Use of Non-vitamin K Antagonist Oral Anticoagulants (NOAC) for Stroke Prevention in Patients with Atrial Fibrillation and Underlying Valvular Heart Disease A Systematic Review

Background: Non-vitamin K antagonist oral anticoagulants (NOACs) are commonly used for stroke prophylaxis in patients with atrial fibrillation (AF), but their efficacy and safety in patients with underlying valvular heart disease (VHD) is unknown. Methods: A search of MEDLINE, CENTRAL, Embase, clinicaltrials.gov was performed with the terms direct oral antiocoagulants, new oral anticoagulants, DOAC, NOAC, rivaroxaban, apixaban, dabigatran, valvular heart disease, aortic stenosis, aortic regurgitation, mitral regurgitation, tricuspid stenosis, tricuspid regurgitation, pulmonary stenosis and pulmonary regurgitation. Only clinical studies with clinical endpoints that compared NOACs with warfarin in patients with AF and identified VHD were included. Results: Four clinical studies were retrieved based on our search criteria. Subgroup analysis of the landmark trials comparing a NOAC to warfarin in AF patients with underlying VHD demonstrated that NOACs had similar or superior efficacy in stroke prevention compared to warfarin. The risk bleeding with NOACs compared to warfarin in these patients yielded inconsistent results. Conclusion: Based on the available evidence, NOACs provide similar or superior stroke reduction compared to warfarin in patients with AF and VHD, especially in aortic valve disease and mitral regurgitation. The rate of major bleeding between NOACs and warfarin in this patient population is unclear. Keywords: Non-vitamin K antagonist oral anticoagulants; Heart disease; Atrial fibrillation; Mitral regurgitation; Tricuspid regurgitatio