title: Antithrombotic therapy in nonvalvular atrial fibrillation: a narrative review.
abstract: Atrial fibrillation (AF) is an important and potentially modifiable cause of stroke. It has been known since 1989 that oral anticoagulant drugs, such as warfarin, lead to a dramatic decrease in stroke associated with AF. The best risk-benefit ratio is obtained with intensity of oral anticoagulant treatment for an INR of 2-3, even in the elderly. Given the risks of anticoagulant therapy, including bleeding, individual thromboembolic risk must be assessed in patients with AF. In 2009, dabigatran was shown to be a reasonable alternative to vitamin K antagonists, establishing itself as a major alternative to warfarin in AF patients. Rivaroxaban and apixaban have subsequently also been shown to be alternatives to warfarin. When there are contraindications to vitamin K antagonists, antiplatelet agents can produce a therapeutic effect, although much less than oral anticoagulants. Apixaban may be a better alternative to aspirin in this setting. Patients with low-risk atrial fibrillation (no risk factors) have not been the subjects of specific clinical trials. It is unclear what would be the best therapeutic choice for these patients.
authors.affiliation: Faculdade de Medicina, Universidade do Porto, Porto, Portugal.
authors.forename: Susana P D
authors.initials: SP
authors.lastname: Sá
authors.forename: Rui P
authors.initials: RP
authors.lastname: Rodrigues
authors.forename: João
authors.initials: J
authors.lastname: Santos-Antunes
authors.forename: Francisco
authors.initials: F
authors.lastname: Rocha Gonçalves
authors.forename: José Pedro L
authors.initials: JP
authors.lastname: Nunes
mesh_terms: D001281:Atrial Fibrillation / Q000188:drug therapy*; D005343:Fibrinolytic Agents / Q000627:therapeutic use*; D006801:Humans
chemical_list: D005343:Fibrinolytic Agents