Relation of Mitral Annulus and Left Atrial Dysfunction to the Severity of Functional Mitral Regurgitation in Patients with Dilated Cardiomyopathy

Abstract

<jats:p><jats:italic>Introduction and Objectives</jats:italic>. Patients with dilated cardiomyopathy (DCM) and functional mitral regurgitation (FMR) present altered geometry and dynamics of the mitral annulus (MA). We aimed to further assess the relationship between the MA dysfunction, FMR severity, and LA dysfunction in patients with ischemic and nonischemic DCM by using three-dimensional transthoracic echocardiography (3DTTE). <jats:italic>Methods</jats:italic>. 56 patients (58 ± 17 years, 42 men) with DCM and FMR and 52 controls, prospectively enrolled, underwent 3DTTE dedicated for mitral valve (MV), LA, and left ventricle (LV) quantitative analysis. <jats:italic>Results</jats:italic>. Patients with FMR vs. controls presented increased MA size and sphericity during the entire systole, whereas MA fractional area change (MAFAC) and MA displacement were decreased (15 ± 5 vs. 28 ± 5%; and 5 ± 3 vs. 10 ± 2 mm, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mi>p</mml:mi><mml:mo>&lt;</mml:mo><mml:mn>0.001</mml:mn></mml:math>). In patients with moderate/severe FMR, MA diameters correlated with PISA radius, EROA, and regurgitant volume (Rvol), as also did the MA area (with PISA radius, EROA, and Rvol: <jats:italic>r</jats:italic> = 0.48, <jats:italic>r</jats:italic> = 0.58, and <jats:italic>r</jats:italic> = 0.47, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M2"><mml:mi>p</mml:mi><mml:mo>&lt;</mml:mo><mml:mn>0.05</mml:mn></mml:math>). MAFAC correlated inversely with EROA and Rvol (<jats:italic>r</jats:italic> = −0.32 and <jats:italic>r</jats:italic> = −0.35, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M3"><mml:mi>p</mml:mi><mml:mo>&lt;</mml:mo><mml:mn>0.05</mml:mn></mml:math>), with both active and total LA emptying fractions and with LV ejection fraction as well. In a stepwise multivariate regression model, decreased MAFAC and increased LA volume independently predicted patients with severe FMR. <jats:italic>Conclusions</jats:italic>. Patients with DCM and FMR have MA geometry remodeling and contractile dysfunction, correlated with the severity of FMR. MA contractile dysfunction correlated with both LA and left LV pumps dysfunctions and predicted patients with severe FMR. Our results provide new insights that might help with better selection of patients for MV transcatheter procedures.</jats:p>

Left Atrial Volume Correlates with Mitral Annulus Size: An MDCT Study

“…In the patients with no-to-mild mitral regurgitation, compared to moderate-to-severe mitral regurgitation, the mitral annulus dimensions were lower, as follows: a transversal diameter of 32.0 vs. 32.9 mm; a longitudinal diameter of 38.3 vs. 41.0 mm; an MV area of 9.58 vs. 12.66 cm 2 ; a circumference of 11.5 vs. 13.4 cm [12]. The following similar results were obtained by Mihaila Baldea et al [13], using three-dimensional transthoracic echocardiography: The MA transverse diameter was 34 mm for patients with functional mitral regurgitation and 28 mm in control subjects. The longitudinal diameter was 44 mm in patients with functional MR and 39 mm in control subjects, whilst the circumference was 12.9 mm and 11.2 mm, respectively.…”

The Impact of Atrial Fibrillation on All Heart Chambers Remodeling and Function in Patients with Dilated Cardiomyopathy—A Two- and Three-Dimensional Echocardiography Study

“…In DCM, functional mitral regurgitation (FMR) occurs due to an imbalance between tethering forces, which are increased (LV global dilation, papillary muscles displacement), and closing forces (reduced LV contractility, asynchronous contraction) in the presence of a structurally normal valve. This imbalance is influenced by the dynamics and dimensions of the mitral annulus (MA) [ 18 , 19 ]. The presence of AF can further modify this complex interplay.…”