Stroke Prevention in Atrial Fibrillation - Outcomes and Future Directions

Stroke prevention is central to the management of patients with atrial fibrillation (AF). Vitamin K antagonists (VKAs) are the established and long-standing option for stroke prevention therapy in patients with AF. However, non-VKA oral anticoagulants (NOACs) have recently been developed and demonstrated non-inferior efficacy vs VKA treatment, with fewer limitations in clinical practice and with reduced risks of major bleeding. In order to discuss the usage, efficacy and safety of NOACs, a satellite symposium was held at the Cardiostim/ EHRA Europace Congress in Nice in June 2014. At present, three NOACs, a direct thrombin inhibitor (dabigatran) and two direct factor Xa inhibitors (rivaroxaban and apixaban) have been approved in Europe for stroke prevention in patients with AF. In addition, the once-daily factor Xa inhibitor edoxaban has recently been evaluated in this setting in the phase III Effective Anticoagulation with Factor Xa Next Generation in Atrial Fibrillation - Thrombolysis In Myocardial Infarction Study 48 (ENGAGE AF-TIMI 48) that compared edoxaban 30 mg once daily (low-dose regimen) with dose-adjusted warfarin (international normalised ratio 2.0-3.0). ENGAGE AF-TIMI 48 was the largest trial with a NOAC to date, and demonstrated that both dosing regimens of once-daily edoxaban were non-inferior to well-managed warfarin treatment for the prevention of stroke or systemic embolism and also provided significant reductions in the risk of haemorrhagic stroke, cardiovascular mortality, major bleeding and intracranial bleeding. In summary, the recent availability of NOACs has enabled physicians to avoid the limitations of VKA therapy in clinical practice and tailor anticoagulant treatment to the individual patient. However, worldwide usage of oral anticoagulant therapy remains suboptimal compared with guideline recommendations, and further dissemination of its benefits may prove helpful.