Quantification of mitral regurgitation by real time three-dimensional color Doppler flow echocardiography pre- and post-percutaneous mitral valve repair.

BACKGROUND: Echocardiographic quantification of mitral regurgitation (MR) can be challenging if the valve geometry is significantly altered. Our aim was to compare the quantification of MR by the recently developed real time three-dimensional (3D) volume color flow Doppler (RT-VCFD) method to the conventional two-dimensional (2D) echocardiographic methods during the MitraClip procedure.

METHODS: Twenty-seven patients (mean age 76 ± 8 years, 56% male) were prospectively enrolled and severity of MR was assessed before and after the MitraClip procedure in the operating room by 3 different methods: (1) by integrative visual approach by transesophageal echocardiography, (2) by transthoracic 2D pulsed-wave Doppler-based calculation of aortic stroke volumes (SV) and mitral inflow allowing calculation of regurgitant volume, and (3) by transthoracic 3D RT-VCFD-based calculation of regurgitant volume.

RESULTS: We found moderate agreement between the integrative visual approach and the 3D RT-VCFD method for assessment of MR severity before (κ = 0.4, P < 0.05) and after MitraClip (κ = 0.5, P < 0.05). Relevant MR (3+ and 4+) was detected by visual approach in 27/27 and by 3D-VCFD method in 24/27 patients before and in 1 patient by both methods after the MitraClip procedure. In contrast, MR quantification by 2D SV method did not agree with the integrative visual approach or with the 3D RT-VCFD method.

CONCLUSIONS: Quantification of MR before and after percutaneous MV repair by 3D RT-VCFD is comparable to the integrative visual assessment and more reliable than the 2D SV method in this small study population. Further automation of 3D RT-VCFD is needed to improve the accuracy of peri-interventional MR quantification.