Trials comparing coumadin (vitamin K antagonists or VKA) with DOACS (Direct oral anticoagulants) in atrial fibrillation (AF) were done only in patients with so-called ‘non-valvular’ AF. Patients with ‘valvular AF’ were excluded.
The distinction between ‘valvular’ and ‘non-valvular’ AF remains a matter of debate.
What is valvular atrial fibrillation?
Currently, ‘valvular AF’ refers to patients with mitral stenosis or artificial heart valves (and valve repair in North American guidelines only).
Valvular AF should be treated with coumadin or VKAs.
Patients with “non-valvular AF” may have other types of valvular heart disease, as you will see below. It’s important to emphasize that “non-valvular AF” does not exclude patients with some types of valvular heart disease from therapy with DOACs.
What is Non-Valvular Atrial Fibrillation?
” Valvular heart diseases, such as mitral regurgitation, aortic stenosis (AS) and aortic insufficiency, do not result in conditions of low flow in the left atrium, and do not apparently increase the risk of thromboembolism brought by AF. ” These conditions aren’t included in the definition of ‘valvular atrial fibrillation’. They are treated just like non-valvular atrial fibrillation. DOACS are fine for them.
Non-valvular atrial fibrillation obviously includes atrial fibrillation in patients with normal valvular function as well as those with valvular defects that do not result in conditions of low flow in the left atrium and do not increase the risk of VTE brought by AF.
Other Times when Coumadin is preferred over the DOACS
Patients with mechanical prosthetic valve should be treated with Coumadin.
Further Reading
Arch Cardiovasc Dis. 2015 Oct;108(10):530-9. How to define valvular atrial fibrillation?