Abstract 13772: Anticoagulation Guideline Adherence in 4,500 Patients With Newly Diagnosed Atrial Fibrillation: Insights From the Prospective DUTCH-AF Registry

Introduction: Non-adherence to guidelines and off-label dosing of oral anticoagulants (OAC) is common in atrial fibrillation (AF), but the extent hereof in newly diagnosed AF patients is uncertain. Methods: The DUTCH-AF registry prospectively enrolls patients with newly diagnosed AF since July 2018. We used data available up to November 2020. Anticoagulation guideline and label adherence were assessed at diagnosis of AF using the 2016 European guideline recommendations and the European Medicines Agency labelling. Predictors for label non-adherence were assessed using logistic regression. Results: Throughout the Netherlands, 4,500 patients were registered in DUTCH-AF. Mean age was 69.6±10.5 years, 41.5% were female. Anticoagulants were prescribed in 90.1% of patients with a class I OAC recommendation. In patients with a class IIa OAC recommendation, females were more often treated with anticoagulation than males (89.6% vs 81.2%, p<0.001). Antiplatelet monotherapy and vitamin K antagonists were used infrequently, but its use was most common in patients with a high predicted stroke risk. Off-label use of non-vitamin K oral anticoagulants was uncommon (6.2%), but of the 394 patients who were prescribed a reduced dose, 34.3% were treated off-label (Figure). Independent predictors for off-label reduced dose use were (i) older age (odds ratio (OR) 1.07 per year, 95%-confidence interval (CI) 1.04-1.11, p<0.001), (ii) lower creatinine clearance (OR 0.95 per ml/min, 95%-CI 0.94-0.96, p<0.001), (iii) lower body mass index (OR 0.95 per kg/m 2 , 95%-CI 0.91-1.00, p=0.04) and (iv) concomitant antiplatelet therapy (OR 4.19, 95%-CI 1.88-9.34, p<0.001). Conclusion: In newly diagnosed Dutch AF patients, non-adherence to anticoagulation guidelines and off-label dosing at diagnosis are uncommon, with deviations from recommendations seen more frequently in high-risk patients. These results provide important insights for practicing clinicians.