Stroke in atrial fibrillation: epidemiology and thromboprophylaxis.

Atrial fibrillation (AF) is the commonest sustained cardiac rhythm disorder, which is associated with a substantial risk of mortality and morbidity arising from stroke and thromboembolism. Extensive epidemiological evidence and robust data from clinical trials have shown that stroke and thromboembolism in AF can be prevented by oral anticoagulation (OAC). Despite this evidence and guidelines, appropriate thromboprophylaxis is still suboptimal, and this is partly due to the only OAC agent being available is the vitamin K antagonist class of drugs (e.g. warfarin) that has many limitations and disadvantages. With the availability of new OAC agents that avoid the disutility of the vitamin K antagonists, it is hoped that greater use of OAC would allow more effective thromboprophylaxis and have a great impact on preventing strokes related to AF. Additionally, stroke risk assessments need to evolve such that they are better at identifying the 'truly low risk' subjects who do not need antithrombotic therapy, whilst all other patients with ≥ 1 stroke risk factors can be considered for OAC. The availability of comprehensive stroke and bleeding risk assessments would enable us to make informed decisions in everyday clinical practice. The aim of the review article is to provide a state-of-the-art overview of the clinical epidemiology of stroke in AF, stroke (and bleeding) risk assessments and the current provision of thromboprophylaxis for patients with AF.