Prediction of procedural success of transcatheter mitral valve repair with normal and extended clip arms

Abstract

TMVR using different clip sizes is a treatment option for selected patients with mitral regurgitation (MR). This study sought to identify predictors of successful transcatheter mitral valve repair (TMVR) by 3-dimensional (3D) echocardiography and to compare different effects of the larger XTR and the smaller NT/NTR devices. 3D transesophageal echocardiography was performed on 54 patients with secondary MR undergoing TMVR with one clip (55.6% NT/NTR, 44.4% XTR). All NT/NTR and 96% of XTR patients had MR reduction ≤ 2+. Despite more severe baseline MR (3D vena contracta area (VCA): 0.67 ± 0.34 cm2 vs. 0.43 ± 0.19 cm2, p = 0.004) and greater mitral valve area (MVA) (6.8 ± 2.1 cm2 vs. 5.1 ± 1.6 cm2, p = 0.001) in the XTR group, MR severity after TMVR was not different between XTR and NT/NTR patients (3D VCA: 0.19 ± 0.14 vs. 0.17 ± 0.10, p = 0.51). Baseline 3D VCA > 0.45 cm2 in NT/NTR (AUC = 0.802, 95% CI 0.602 to 1.000) and 3D VCA > 0.54 cm2 in XTR devices (AUC = 0.868, 95% CI 0.719 to 1.000) were associated with ineffective MR reduction defined as residual VCA ≤ 0.2 cm2. Baseline MVA ≤ 4.2 cm2 in NT/NTR (AUC = 0.920, 95% CI 0.809 to 1.000) and MVA ≤ 6.0 cm2 in XTR devices (AUC = 0.865, 95% CI 0.664 to 1.000) were associated with postprocedural transmitral pressure gradient (TMPG) ≥ 5 mmHg. TMVR using the XTR device resulted in an equally effective reduction of MR despite of a greater baseline MR. Distinct cut-off values of baseline 3D VCA and MVA for prediction of successful MR reduction and postprocedural increase of TMPG were identified for the different devices.