Introduction: Transcatheter mitral valve repair utili-zing a MitraClip (MC) system is the most frequent in-terventional option for the severe mitral regurgitation (MR) treatment. It is known that MC procedure redu-ces mitral regurgitation thus improving the symptoms, while its impact on the annulus morphology remains unclear. Even if the 3D echocardiography is the most accurate method of periprocedural valvular assess-ment, its interpretation and processing often require more time than the 2D measurement while the rela-tionship between 2D and 3D assessment is unknown.
Objective: To assess mitral valve annular geometry ri-ght before and immediately after MC implantation, but also the relationship between 2D and 3D echocardio-graphy evaluation of the mitral annulus.
Methods: An off-line analyse of the mitral valve mor-phology and regurgitation mechanism was made using 2D and 3D full volume data sets, which were assessed by transesophageal echocardiography, before and imme-diately after clip implantation in consecutive patients with symptomatic severe mitral regurgitation who underwent MC procedure. The 2D analysis comprises the regurgitation mechanism and the measurement of the antero-posterior diameter (APD) of the mitral annulus (MA). By 3D acquisition were evaluated the regurgita-tion mechanism, the APD, the annulus area (AA) and its circumference (AC).
Results: We included 31 patients (70±11 years, 83.9% men) at high surgical. The procedure was successful-ly completed in all patients, with mild residual MR in 24 (77.4%) and mild to moderate (grade II/IV) in 7 (22.6%). All patients had final transvalvular mean gra-dient less than 5 mmHg. 25 (80.6%) patients had se-condary MR, and 6 (19.4) of them primary MR. The clip location for 27 (87.1%) was central (A2/P2 mitral scallops) while the rest required lateral implantation: A1/P1 in 1 (3.2%) subject and A3/P3 in 3 (9.7) of them. 19 (61.3%) of patients needed 1 clip, while 11 (35.5%) were treated with 2 clips and 1 (3.2%) with 3 clips. In 2D analysis was observed a reduction in the APD of the MA from 35±0.93 mm to 29±0.90 (p<0.001) mm after MC. Also in 3D assessment the APD of the MV decreased from 31±0.81 mm to 25±0.82, (p<0.001). In 3D analysis both AA and AC had similar values before and after MC, with a minimal reduction: from 10±0.48 cm² to 9.2±0.44 cm² for AA and from 12±0.29 cm to 11.4±0.27 cm for AC both with p<0.001. The APD of the MV annulus was significantly correlated between 2D and 3D analysis with r=0.857 (p<0.001) before MC, r=0.789, (p<0.001) after the procedure.
Conclusions: MC procedure impacts the MA geome-try by reducing the APD without modifying signifi-cantly the AA and the AC, having successful results in reducing the MR of any cause. More than that there is a strong correlation between 2D and 3D MA analysis, thus being easier to evaluate periprocedural the valvu-lar morphology. Further studies are needed to confirm the stability in MV geometry changes and also the rela-tion between 2D and 3D assessment.