Annular Geometry in Patients With Chronic Ischemic Mitral Regurgitation

Abstract

Background— Although animal studies showed that annular remodeling may be related to the pathogenesis of chronic ischemic mitral regurgitation (CIMR), little was known in humans. A better understanding of the precise 3D geometry of the mitral valvular-ventricular complex in CIMR is needed to devise a better surgical technique. The purpose of the study was to elucidate mitral annular geometry in patients with CIMR using cardiac MRI. Methods and Results— Thirty-eight patients with previous inferior or posterior myocardial infarction were studied. With the 3D reconstruction of the mitral annulus and subvalvular apparatus from a series of longitudinal cine MRIs, end-systolic mitral annulus dimensions and 3D geometry were calculated. Patients were grouped by mitral regurgitation grade using echocardiography (≥2+, n=15 versus ≤1+, n=23). Both septal-lateral and commissure-commissure mitral annular diameters were significantly greater in CIMR(+) patients (35±5 versus 30±4 mm, P =0.005; 46±6 versus 39±4 mm, P <0.001, respectively). The length of the fibrous annulus was significantly larger in CIMR(+) patients (28±3 versus 24±3 mm; P <0.001). The height of the annular “saddle horn” above a best-fit plane was lower in CIMR(+) patients (4.2±1.2 versus 6.0±1.8 mm; P =0.002), and the annular height to commissural width ratio was significantly lower in CIMR(+) patients (12±3 versus 21±5%; P <0.001). Conclusions— Patients with CIMR had greater septal-lateral and commissure-commissure mitral annular dimension, larger intertrigonal distance, and flattened saddle shape of mitral annulus. These associated geometric alterations may be important in the pathogenesis of CIMR.

Clinical, functional and prognostic implications of severe atrial dilation in secondary mitral regurgitation

“…Our findings support an additive effect whereby the leaflets are tethered by the ventricular component but to a lesser extent due to the atrial component. While annular dilation is a key component of both ASMR and VSMR,3 25 26 our study shows that SADMR is associated with an even greater annular dilation.…”

The Role of Cardiovascular Magnetic Resonance Imaging in the Assessment of Mitral Regurgitation

“…It can aid in the diagnostic work-up of various dilated cardiomyopathies, and it can also detect the extent of fibrosis and provide valuable information regarding revascularization and a concurrent mitral valve surgery in patients who are surgical candidates [ 71 , 72 ]. With its high spatial resolution and endocardial delineation, it can reliably assess LV remodelling and accurately quantify alterations in annular geometry, including septal–lateral and inter-commissural diameters, even when compared to the excellent resolution of transoesophageal echocardiography [ 73 ]. Such detailed assessments can guide surgical or percutaneous reparative approaches and monitor their outcome and long-term LV remodelling without the need for more invasive modalities and their associated risks [ 52 ].…”