RESUMO
BACKGROUND: Transcatheter edge-to-edge mitral valve repair may lead to a reduction in mitral valve area (MVA) and elevated mean transmitral gradient (TMG). The objectives of this study were to assess the value of baseline MVA by different imaging methods and to explore the associations between MVA indexed to body surface area or left ventricular forward stroke volume and postprocedural TMG. METHODS: Preprocedural echocardiographic images from 76 consecutive patients were retrospectively reviewed. MVA planimetry from two-dimensional (2D) transthoracic echocardiography (MVATTE), 2D transesophageal echocardiography in the transgastric view (MVA2D TEE), and three-dimensional (3D) transesophageal echocardiography (MVA3D) were measured. Postprocedural TMGs were assessed at 1 to 3 months and all-cause mortality at 1 year. RESULTS: Postprocedural mean TMG > 5 mm Hg was associated with a 3.42-fold (95% confidence interval [CI], 1.08-10.87; P = .04) increased risk for 1-year all-cause mortality. Patients with postprocedural TMG > 5 mm Hg (25% [19 of 76]) had significantly smaller preprocedural MVA3D (3.9 ± 0.8 vs 5.2 ± 1.3 cm2, P < .01) and MVATTE (4.9 ± 1.1 vs 5.8 ± 1.5 cm2, P = .01) compared with patients without elevated TMG. No significant difference was found for MVA2D TEE (P = .20). The best threshold values for MVA3D and MVATTE to be associated with postprocedural TMG > 5 mm Hg were, respectively, 3.9 cm2 (area under the curve [AUC] = 0.80; 95% CI, 0.66-0.94; sensitivity 62%, specificity 87%) and 4.6 cm2 (AUC = 0.68; 95% CI, 0.54-0.82; sensitivity 53%, specificity 80%). MVA3D indexed to body surface area and to stroke volume showed overall the best associations with postprocedural mean TMG > 5 mm Hg, with optimal thresholds, respectively, of 2.5 cm2/m2 (AUC = 0.88; 95% CI, 0.77-0.98; sensitivity 92%, specificity 74%) and 95 cm2/L (AUC = 0.87; 95% CI, 0.77-0.97; sensitivity 85%, specificity 82%). CONCLUSIONS: Elevated TMG following transcatheter edge-to-edge mitral valve repair was associated with increased mortality. The present results indicate that MVA3D, MVA3D indexed to body surface area, and MVA3D indexed to stroke volume may be considered potential predictors of postprocedural TMG > 5 mm Hg and could help optimize patient selection, while the use of 2D methods for valve area were poorly associated with TMG.
