Background: Underuse of oral anticoagulation (OAC) for stroke prevention in atrial fibrillation (AF) results in thousands of preventable strokes in Germany each year. This study aimed to assess changes in antithrombotic therapy in AF patients after increased use of direct oral anticoagulants (DOACs) in Germany and to evaluate whether the adoption of DOAC therapy was associated with changes in AF-related stroke and bleeding over time.
Methods: Analyses were carried out on a large claims-based dataset of 4 million health-insured Germans. The study population consisted of 601,261 prevalent AF patients between 2011 and 2016 who were assigned to one of the following four treatment groups: DOAC, VKA, antiplatelets or no antithrombotic treatment. Treatment patterns were descriptively analysed and represented by cohort and CHA2DS2-VASc score. Clinical outcomes before and after the adoption of DOAC therapy were assessed using Poisson regression models.
Results: Use of OAC increased from 42 to 61% between 2011 and 2016, mainly due to more frequent prescription of DOACs. However, some underuse of OAC therapy remained even in high risk AF patients. In parallel with the increased prescription rate of OAC, there was an overall 24% incidence reduction in stroke between 2011 and 2016 which was mainly driven by reductions in ischemic strokes. Over the same time period the risk for major bleeding remained unchanged.
Conclusion: Between 2011 and 2016, the use of guideline-conform antithrombotic therapy in Germany has significantly increased. This was associated with a significant decline in strokes without an increased incidence of bleeding complications.
Keywords: Atrial fibrillation; Direct oral anticoagulants; Oral anticoagulation; Stroke; VKA.