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 reported previously.

METHODS

We conducted an observational study of 1191 patients from 11 Canadian centres undergoing M-TEER with a MitraClip device (Abbott, location). M-TEER databases from each centre were collected centrally and merged into a single Canada-wide database. The primary outcome was MR severity before M-TEER vs at up to 1 year after M-TEER. Secondary outcomes included hospitalizations for heart failure (HF) and New York Heart Association (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 vs 11.0% at up to 1 year after M-TEER (absolute risk difference [ARD] 86.4%, < 0.001). Hospitalization for HF occurred in 50.7% before vs 10.3% at up to 1 year after M-TEER (ARD 40.4%, < 0.001), with similar benefit in patients with functional (ARD 44.8%, 95% confidence interval 39.5-50.1) and degenerative (ARD 34.8%, 95% confidence interval 29.0-40.6) MR. NYHA class III-IV HF was present in 82.8% before vs in 16.6% at up to 1 year after M-TEER (ARD 66.2%, < 0.001). Single-leaflet detachment (1.0%) and mitral valve surgery (2.2%) were infrequent. Mortality was 1.3% in-hospital, and 12.7% at 1 year.

CONCLUSIONS

In this first national registry of patients undergoing M-TEER in Canada, M-TEER resulted in a sustained reduction in MR and was associated with reduced HF hospitalizations and improvement in NYHA functional class, with a high degree of safety. This benefit was consistent in patients with functional and degenerative MR.