Novel oral anticoagulants and valvular atrial fibrillation: are they always contraindicated?

Atrial fibrillation (AF) is the most common sustained cardiac dysrhythmia, and is associated with an increased risk of death, stroke, and other thromboembolic events. Valvular heart disease (VHD) frequently coexists with AF, mostly in elderly patients. After the introduction of novel oral anticoagulants (NOACs) approved for the prevention of stroke in non-valvular atrial fibrillation (NVAF) on the basis of recent trials, the importance of a universal definition of NVAF was raised in clinical practice. In the most recent guidelines, the term valvular AF is used to imply that AF is related to rheumatic valvular disease (predominantly mitral stenosis), or prosthetic heart valves. In all the trials comparing NOACs and warfarin, a significant percentage of patients presented any type of VHD, excluding rheumatic mitral stenosis and mechanical heart valve. The subgroups analysis performed, so far showed no significant differences in terms of efficacy in the VHD subgroup compared to the general AF population. A restrictive definition of valvular AF (i.e., rheumatic mitral stenosis and mechanical heart valve) seems to be the most appropriate to contraindicate treatment with NOACs for AF thromboprophylaxis. In the remaining AF patients with significant valvular disease who per se would not require oral anticoagulation, NOACs should be allowed.