Related Experiment Video
Updated: May 27, 2026
Catheter Ablation in Combination With Left Atrial Appendage Closure for Atrial Fibrillation
Published on: February 26, 2013
Antithrombotic therapy in nonvalvular atrial fibrillation: a narrative review
Susana P D Sá1, Rui P Rodrigues, João Santos-Antunes
1Faculdade de Medicina, Universidade do Porto, Porto, Portugal.
Insights
Oral anticoagulants significantly reduce stroke risk in atrial fibrillation (AF). Newer drugs like dabigatran, rivaroxaban, and apixaban offer alternatives to warfarin, but optimal treatment for low-risk AF remains unclear.
Area of Science:
- Cardiology
- Neurology
- Pharmacology
Background:
- Atrial fibrillation (AF) is a significant, modifiable stroke risk factor.
- Oral anticoagulants, like warfarin, have been proven effective in reducing AF-related strokes since 1989.
- Optimal anticoagulation intensity (INR 2-3) balances risks and benefits, even in elderly patients.
Purpose of the Study:
- To review the efficacy and alternatives to warfarin for stroke prevention in atrial fibrillation.
- To discuss the role of newer oral anticoagulants and antiplatelet agents.
- To highlight the uncertainty in optimal treatment for low-risk AF patients.
Main Methods:
- Review of established and emerging anticoagulant therapies for AF.
- Comparison of vitamin K antagonists (VKAs) with newer oral anticoagulants (NOACs) and antiplatelet agents.
- Assessment of risk-benefit profiles for stroke prevention in AF.
Main Results:
- Warfarin, with an INR of 2-3, provides a significant reduction in AF-related stroke.
- Dabigatran, rivaroxaban, and apixaban are established alternatives to warfarin.
- Apixaban may be superior to aspirin when VKAs are contraindicated.
- The best therapeutic strategy for low-risk AF patients is not yet defined.
Conclusions:
- Effective stroke prevention in AF relies on assessing individual thromboembolic risk.
- NOACs offer viable alternatives to warfarin for many AF patients.
- Further research is needed to determine optimal stroke prevention strategies for low-risk AF populations.
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.
Related Concept Videos
01:29Venous Thrombosis III: Interprofessional Care
01:30Anticoagulant Drugs: Low-Molecular-Weight Heparins
01:18Anticoagulant Drugs: Vitamin K Antagonists and Direct Oral Anticoagulants
Warfarin, a prominent vitamin K antagonist family member, exerts its effect by inhibiting the enzyme VKORC1 (vitamin K epoxide reductase complex 1). By hindering this enzyme, warfarin...
01:20Antiplatelet Drugs: Prostaglandin Synthesis, P2Y12 and Glycoprotein IIb/IIIa Inhibitors
Prostaglandin synthesis inhibitors, exemplified by the widely known aspirin, wield their power by irreversibly acetylating...
01:25Dysrhythmias VI: Management of Dysrhythmias
01:26Angina IV: Management