Trends and Predictors of Oral Anticoagulation in Patients with Atrial Fibrillation: A Serial Cross-Sectional Study from 2011 to 2016

Abstract Background: Despite the efficacy of vitamin K antagonists against stroke in patients with atrial fibrillation (AF), the underuse of this therapy is well documented. Objectives: To evaluate trends and predictors of oral anticoagulants utilization in patients with AF. Methods: Observational, retrospective, serial cross-sectional study between 2011-2016. Comparisons between groups were performed using the Student t, Mann-Whitney and Chi-square tests. Logistic regression was used to identify independent predictors of anticoagulation. A p value < 0.05 was considered significant. Results: A total of 377 patients were analyzed. The mean age was 70 ± 15 years; 52% were male and 75% were anticoagulated (20% with VKA and 55% with DOAC). Over 5 years, the overall frequency of anticoagulation increased by 22.4%. The use of DOACs increased from 29% to 70%, whereas the use of VKA decreased from 36% to 17%. The use of antiplatelet agents alone also fell from 21% to 6%. The predictors of anticoagulation were previous episodes of AF (OR 3.1, p < 0.001), hypertension (OR 3.0, p < 0.001) and HASBLED score (OR 0.5, p < 0.001). The predictors of DOAC use were serum creatinine (OR 0.2, p = 0.002), left atrial size (OR 0.9, p = 0.003) and biological valve prosthesis (OR 0.1, p = 0.007). Of the 208 patients using DOACs, 63 (30%) received inadequate prescriptions: 5 with severe drug interactions and 58 with incorrect dosing. Conclusions: Between 2011 and 2016, DOACs were rapidly incorporated into clinical practice, replacing AVKs and antiplatelets, and contributing to greater use of anticoagulation in patients with AF.