Improving the use of direct oral anticoagulants in atrial fibrillation

Abstract

The need for anticoagulation in patients with atrial fibrillation (AF), and the inherent limitations of warfarin have fostered the search for direct oral anticoagulant drugs (DOACs). In recent years, inhibitors of thrombin (Dabigatran etexilate) and of activated factor X (Rivaroxaban, Apixaban) have become clinically available, and current guidelines of the European Society of Cardiology recommend their use in AF patients. However, limitations and uncertainties as to their clinical handling have emerged. With the exception of those on Dabigatran, caution is presently recommended in patients undergoing ablation for AF, and in those who need dual antiplatelet treatment and/or invasive procedures. The use of DOACs is precluded in patients with (mechanical) heart valves, severe kidney or liver failure, malignancy, in those on prasugrel or ticagrelor, in those with the need for coronary stenting, and in naive patients with AF who need cardioversion. Moreover it must be borne in mind that limited long-term efficacy and safety data are available and that adherence of patients to DOACs may be a major issue in the real-life setting. The definition and type of monitoring to be employed to evaluate adherence to DOACs is lacking, nor have we practical guidelines on how to handle bleeding in patients on DOACs. Finally, ad hoc validated definitions of therapeutic failures are crucial in cost/utility analyses, but these are not available for DOACs. Thus, caution, vigilance and further clinical data are mandatory for a safe and appropriate use of DOACs as alternatives to warfarin in AF patients in real-life clinical settings.