Efficacy and Safety of Transcatheter Mitral Valve Edge-to-Edge Repair with a MitraClip Device in Real-World Canadian Practice

BACKGROUND Mitral transcatheter edge-to-edge repair (M-TEER) is a treatment option for patients with symptomatic mitral regurgitation (MR). The real-world experience with M-TEER in Canada has not been previously reported. METHODS We conducted an observational study of 1,191 patients from 11 Canadian centers undergoing M-TEER with MitraClip. M-TEER databases from each center were centrally collected and merged into a single Canada-wide database. The primary outcome was MR severity before M-TEER versus up to 1-year after M-TEER. Secondary outcomes included hospitalizations for heart failure (HHF) and NYHA functional class. RESULTS MR etiology was degenerative in 41% and functional in 59%. The mean age was 76 years and 36% were women. The proportion with MR ≥ 3+ was 97.3% before versus 11.0% up to 1-year after M-TEER (absolute risk difference [ARD] 86.4%, P<0.001). HHF occurred in 50.7% before versus 10.3% up to 1-year after M-TEER (ARD 40.4%, P<0.001), with similar benefit in patients with functional (ARD 44.8%, 95% CI 39.5-50.1) and degenerative (ARD 34.8%, 95% CI 29.0-40.6) MR. NYHA class III-IV HF was present in 82.8% before versus 16.6% up to 1-year after M-TEER (ARD 66.2%, P<0.001). Single-leaflet detachment (1.0%) MV surgery (2.2%) were infrequent. Mortality was 1.3% in-hospital and 12.7% at 1-year. CONCLUSION In this first national registry of M-TEER in Canada, M-TEER resulted in a sustained reduction in MR and was associated with reduced heart failure hospitalizations and improvement in NYHA functional class, with a high degree of safety. This benefit was consistent in patients with functional and degenerative MR.