Non-Vitamin K Oral Anticoagulants for Stroke Prevention in Special Populations with Atrial Fibrillation

Atrial fibrillation (AF) is associated with an increased risk of ischemic stroke or systemic embolism compared with normal sinus rhythm. These strokes may efficiently be prevented in patients with risk factors using oral anticoagulant therapy, with either vitamin K antagonists (VKAs) or non-vitamin K antagonist oral anticoagulants (NOACs) (i.e., direct thrombin inhibitors or direct factor Xa inhibitors). Owing to their specific risk profiles, some AF populations may have increased risks of both thromboembolic and bleeding events. These AF patients may be denied oral anticoagulants, whilst evidence shows that the absolute benefits of oral anticoagulants are greatest in patients at highest risk. NOACs are an alternative to VKAs to prevent stroke in patients with "non-valvular AF", and NOACs may offer a greater net clinical benefit compared with VKAs, particularly in these high-risk patients. Physicians have to learn how to use these drugs optimally in specific settings. We review concrete clinical scenarios for which practical answers are currently proposed for use of NOACs based on available evidence for patients with kidney disease, elderly patients, women, patients with diabetes, patients with low or high body weight, and those with valve disease.