Outcome of transcatheter mitral valve repair in heart failure patients with reduced ejection fraction and severe left ventricular dilatation

Abstract

Abstract Introduction The COAPT trial demonstrated the benefit of transcatheter edge­to­edge mitral valve repair (TEER) for heart failure patients who had reduced ejection fraction (HFrEF) with symptomatic secondary mitral regurgitation (MR). However, patients with severe left ventricular (LV) dilatation were not included in the COAPT trial. Furthermore, disproportionate LV dilatation was suggested as a possible explanation for the lack of benefit in the MITRA­FR trial. Purpose The purpose of this study was to assess the safety and efficacy of TEER in HFrEF patients with severe LV dilatation. Methods We studied 75 HFrEF patients who underwent mitral valve repair between 2018-2021. Reduced LV ejection fraction (LVEF) was defined as LVEF of 40% or less. These patients were categorized with and without severe LV dilatation based on left ventricular end-diastolic volume index (LVEDVI) using a median cut­off value of >139ml/m2 in men and >128cm/m2 in women. Results There were 37 patients with severe LV dilatation (D) and 38 without (ND). Median LVEDVI was 172 [149-190] ml/m2 in the D group vs 120 [105-127] ml/m2 in the ND group. Compared to the ND patients, patients with severe LV dilatation were more treated with SGLT2-inhibitor (rate 24% vs 3%), had lower LVEF (30 [25-31] % vs 32 [30-36] %), and higher BNP (1160 [683-2586] vs 619 [396-1253] pg/ml). There was no significant difference in MR grade (4 [3-4] vs 4 [3-4]), EROA (0.32 [0.22-0.66] vs 0.34 [0.24-0.48] cm2), NYHA class (3 [2-4] vs 3 [2-3]) and mean systolic pulmonary pressure (31 [20-43] vs 34 [25-41] mmHg). Peri­procedural adverse events were rare in both groups. 1 patient had pseudoaneurysm in the ND group, and 1 patient had cardiogenic shock and 1 patient had stroke after the procedure in the D group. At discharge, there was marked improvement in MR grade (1 [1-2] vs 1 [1-2] for both). D group had a tendency of higher reduction in LVEDVI (-12 [-24--1] vs -5[-13-4] ml/m2) than ND group. BNP level of the D group had a significantly higher degree of decline before discharge (-458 [-141--1566] to -102 [+51--306] pg/ml) than that of ND group. No differences were noted in mortality between two groups (Figure). Conclusion TEER in HFrEF patients with severe LV dilatation seems to provide similar outcomes compared to patients with less severe dilatation. Further studies are needed to clarify the indication and establish the effectiveness of TEER in these patients.