Atrial Fibrillation and Stroke

Abstract

Atrial fibrillation (AF) represents a major cause of morbidity and mortality in adults, especially for its strong association with thromboembolism and stroke. In this chapter, we aim to provide an overview on this cardiac arrhythmia, addressing several important questions. Particularly, we faced the possible mechanisms leading to an increased risk of embolism in AF, emphasizing how Virchow’s triad for thrombogenesis is unable to fully explain this risk. Disentangling the risk of stroke caused by AF and by other associated vascular conditions is extremely challenging, and risk stratification of patients with AF into those at high and low risk of thromboembolism has become a crucial determinant of optimal antithrombotic prophylaxis. Moreover, we discuss the typical clinical and radiological characteristics of cardioembolic strokes, addressing acute, time-dependent reperfusional therapies in case of ischemic stroke. The role of anticoagulation in AF is also fully analyzed; the benefit of oral anticoagulation generally outweighs the risk of bleeding in AF patients, and a variety of scoring systems have been developed to improve clinical decision-making when initiating anticoagulation. With their predictable pharmacokinetic profiles, wide therapeutic windows, fewer drug–drug and drug-food interactions, and the non-vitamin K antagonist (VKA) oral anticoagulants (NOACs) have changed the landscape of thromboprophylaxis for AF patients, offering the opportunity to use effective anticoagulants without the need for intensive therapeutic drug monitoring.