Choice of anticoagulant to prevent thromboembolic events in atrial fibrillation
A direct-acting oral anticoagulant (DOAC) (eg apixaban, rivaroxaban, dabigatran) or warfarin is used to prevent thromboembolic events in atrial fibrillation.
Patients with atrial fibrillation who have rheumatic mitral stenosis and/or a mechanical heart valve1 have a particularly increased thromboembolic risk and require anticoagulant therapy. Treat these patients with warfarin. At the time of writing, apixaban has not been studied in these patients. Rivaroxaban has shown inferiority to warfarin in patients with rheumatic heart disease and atrial fibrillationConnolly, 2022. Dabigatran has shown inferiority to warfarin in patients with a mechanical heart valve or undergoing mechanical heart valve replacement Eikelboom, 2013. For more information, see Warfarin to prevent thromboembolic events in atrial fibrillation.
If anticoagulant therapy is indicated, DOACs are preferred over warfarin for all other patients with atrial fibrillation (including those with other valvular heart disease, such as mitral regurgitation or bioprosthetic valves)Hindricks, 2021. DOACs have comparable efficacy to warfarin and a lower risk of major bleeding2Connolly, 2009Giugliano, 2013Granger, 2011Patel, Mahaffey, Garg, Pan, Singer, Hacke, Breithardt, Halperin, Hankey, Piccini, Becker, Nessel, Paolini, Berkowitz, Fox, Califf, , 2011. For more information, see Direct-acting oral anticoagulants to prevent thromboembolic events in atrial fibrillation.
Antiplatelet drugs, including aspirin or P2Y12 inhibitors (clopidogrel, prasugrel, ticagrelor), are not recommended to prevent thromboembolic events or stroke in patients with atrial fibrillation. Oral anticoagulation with warfarin or DOAC therapy is more effective than single or dual antiplatelet therapy, and increases the bleeding risk less than dual antiplatelet therapyBen Freedman, 2015Hindricks, 2021.
For patients with atrial fibrillation and an indication for dual antiplatelet therapy (eg acute coronary syndrome), triple antithrombotic therapy (an oral anticoagulant, aspirin and a P2Y12 inhibitor) can be used. It is typically only continued for a short period before one of the antiplatelet drugs is stopped. The patient’s specialist will determine whether to start and when to stop each drug. See Combined anticoagulant and antiplatelet therapy for long-term management of acute coronary syndromes for more information on combining anticoagulants and antiplatelet drugs.