Uncovering the Role of Direct Oral Anticoagulants in Stroke Prevention for Atrial Fibrillation: A Review of the Literature

Abstract

Atrial fibrillation (AF) is a predominant contributor to morbidity and mortality, and stroke prevention remains the mainstay for the management of AF. The precise mechanism involved in thrombus formation remains unknown. However, factors such as stretch-induced fibrosis, endothelial dysfunction, disordered atrial contractions, and pro-thrombotic states have been postulated for the development of AF. Various risk assessment strategies have been acknowledged for determining the risk of stroke in AF, of which the congestive heart failure, hypertension, age ≥75, diabetes, stroke, vascular disease, age between 65-74, and female sex (CHA2DS2-VASc) score remains the ultimate risk stratification tool. For the longest time, vitamin K antagonists (VKA) were the only oral anticoagulants available but were associated with an increased risk of bleeding. Recently, direct oral anticoagulants (DOACs) were approved and considered more efficient and safer than or as secure as warfarin in stroke prevention and lowering intra-cranial bleeding events. The pharmacodynamics and pharmacokinetics of DOACs were also clarified in this article. This review article compiles current evidence-based data on the role of DOACs, uncovering their underlying mechanisms, and comparing their efficacy with warfarin in stroke prevention in AF.