Functional mitral regurgitation: structural modifications with percutaneous valve repair with MitraClip

BACKGROUND: Mitral regurgitation (MR) is one of the most prevalent valvular diseases in our society. Transcatheter mitral valve repair (TMVR) with the MitraClip(®) system is increasingly used for treating this condition. The aim of our study is to analyse morphological mitral valve changes related to the procedure and its correlation with the degree of regurgitation at mid-term follow-up and with the combined endpoint of heart failure and all-cause mortality. METHODS: A single-centre, prospective and observational study including consecutive patients admitted between October 2015 and October 2019 for TMVR was designed. The mitral valve annulus (MVA) was analyzed using the three-dimensional MVQ QLAB mitral valve quantification software (Philips; Amsterdam, The Netherlands). Clinical data was collected retrospectively. RESULTS: Eighty-two MitraClip(®) were implanted. Control echocardiograms showed a significant decrease in the three measures: annular diameters, perimeter and area. Patients with functional MR had greater left ventricular and mitral annular dimensions and experienced greater reductions in anteroposterior diameter and mitral valve area compared with organic MR patients. The anteroposterior diameter reduction (OR 0.90; 95% CI: 0.82–0.99), as well as posterior leaflet grasping (OR 0.94; 95% CI: 0.89–0.99) were associated with the probability of significant MR recurrence. Posterior leaflet grasping and left ventricle ejection fraction were associated with the combined endpoint of heart failure and any cause death. CONCLUSIONS: MitraClip(®) implantation results in secondary changes in the mitral annular morphology. The magnitude of these morphological changes varies depending on the etiology of the mitral valve regurgitation. Posterior leaflet grasping and anteroposterior diameter reduction after clip are factors associated with relevant clinical and echocardiographic endpoints.