Atrial Functional Mitral Regurgitation
From Mitral Annulus Dilatation to Insufficient Leaflet Remodeling
This article requires a subscription to view the full text. If you have a subscription you may use the login form below to view the article. Access to this article can also be purchased.
Atrial fibrillation (AF) is the most frequent heart rhythm disorder. The estimated prevalence of AF in the United States in 2010 ranged between 2.7 and 6.1 million and is projected to increase to 12.1 million by 2030.1 Similar figures have been described in Europe: the estimated prevalence of AF in adults >55 years was 8.8 million in 2010 and projections estimate a prevalence of 17.9 million by 2060.2 The vast majority of research has focused on the most feared complications of AF: stroke, heart failure, sudden cardiac death, and noncardiovascular death. However, the occurrence of mitral regurgitation (MR) in patients with AF has received much less attention.
See Article by Kagiyama et al
MR is the most frequent valvular heart disease and is a known risk factor for AF.1 However, the prevalence and pathophysiology of MR among patients with AF remains unexplored. Between 14% and 26.4% of the patients included in landmark clinical trials on direct oral anticoagulants showed significant valvular heart disease other than moderate and severe mitral stenosis or mechanical valve prostheses.3 The most frequent valvular heart disease was MR with prevalence ranging between 73% to almost 90%.3 However, no data on the mechanism of MR were provided.
MR is classified as primary (organic), when the mitral leaflets or the subvalvular apparatus are structurally abnormal causing leaflet malcoaptation, or secondary (functional) when the leaflets and subvalvular apparatus are normal and leaflet malcoaptation is caused by global or regional left ventricular (LV) remodeling that displace the papillary muscles, tethering the mitral leaflets, or by reduction of LV closing forces. Depending on the severity and chronicity of MR, the left atrium (LA) dilates in response to the volume overload. This remodeling process involves the posterior part of the mitral annulus, causing dilatation of the mitral …