Comprehensive Assessment of Mitral Valve Geometry and Cardiac Remodeling With 3-Dimensional Echocardiography After Percutaneous Mitral Valve Repair
MitraClip is a validated treatment for significant mitral regurgitation (MR) in high risk patients. Aims of the study were to evaluate immediate changes in mitral valve (MV) geometry induced by MitraClip and correlations between baseline geometry and cardiac remodeling. Eighty patients undergoing MitraClip for primary (48%) or secondary (52%) MR were enrolled. Intraoperative transesophageal echocardiographic 3D images were acquired immediately before and after the procedure for MV annulus (MVA) morphology analysis. Transthoracic 3D echocardiography was performed pre-operatively and at 6 months follow-up (6MFU). Patients were classified on the basis of MR reduction (ΔMR) at 6MFU as Optimal (ΔMR≥2) or Suboptimal (ΔMR<2). An optimal result was reached in 60 (75%) patients, whereas 20 subjects showed a ΔMR<2 at 6MFU. The Optimal showed significantly smaller baseline MVA (antero-posterior diameter 4.05±0.59 vs. 4.43±0.68cm; anterolateral-posteromedial diameter 4.38±0.56 vs. 4.70±0.73cm; MVA circumference 14.1±1.7 vs. 15.1±2.3cm and 3D area 14.8±3.9 vs. 17.4±5.3cm2), lower sphericity index and non-planar angle compared to Suboptimal. A value of antero-posterior diameter ≥4.44 cm was identified (ROC curve) as a possible cut-off for pre-operative identification of Suboptimal patients. Post-operatively, MitraClip reduced MVA flattening (non-planar angle), sphericity index and size (as expressed by antero-posterior diameter, MVA circumference and area). At 6MFU the Optimal showed significant decrease in left ventricular volumes and pulmonary artery systolic pressure. In conclusion, MitraClip induces remarkable changes in MVA geometry and favorable LV remodeling is detected in patients with optimal mid-term outcome. A pre-procedural antero-posterior diameter <4.44cm seems to be a potential predictor of mid-term optimal result.