Evaluation of three-dimensional right ventricular function and reverse remodelling in patients undergoing percutaneous mitral valve repair for functional mitral regurgitation: insights from a multicentre Italian registry

Background: The predictive role of right ventricular dysfunction (RVD) in patients with functional mitral regurgitation (FMR) undergoing transcatheter edge-to-edge repair (TEER), as well as RV remodelling following the procedure, remains uncertain. We evaluated the prognostic impact of pre-procedural three-dimensional (3D) right ventricular ejection fraction (RVEF) in patients with FMR. Additionally, we assessed the RV reverse remodelling (RVRR) based on 3D volumes and ejection fraction six months after the procedure. Methods: Data from 74 patients treated with TEER for FMR were prospectively collected. Pre-procedural RVD, defined as 3D RVEF ≤45%, was observed in 47 patients (63.5%). Patients were divided into three groups according to pre-procedural 3D-RVEF: no RVD (No-RVD, RVEF >45%, n = 27), mild-to-moderate RVD (MRVD, RVEF 31-45%, n = 36), and severe RVD (SRVD, RVEF ≤30%, n = 11). Results: Patients with SRVD demonstrated a significant higher rate of all-cause mortality compared with the other two groups (p = 0.04) and RVEF ≤ 30% was associated with all-cause death, independently of left ventricular ejection fraction (LVEF) and left atrial volume index (LAVi) (HR: 3.72, 95% CI 1.12–12.30, p = 0.03). At 6-month follow-up, only patients with pre-procedural MRVD showed a significant reduction in 3D RV volumes and an improvement in RVEF compared to baseline (p < 0.05). Conclusions: RVD was common among patients undergoing mitral TEER for FMR. Those with pre-procedural SRVD had worse mid-term survival compared to patients with MRVD and No-RVD. The group with MRVD was the only one to demonstrate an RVRR six months after the procedure.