Defining nonvalvular atrial fibrillation: A quest for clarification

Abstract

Non-vitamin K oral anticoagulants (NOACs) are currently recommended for patients with nonvalvular atrial fibrillation since the publication of the 4 major pivotal trials evaluating the efficacy and safety of factor IIa and factor Xa inhibitors. The definition of nonvalvular atrial fibrillation is unclear, varying from one trial to another and even between North American and European guidelines, which is a source of uncertainties in clinical practice. However, many patients with atrial fibrillation present signs of valvular involvement, and clarification of this term is needed to not deny NOACs to patients based on the wrong perception that they may have valvular atrial fibrillation. The currently unique contraindications to NOACs are patients with mechanical heart valves and those with moderate-to-severe mitral stenosis, as stated by the recent 2015 position paper of the European Heart Rhythm Association. Patients with native heart valve involvement, regardless of their severity, are suitable for NOAC therapy. Patients with bioprosthetic heart valves and mitral valve repair may be suitable for NOACs except for the first 3 and the first 3-6 months postoperatively, respectively. Patients with transaortic valve implantation or percutaneous transluminal aortic valvuloplasty are also considered as being eligible for NOACs, although the bleeding risk has to be carefully considered in this population often requiring a combination with antiplatelet therapy. Future studies are warranted to increase the level of evidence of use of NOACs, particularly in patients with transaortic valve implantation and valvular surgery, and to determine whether they could be used in the future in the only 2 remaining contraindications.

Use of Direct Oral Anticoagulants in Canadian Primary Care Practice 2010–2015: A Cohort Study From the Canadian Primary Care Sentinel Surveillance Network

“…First, we chose to exclude AF patients with any valvular heart disease documented by their attending physician. We acknowledge that the definition of valvular disease in the setting of AF has evolved over time, and new guidelines restrict valvular AF to that associated with prosthetic mechanical valves or hemodynamically significant mitral stenosis (meaning that some patients whom we classified as having valvular heart disease would in fact meet newer definitions of nonvalvular AF) 9. However, we used a broader definition in this study because the severity of valvular disease was not well documented in the EMRs, and we were collecting data from as far back as 2010, when older definitions of valvular AF were in place.…”

“…We acknowledge that the definition of valvular disease in the setting of AF has evolved over time, and new guidelines restrict valvular AF to that associated with prosthetic mechanical valves or hemodynamically significant mitral stenosis (meaning that some patients whom we classified as having valvular heart disease would in fact meet newer definitions of nonvalvular AF). 9 However, we used a broader definition in this study because the severity of valvular disease was not well documented in the EMRs, and we were collecting data from as far back as 2010, when older definitions of valvular AF were in place. Moreover, in light of emerging evidence that patients with nonprosthetic valvular AF may still derive benefits from these agents, 10 we felt that DOACs may not necessarily be inappropriate in these cases.…”

Non‐vitamin K oral anticoagulants versus warfarin for left atrial appendage thrombus resolution in nonvalvular atrial fibrillation or flutter

“…TEE studies performed between January 2011 and December 2017 were reviewed to identify subjects that met the following criteria: 1) nonvalvular AF or flutter; 2) LA thrombus on TEE; 3) absence of prior long‐term OAC use at the time of initial LA thrombus diagnosis, defined as less than 7 days; and 4) a period between initial and closest follow‐up TEE of at least 3 weeks to less than 1 year. We used the definition of nonvalvular AF or flutter phenotype proposed by Martins et al as subjects with milder valve disease who are NOAC eligible may still be considered ‘nonvalvular’ . Therefore, subjects with mechanical valves and moderate‐to‐severe mitral stenosis were excluded, but other valvular conditions were included (i.e., bioprosthetic valve, transcatheter aortic valve replacement, mitral valve repair, etc.).…”

Oral anticoagulation and left atrial thrombi resolution in nonrheumatic atrial fibrillation or flutter: A systematic review and meta‐analysis

“…We elected to focus our study on “nonrheumatic” AF. “Nonvalvular” was avoided due to general lack of agreement on the definition, evolving definitions in guidelines, and recent suggestion that it should cease to be used altogether . Articles that included subjects exclusively with rheumatic valve disease were excluded.…”