Comprehensive overview of atrial fibrillation trends in Estonia: a population-based cohort study from 2017 to 2024

Aims Atrial fibrillation (AF) has been reported to affect approximately 2–4% of adults and imposes a healthcare burden, yet contemporary nationwide data capturing modern AF care remain limited. We aimed to describe population-level trends of AF incidence, prevalence, procedures, comorbidities and outcomes among adults in Estonia from 2017 to 2024.Methods and results This population-based cohort study assessed linked electronic health records and healthcare claims for a 30% random sample of the adult Estonian population, harmonised to the Observational Medical Outcomes Partnership common data model. Incident AF was defined as the first International Statistical Classification of Diseases and Related Health Problems 10th Revision code I48 with no prior diagnosis during lookback period. Incidence and prevalence were estimated using Poisson regression models, while 1-year hospitalisation was assessed using competing-risk methods, whereas mortality comparisons were performed using Cox proportional hazards regression. We identified 15 197 incident AF cases from 2017 to 2024. The crude AF incidence decreased from 846.1 to 732.3 per 100 000 person-years while prevalence increased from 5.9% to 7.1% (p<0.05 for both). Crude AF prevalence was higher in females than males (7.1% vs 7.0% in 2024, p<0.05), whereas age-standardised prevalence among adults aged ≥20 years was higher in males (8.0% vs 5.2%). The 1-year cumulative incidences of all-cause hospitalisation and mortality were 25.2% and 13.7%, respectively, with mortality remaining stable between 2017 and 2023.Conclusion Despite declining incidence, AF prevalence increased, consistent with an accumulation of prevalent disease in an elderly population. Early all-cause mortality after AF diagnosis remains high, emphasising the considerable comorbidity burden of contemporary AF populations.