The Trends in Utilizing Nonvitamin K Antagonist Oral Anticoagulants in Patients With Nonvalvular Atrial Fibrillation

Abstract

Dabigatran and rivaroxaban are novel nonvitamin K antagonist oral anticoagulants (NOACs) approved for thromboprophylaxis in atrial fibrillation (AF). In Turkey, like other countries, the efficacy of translation of the clinical trial results and current guideline recommendations into daily clinical practice is yet to be discovered. Using data from medical records of three tertiary care cardiology centers, we identified patients with nonvalvular AF on dabigatran or rivaroxaban treatment. Baseline characteristics and utilization trends were compared between dabigatran and rivaroxaban groups. Secondarily, clinical events including ischemic stroke and/or transient ischemic attack, systemic embolism, and bleeding were evaluated. Among 294 patients with AF included, dabigatran was utilized in 177 (60.2%) and rivaroxaban in 117 (39.8%). Overall, 76% of patients had received long-term warfarin therapy. The use of 110 mg twice a day (55.4%) was the prevailing strategy in dabigatran group, whereas in rivaroxaban group 20 mg every day (67.5%) was the preferred option. Of the patients, 37.3% had severe valvular disease in which mitral regurgitation was the predominant valve abnormality. Scores of CHADS2, CHA2DS2VASc, and HAS-BLED were similar in both the groups. Of the patients, 24% in dabigatran group and 13.7% in rivaroxaban group were prescribed the lower dose inappropriately. The two NOACs did not differ significantly in terms of clinical events. The results of this study indicate that in daily practice, the physicians’ behavior in utilizing the NOACs is shaped by the clinical trials and the guideline recommendations. On the other hand, in dose selection, this adherence is not of high quality.