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

BACKGROUND: The aim of this study was to quantify the acute dynamic changes of mitral valve (MV) geometry throughout the cardiac cycle-during percutaneous MV repair with the MitraClip system by 3-dimensional transesophageal echocardiography (3D TEE).

METHODS: The MV was imaged throughout the cardiac cycle (CC) before and after the MitraClip procedure using 3D TEE in 28 patients (mean age, 77 ± 8 years) 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.

RESULTS: Percutaneous MV repair decreased anterior-posterior diameter by up to 9% (at 50% of CC; from 34.5 to 31.9 mm; 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 42.3 mm; 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 0.2 mm2 (at 0% of CC; p = 0.007), and during diastole the maximum decrease being from 4.6 to 1.6 cm2 (at 50% of CC; p < 0.001).

CONCLUSIONS: Percutaneous 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.