Findings from transoesophageal echocardiographic follow-up after mitral transcatheter edge-to-edge repair.

Background: Transoesophageal echocardiography (TOE) provides accurate evaluation of mitral valve (MV) function following mitral transcatheter edge-to-edge repair (M-TEER) and may better detect complications in case of suboptimal result.

Aims: We aimed to evaluate midterm anatomical changes and structural complications after M-TEER using TOE and investigate their association with clinical outcomes at 2 years.

Methods: A follow-up TOE at 6 months was systematically recommended to all patients included in our institutional prospective M-TEER registry until December 2021. We assessed changes in the incidence of mitral regurgitation (MR), MV stenosis (≥5 mmHg), and partial or complete single leaflet device attachment (SLDA) between the index procedure and follow-up and evaluated MV area and annular dimensions in a subset of patients with available three-dimensional (3D) datasets. The clinical endpoint was a composite of mortality and heart failure (HF) rehospitalisation at 2 years.

Results: Among the 373 patients included in the registry between February 2012 and December 2021, 128 patients (34%) underwent elective TOE at 6 months. Using TOE, severe MR was observed in 13.3% (n=17) of the patients. The number of patients with an elevated MV gradient increased from 17 (13.3%) after the procedure to 23 (18%) at 6 months, and a new partial or complete SLDA was detected in 7.8% (n=10). Based on 3D TOE measurements, significant increases in MV area, annular area, annular perimeter, and intercommissural (but not anteroposterior) diameter were observed compared to intraprocedural images. A mean MV gradient ≥5 mmHg (hazard ratio [HR] 2.30, 95% confidence interval [CI]: 1.10-4.81; p=0.023) and the presence of severe MR at 6 months (HR 3.26, 95% CI: 1.18-8.99; p=0.023) were associated with the primary endpoint, which was met in 34 (26.6%) patients at 2 years.

Conclusions: TOE follow-up allowed the detection of complications that would not be diagnosed using transthoracic echocardiography only and should therefore be used liberally in the patients presenting with a suboptimal result. A mean MV gradient ≥5 mmHg and severe MR, diagnosed at the 6-month TOE follow-up, were associated with adverse clinical outcomes.