Advances in Atrial Fibrillation-related Stroke Prevention

Abstract

In patients with atrial fibrillation (AF) the risk of stroke is substantially increased, especially in those who are elderly (over 75 years) or have risk factors such as previous stroke, heart failure or hypertension. Stroke outcomes are also generally much worse in those with AF. Current guidelines indicate that any patient with AF and risk factors for stroke should receive anticoagulant therapy to limit their stroke risk. Despite these established recommendations, only 50 % of patients at risk receive anticoagulation with a vitamin K antagonist (VKA) and only 50 % of those are within the therapeutic range, indicating lack of adherence to the guidelines. Withholding anticoagulant therapy is mainly left to an individual physician’s choice, as shown in the ongoing GARFIELD registry of AF stroke prevention practice. Many physicians fear the risk of intracranial haemorrhage (ICH) for which outcomes remain poor. Recent clinical studies have shown that the non-VKA oral anticoagulants (NOACs) (apixaban, rivaroxaban, dabigatran and edoxaban) significantly reduce the risk of ICH and other bleeding events, while having non-inferior stroke prevention to warfarin. Use of these drugs, limiting exposure to aspirin and alcohol and controlling blood pressure have been shown to minimise ICH risk in large clinical trials and meta-analyses. Recent data from the Effective aNticoaGulation with factor xA next GEneration in Atrial Fibrillation (ENGAGE AF)-TIMI 48 study showed that the factor Xa inhibitor edoxaban was non-inferior to well-managed warfarin for reducing all stroke risk, and significantly reduced haemorrhagic stroke, major bleeding, ICH and death. These findings further support the case for using NOAC therapy for stroke prevention in patients with AF and risk factors for stroke.