Echocardiography and computed tomography predictors of successful transcatheter direct annuloplasty for mitral regurgitation
Authors: Iliadis C , Weber M , Horn P , Harr C , Gavazzoni M , Nickenig G , Westenfeld R , Alessandrini H , Taramasso M , Baldus S , Pfister R 
Published: October 2022

Abstract

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. Percutaneous 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.

Purpose
To investigate the role of echocardiographic and computed tomography (CT) data in patients with SMR undergoing percutaneous direct annuloplasty.

Methods
We retrospectively analyzed patients who underwent catheter-based direct annuloplasty with the Cardioband system for SMR at five tertiary centres in Germany and Switzerland between 2013 and 2020. Patients with procedural success (defined as postprocedural MR grade ≤2+) were compared to those with MR &gt;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 ischaemic 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 (defined as postprocedural SMR severity (grade, vena contracta (VC), effective regurgitation orifice area and regurgitation volume), annular dilatation (leaflet length, LA sphericity index at end-systole and CT-derived intercommissural distance) and leaflet tethering (tenting area, regurgitation jet direction). In multivariable analysis of echocardiographic parameters including significant measures of annular dilatation and leaflet tethering, predictors of procedural treatment success were tenting area (OR 0.54; 95% CI 0.33–0.98 per mm2, p=0.016) and central regurgitation jet direction (OR 2.96; 95% CI 1.06–8.25, p=0.038). After adding CT data in the multivariable model, intercommissural distance proved to be the most significant predictor (OR 0.96; 0.92–0.99, p=0.009), whereas VC was the only echo predictor (OR 0.84; 0.73–0.98, p=0.03).
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 thirds of patients undergoing transcatheter direct annuloplasty for SMR had procedural success. Careful patient selection by assessment of mitral valve anatomy is helpful to predict procedural success, which translates into less symptom burden and better clinical outcome.

Funding Acknowledgement
Type of funding sources: None.