Aims: To determine whether changing patterns of anticoagulant use in atrial fibrillation (AF) have impacted on stroke rates in England.
Methods and results: English national databases, 2006-2016, were interrogated to assess stroke admissions and oral anticoagulant use. The number of patients with known AF increased linearly from 692 054 to 983 254 (prevalence 1.29% vs. 1.71%). Hospital episodes of AF-related stroke/100 000 AF patients increased from 80/week in 2006 to 98/week in 2011 and declined to 86/week in 2016 (2006-2011 difference 18.0, 95% confidence interval (CI) 17.9-18.1, 2011-2016 difference -12.0, 95% CI -12.1 to -11.9). Anticoagulant use amongst patients with CHA2DS2-VASc ≥2 increased from 48.0% to 78.6% and anti-platelet use declined from 42.9% to 16.1%; the greatest rate of change occurred in the second 5 year period (for anticoagulants 2006-2011 difference 4.8%, 95% CI 4.5-5.1%, 2011-2016 difference 25.8%, 95% CI 25.5-26.1%). After adjustment for AF prevalence, a 1% increase in anticoagulant use was associated with a 0.8% decrease in the weekly rate of AF-related stroke (incidence rate ratio 0.992, 95% CI 0.989-0.994). Had the use of anticoagulants remained at 2009 levels, 4068 (95% CI 4046-4089) more strokes would have been predicted in 2015/2016.
Conclusion: Between 2006 and 2016, AF prevalence and anticoagulant use in England increased. From 2011, hospitalized AF-related stroke rates declined and were significantly associated with increased anticoagulant uptake.