EMCAPT study: the effect of MitraClip treatment on the mitral annulus and left atrial appendage evaluation by transoesophageal echocardiography

Abstract

Introduction: Data on the change in mitral valve annulus diameter (MAD), and left atrial appendage (LAA) structure and function after transcatheter edge-to-edge repair (TEER) of the mitral valve in patients with secondary mitral regurgitation (MR) are lacking.

Aim: To evaluate the change in these parameters just after the clip insertion and its relationship with prognosis in the long term.

Material and methods: A total of 50 patients (age: 71.5 ±11.3 years, 70% male) with moderate-to-severe or severe MR were included in the study. Transthoracic (TTE) and transoesophageal echocardiography (TEE) were performed before and after the procedure. Prognostic data were recorded with post-procedure telephone calls and follow-up visits.

Results: TEE performed during the procedure showed that LAA contraction and filling velocity significantly increased (p < 0.001 for all). Systolic pulmonary artery pressure (SPAP), MAD, and LAA landing zone dimension significantly decreased (p < 0.001 for all). There was only a significant correlation between the MAD before clip placement and the MAD change after clip placement (r = 0.6, p < 0.001). During a mean follow-up period of 10.5 ±8.9 months, no significant correlation was found between MAD change, LAA contraction and filling velocity change, and LAA landing zone dimension change and rehospitalization, stroke, mortality, and composite outcome.

Conclusions: The contraction and filling velocity of LAA, SPAP, MAD, and LAA landing zone dimension changed significantly immediately after the MitraClip procedure. Although these parameters are not related to composite outcome in our study, MAD, LAA diameter, and velocity need to be compared between successful and unsuccessful procedures to predict their clinical relevance.

Keywords: MitraClip; left atrial appendage; mitral annulus; mitral regurgitation.

Figure 1

Flow chart of the study subjects

Figure 2

The left atrial appendage landing zone (A), outflow and inflow flow velocities (B), and mitral annular diameter were measured during transesophageal echocardiography (C), 3D image after clip placement (D)

Figure 3

Number of clips per procedure (%)

Figure 4

The box plot graph compares pulmonary artery systolic pressure, mitral annular diameter, LAA landing zone, and LAA velocities before and after MitraClip LAAC – left atrial appendage contraction, LAAF – left atrial appendage filling, LAAL – left atrial appendage landing, MA – mitral annular, PASP – pulmonary artery systolic pressure.

Figure 5

Scatter graph of Spearman correlation analysis results showing the relationship between pre-procedure values of mitral annular diameter LAA landing zone and LAA flow velocities and post-procedure measurement changes LAA – left atrial appendage.

Figure 6

Frequency of cardiovascular events and mortality at a mean follow-up of 10.5 months