Atrial fibrillation (AF) is the most frequent cardiac arrhythmia, which is associated with an enhanced risk for stroke and myocardial infarction [1–3]. Vitamin K antagonists (VKAs) have been the golden standard for stroke prophylaxis but they are associated with a significant risk of bleeding [4]. VKAs are unsuitable for many patients, due to difficulties related to the frequent need for check of INR values, or to difficulties in achieving and maintaining an adequate Time in Therapeutic Range (TTR).