Changes in dynamic mitral valve geometry during percutaneous edge-edge mitral valve repair with the MitraClip system

BackgroundThe aim of this study was to quantify the acute dynamic changes of mitral valve (MV) geometry throughout the cardiac cycleduring percutaneous MV repair with the MitraClip system by 3-dimensional transesophageal echocardiography (3D TEE).MethodsThe MV was imaged throughout the cardiac cycle (CC) before and after the MitraClip procedure using 3D TEE in 28 patients (mean age, 778years) with functional mitral regurgitation (FMR). Dynamic changes in the MV annulus geometry and anatomical MV orifice area (AMVOA) were quantified using a novel semi-automated software.ResultsPercutaneous MV repair decreased anterior-posterior diameter by up to 9% (at 50% of CC; from 34.5 to 31.9mm; p<0.001) throughout the CC and increased the diastolic lateral-medial diameter by up to 7% (at 60% of the CC; from 39.7 to 42.3mm; p<0.001), whereas the annular circumference and area were not significantly affected. Annulus sphericity index was reduced up to 13% (at 50% of the CC; from 0.89 to 0.78, p<0.001). The AMVOA also decreased during systole, the maximum decrease being from 0.6 to 0.2mm(2) (at 0% of CC; p=0.007), and during diastole the maximum decrease being from 4.6 to 1.6cm(2) (at 50% of CC; p<0.001).ConclusionsPercutaneous MV repair reduces the MR by an improved coaptation of MV leaflets joint with a simultaneous indirect reduction of anterior-posterior diameter. Further, the MitraClip procedure leads to a reduction of AMVOA of more than 60% during diastole.