Trends in preadmission oral anticoagulant use and clinical outcome in atrial fibrillation patients admitted with acute stroke in Denmark

Aims: Use of oral anticoagulation (OAC) therapy has increased in recent years among patients with atrial fibrillation (AF). However, it remains uncertain whether this translates into improved clinical outcomes. We aimed to examine time trends in preadmission OAC use and clinical outcomes among AF patients admitted with stroke. Methods and results: We used nationwide registries to perform a follow-up study of 14 999 patients with AF who were admitted with acute stroke to a Danish hospital between 2008 and 2016. The proportion of AF-related stroke was 16.1% in 2008 and 17.6% in 2016. Among patients with AF-related stroke, the overall proportion of preadmission OAC users increased from 22.6% in 2008 to 41.5% in 2016. Between 2008 and 2016, the proportion of patients with AF admitted with severe stroke declined from 32.4% to 27.4% [adjusted odds ratio (OR) = 0.78, 95% confidence interval (CI): 0.75-0.81], the median length of hospital stay (LOS) decreased from 12 to 8 days (adjusted hazard ratio of discharge = 1.32, 95% CI: 1.30-1.34) and 30-day mortality decreased from 19.2% to 13.7% (adjusted OR = 0.72, 95% CI: 0.68-0.75). Conclusion: The incidence of AF-related strokes remains high although preadmission use of OAC has increased substantially in recent years. Despite the proportion of OAC users almost doubled from 2008 to 2016, a sizeable proportion of AF patients is still without OAC when admitted with stroke. The increased use of OAC has been accompanied by a lower proportion of patients with severe stroke, shorter LOS, and lower mortality.