February 24th, 2014
What Is “Non-Valvular” Atrial Fibrillation?
Shengshou Hu, M.D.
CardioExchange welcomes this guest post from Dr. Westby Fisher, an electrophysiologist practicing at NorthShore University HealthSystem in Evanston, Illinois, and a Clinical Associate Professor of Medicine at the University of Chicago’s Pritzker School of Medicine. This piece originally appeared on his blog, Dr. Wes.
With the recent heavy marketing of the relatively new novel oral anticoagulants dabigatran, rivaroxaban, and apixaban, a new marketing phrase has been born: “non-valvular” atrial fibrillation.
What, exactly, is “non-valvular” atrial fibrillation?
Is it atrial fibrillation without any valvular heart disease like a teeny, tiny bit of functional mitral insufficiency? Or should doctors “ignore” the degree of mitral insufficiency when prescribing these medications? What about mitral-valve-prolapse patients with severe prolapse?
Is it atrial fibrillation without the presence of any prosthetic heart valve? What about a valve ring placed when a mitral valve is surgically “repaired?”
Is it atrial fibrillation without any rheumatic heart disease? What about mild mitral stenosis compared to moderate or severe mitral stenosis? If there’s a difference, what valve area should we use to judge safety of prescribing the novel oral antiocoagulants?
Or is it some combination of one or more of these above patient groups?
For doctors who manage patients with atrial fibrillation and are considering if they should offer a novel oral anticoagulant to a patient in lieu of warfarin, this issue is not a trivial question.
To answer some of these questions, we should turn to the RE-LY, Rocket AF, and Atristotle Trials. But these trials offer only minimal guidance to today’s practicing physicians.
For instance, in the RE-LY trial, only patients without “history of heart valve disorder (i.e., prosthetic valve or hemodynamically relevant valve disease)” were studied. What, exactly, do they mean by “hemodynamically relevant heart valve disease?” Does any valve qualify or just the mitral valve?
The Rocket AF trial describes their “non-valvular” heart disease patients a bit better as those with (1) hemodynamically significant mitral valve stenosis or (2) a prosthetic heart valve (annuloplasty with or without prosthetic ring, commissurotomy and/or valvuloplasty WERE permitted.) But were mild mitral stenosis patients included? What, exactly, defined “hemodynamically-significant” mitral stenosis patients?
The Aristotle trial defined their excluded valvular heart disease as patients with “moderate or severe mitral stenosis, or conditions other than atrial fibrillation that required anticoagulation (e.g., a prosthetic heart valve).” The reader must assume that surgically-repaired mitral valves were okay, but were they included or excluded from this trial – we’re not sure.
For doctors on the front line of medicine who might want to prescribe these new drugs to their patients, the term “non-valvular atrial fibrillation” seems to mean different things to different people.
Common sense would dictate that any patient with mitral stenosis (of any severity, in my opinion — be it rheumatic or post-surgical) or patients with prior placement of a prosthetic heart valve (either bioprosthetic or mechanical) should not be considered for these agents. But this is just my wild-ass guess. After all, there is no clear consensus on what really defines “non-valvular” atrial fibrillation, especially when we examine the evidence-based data available to doctors on this issue.
But beyond this, as researchers test new therapies, we should be careful not to coin confusing new marketing terms to describe a complicated constellation of patients. Otherwise, we might risk injuring those we really are trying to help.
7 Responses to “What Is “Non-Valvular” Atrial Fibrillation?”
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Yes, Wes, the terms “Non-Valvular Atrial Fibrillation” or as they say, NVAF, are ambiguous. It is pretty clear what “SPAF” stands for, but if you are talking about SPAF in the setting of “NVAF”,you are talking about therapy with warfarin. I always took “NVAF” to mean a-fib in the setting of a mechanical valve, or MS where therapy with warfarin would be otherwise indicated. I did not consider settings where you have a-fib with other forms of cardiac valve disease. I would have to use clinical judgement in cases where various degrees of valvular disease existed along with the need for pharmacologic stroke prevention.
CHADS does not take valvular disease into account when deciding to anticoagulate with the exception that most cases of significant MS should receive anticoagulation. It is an area in need of further study.
By the way, “Jabba” must be a young man with his own kids by now. How have you been doing?
In RE-LY, the main thrust of the “nonvalvular” requirement was to exclude patients with potentially operable mitral disease. My understanding is that patients with bioprosthetic valves were eligible for the trials. Moderate or more MS would exclude patients, presumbly due to the higher embolic risk, as reflected in higher INR goals. In any event, the term is poor.
Defining nonvalvular seems to be a serious subject. In patients with severe valvular calcification but hemodynamically stable (exclude MS), what can we do?
I was attending a SPAF meeting where this subject was aired
The discussion was nhat many older patients have some degree of mitral disease just be virtue of age and so the decision was that NVAF was af with serious mitral valve disease and not simple MS,
What a lout an aortic bio prosthesis patient who develops AF years after valve replacement (has only been taking ASA till that time)?
OUTCOMES OF PATIENTS WITH ATRIAL FIBRILLATION AND SIGNIFICANT VALVULAR LESIONS: COMPARISON OF THE EFFECTS OF RIVAROXABAN AND WARFARIN IN THE ROCKET AF TRIAL
A total of 1992 (14 %) patients had SVD, often with combined lesions
89.6% mitral regurgitation +/- aor tic stenosis or regurgitation
I agree there is no clear definition, the consensus is that any bioprosthetic or mechanical valve and moderate or severe MS are valvular afib and require warfarin, although I have seen pts post TAVR afib who were placed off label on the novel anticoagulants as well.