Mitral complex geometric changes aggravate mitral stenosis after transcatheter aortic valve replacement

Severe aortic valve stenosis (AS) often coexists with mitral valve stenosis (MS). MS aggravation after transcatheter aortic valve replacement (TAVR) is common, and its etiology is multifactorial. We hypothesized that geometric changes in the mitral complex (mitral valvular and annular deformities) are adjunctive factors aggravating MS after TAVR, particularly in older adults with a smaller left ventricle (LV). This study aimed to evaluate the mitral complex geometric changes before and after TAVR and to assess the important predictors of MS aggravation after TAVR. This retrospective study enrolled consecutive adult patients who underwent TAVR and surgical AVR (SAVR) for severe AS. The mitral valve area (MVA), the angle between the anterior mitral valve leaflet (AMVL) and left ventricular outflow tract (LVOT), AMVL length, mitral annular diameter, presence of mitral annular calcification, and LV size were evaluated using transthoracic echocardiography. This study included 258 patients who underwent TAVR and SAVR. MVA index decreased from 2.3 ± 0.6 cm² to 1.9 ± 0.5 cm² in the TAVR group. The angle between the AMVL and LVOT was 56.3 ± 9.7° preoperatively and increased to 67.3 ± 11.5° after TAVR. In multivariate analysis, the most important predictive factors of MS aggravation after TAVR were a smaller mitral annular diameter, restricted AMVL mobility, and implantation depth (odds ratio: 4.5, 5.3,3.0; 95% confidence interval: 1.6-14, 1.9-17, 1.0-8.9; and p = 0.005, p = 0.001, p = 0.042, respectively). The reduction in MVA after TAVR was related to the restriction of AMVL opening, depth of implantation and narrowing of the mitral annulus.