Background: Secondary mitral regurgitation (SMR) is associated with adverse outcomes and the optimal treatment modality remains challenging due to extensive variety in the pathology of SMR. Trancatheter direct annuloplasty using the Cardioband system emerged as a promising treatment in selected patients. However, success predictors of this intervention and their association with prognosis remain unclear. 

Methods: We retrospectively analyzed patients who underwent catheter-based direct annuloplasty with the Cardioband system for SMR at five tertiary centers in Germany and Switzerland between 2013 and 2020. Patients with procedural success (defined as postprocedural MR grade <=2+) were compared to those with MR>2+ with respect to baseline echocardiographic data and outcome.

Results: We included 130 patients (median age 75.5 [71-79], 37% female). Most patients were severely symptomatic (NYHA class III/IV 86.9%), had a median EF of 39 (29-52) with an ischemic etiology in 39%. Procedural success was achieved in 68%. Procedural time was 178.5 (147.5-214.5) minutes. Patients with and without procedural success differed significantly in measures of MR severity (grade, vena contracta, effective regurgitation orifice area and regurgitation volume), annular dilatation (leaflet length and LA sphericity index at end-systole) and leaflet tethering (tenting area, regurgitation jet direction). In multivariable analysis including significant measures of annular dilatation and leaflet tethering, predictors of procedural treatment success were tenting area (OR 0.68, 95%CI 0.47-0.98 per mm2, p=0.04) and central regurgitation jet direction (OR 2.6; 95%CI 0.99-6.84, p=0.05). After adjustment for SMR severity, associations were virtually unchanged.

NYHA class III/IV at last follow up was significantly different between groups, with 34.1% vs. 55.2% of patients with vs. without procedural success, respectively (p=0.04). The combined endpoint of mortality or reintervention at 1 year was significantly lower in patients with procedural success (27% vs. 63%, p=0.002), whereas the association of procedural success with 1-year mortality was of borderline significance (13% vs. 32%, p=0.05).

Conclusion: Two third of all patients undergoing transcatheter direct annuloplasty for SMR had procedural success. Careful patient selection after assessment of mitral valve deformation is imperative for procedural success, which translates to less symptom burden and significantly less combined endpoint of mortality or reintervention.