Atrial fibrillation (AF), the most common arrhythmia, is associated with a significantly increased risk of morbidity and mortality due to a fivefold increase in the frequency of thromboembolic stroke.1 The gold standard treatment for the prevention of AF-related thromboembolism is oral anticoagulation (OAC), based on an individualised patient risk assessment with either the CHADS2 or the CHA2DS2-VASc score.2 However, up to 20 % of patients with AF cannot take OAC therapy,3 and there exists a considerable bleeding risk among those that can tolerate OAC: intracranial bleeding occurs in 1 % of patients taking warfarin per annum, whereas survivors of a haemorrhagic stroke are generally considered inappropriate for anticoagulation for life.4,5 In addition, OAC is associated with significant morbidity and its associated cost implications: for example, OAC-related gastrointestinal (GI) bleeding causes repeated hospitalisations and blood transfusions, and carries a mortality rate of up to 10 %.6 The HASBLED score is the most widely used tool to estimate the risk of major bleeding for patients on OAC therapy.7 Novel OACs have been shown to be either non-inferior or superior to warfarin therapy with equivalent or decreased bleeding events. Nevertheless, there remains an annual 2–3 % incidence of major bleeding.8