MP-2 - EFFICACY AND SAFETY OF TRANSCATHETER MITRAL VALVE EDGE-TO-EDGE REPAIR IN REAL-WORLD CANADIAN PRACTICE: THE PREMISE REGISTRY

Background: Transcatheter mitral valve edge-to-edge repair (M-TEER) is an established treatment option for patients with severe, symptomatic mitral regurgitation (MR). The real-world experience and outcomes with M-TEER in Canada has not been previously reported.

METHODS AND RESULTS: We conducted a multicenter, observational study of 1,191 consecutive patients from 11 Canadian centers undergoing M-TEER with Mitraclip. M-TEER databases from each participating center were centrally collected. Baseline, procedural and outcome variables were mapped and merged into a single Canada-wide database. The primary efficacy outcome was MR severity before versus up to 12 months after M-TEER. Secondary outcomes were hospitalizations for heart failure (HHF) and the composite of death or HHF 12 months before versus up to 12 months after M-TEER. Results were stratified according to MR etiology (functional or degenerative).

MR etiology was functional in 62% and degenerative in 38%. The mean age was 76 (± 10) years with DMR patients being older than FMR patients (80 vs 73 years). FMR patients were more likely to have prior coronary artery disease, myocardial infarction, revascularization and chronic kidney disease. Overall, the proportion of patients with MR severity ≥ 3+ was reduced from 97.3% prior to M-TEER to 11.0% after M-TEER (absolute difference 86.4%, 95% CI 84.2-88.6, P< 0.001). Hospitalization for heart failure was 50.7% in the 12 months prior to M-TEER versus 10.2% up to 12 months after M-TEER (absolute difference 40.4%, 95% CI 36.5-44.4, P< 0.001). NYHA functional class III-IV heart failure symptoms were present in 82.8% prior to M-TEER compared with 16.6% up to 12 months after M-TEER (absolute difference 66.2%, 95% CI 62.4-70.0, P< 0.0001). Compared with before M-TEER, HHF was consistently lower up to 1 year after M-TEER in patients with functional MR (61.5% vs 9.6%, absolute difference 33.2%, P< 0.001) and degenerative MR (43.7% vs 10.5%, absolute difference 33.2%, P< 0.001). Single leaflet device attachment and need for mitral valve surgery were infrequent (1.15% and 2.3%, respectively). Mortality was 2.1% in-hospital and 13.2% at 1 year.


Conclusion: In this first national registry of M-TEER in Canada, M-TEER with Mitraclip resulted in a sustained reduction in MR up to 12 months after the procedure and was associated with clinically important reductions in 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.