Antithrombotic therapy in patients with non-valvular atrial fibrillation in Southern Sweden: A population-based cohort study

- Guideline adherence increased from 47.6% in 2011 to 66.1% in 2014.
- Use of ASA more common among elderly or patients at higher stroke- and bleeding risk
- 47% of patients at risk undertreated, particularly women < 65 years and elderly
- Overtreatment of patients at low stroke risk was 35.9% in men and 36.4% in women.
- Provider specialty affected the choice of treatment only to a minor degree.

IntroductionOral anticoagulants in patients with atrial fibrillation (AF) with moderate-to-high stroke risk are strongly recommended by the current guidelines.Materials and methodsPopulation-based register study of all 13,837 patients with incident non-valvular AF diagnosed during 2011-2014 in primary and secondary care (including all in- and outpatient visits) in Skåne County, Sweden. The outcome was the prescription of direct-acting oral anticoagulants (DOAC), warfarin or acetylsalicylic acid (ASA).Results and conclusionGuideline adherence increased from 47.6% in 2011 to 66.1% in 2014, mostly due to decrease in undertreatment. In patients with CHA2DS2-VASc score ≥ 2, ASA uptake decreased from 29.9% to 14.7% and DOAC uptake increased from 2.1% to 25.1%. The use of ASA was more common among elderly and with increasing stroke- and bleeding risk. Overall, 47.4% of patients with CHA2DS2-VASc score ≥ 2 did not receive oral anticoagulants. Undertreatment was particularly common in women < 65 years (55.8%) and in patients > 84 years (65.3% in women and 62% in men). Overtreatment of patients at low stroke risk was 35.9% in men and 36.4% in women. Provider speciality affected the choice of treatment only to a minor degree. Despite increasing guideline adherence, there is a suboptimal use of antithrombotic therapy in a large proportion of AF patients diagnosed in different clinical settings. Efforts to further improve guideline adherence should particularly be targeted on women < 65 years, elderly > 84 years and patients at low stroke risk.