classified using ARIA+ as major cities, inner regional, or outer regional/remote. We estimated incidence rate ratios (IRRs) and used adjusted logistic regression to compare care pathways, rhythm-control procedures, EMS re-attendance, and mortality. Results: Among 16,372 events, 11,914 (72.8%) occurred in major cities, 3691 (22.5%) in inner regional areas, and 767 (4.7%) in outer regional/remote areas. Annualised incidence was higher in inner regional (IRR 1.31, 95% CI 1.27-1.36) and outer regional/remote areas (IRR 1.25, 95% CI 1.16-1.35) than in major cities. Transport to hospital exceeded 99% across groups. Transport longer than 60 min increased with remoteness (0.7%, 6.4%, and 11.2%), whereas offload delay was concentrated in major cities (69.6%, 46.2%, and 35.9%). Rhythm-control procedures, EMS re-attendance for AF, and mortality were similar after adjustment, whereas socioeconomic disadvantage was associated with fewer rhythm-control procedures and higher mortality independently of remoteness. Conclusions: Ambulance-attended AF is more frequent outside major cities and imposes greater transport burden, while metropolitan care is more affected by offload delay. Similar outcomes should not be interpreted as similar care. AF pathways should target ED flow in cities and prehospital triage and follow-up outside cities. Research in context: Evidence before this studyAF is a major contributor to emergency care use, hospitalisation, stroke, and mortality. Prior statewide Victorian studies have described the overall ambulance and ED burden of AF, while international literature suggests that rural patients experience barriers to AF diagnosis, specialist care, and longitudinal management. However, few population-based linked data studies have compared the full prehospital-to-hospital pathway for ambulance-attended AF by remoteness of residence.Added value of this studyThis study links statewide EMS, ED, hospital, and mortality data to show that ambulance-attended AF incidence is higher in regional Victoria and that prolonged transport is substantially more common outside major cities. Conversely, offload delay is concentrated in major cities. Despite these pathway differences, adjusted EMS re-attendance, mortality, and rhythm-control procedure rates were similar across remoteness categories, whereas area-level socioeconomic disadvantage was associated with fewer rhythm-control procedures and higher mortality regardless of where patients lived.Implications of all the available evidenceStatewide AF pathways should not assume that the same bottleneck applies everywhere. Metropolitan strategies should address ED congestion and offload delay, while rural implementation should prioritise transport burden, prehospital risk stratification, and reliable follow-up after ED discharge or non-transport. Socioeconomic disadvantage cuts across both settings and warrants attention in its own right.