# Midterm Outcomes of Transcatheter Edge-to-Edge Repair for Primary Mitral Regurgitation According to Anatomical Characteristics

## TL;DR

This study shows that anatomical complexity of the mitral valve affects outcomes in patients undergoing a minimally invasive heart procedure for severe mitral regurgitation.

## Contribution

The first long-term study (over 10 years) analyzing how mitral valve anatomy affects outcomes of transcatheter edge-to-edge repair for primary mitral regurgitation.

## Key findings

- Patients with A2-P2 prolapse/flail had better echocardiographic and symptomatic outcomes than non-A2-P2 groups.
- Complex mitral valve anatomy was associated with higher 1-year mortality compared to noncomplex anatomy.
- Technical success rate of M-TEER exceeded 90%, and the procedure effectively reduced mitral regurgitation and improved symptoms.

## Abstract

Mitral transcatheter edge-to-edge repair (M-TEER) is an established option for high-risk primary mitral regurgitation (PMR) patients, but data on the impact of anatomical complexity on prognosis are scarce and conflicting.

The aims of this study were to characterize patients with severe PMR undergoing M-TEER, assess mid-term prognosis after M-TEER, and identify prognostic factors based on PMR mechanism.

Data from symptomatic PMR patients with severe PMR treated with M-TEER between July 2013 and October 2023 at two Swiss centers were collected retrospectively until 2017 and prospectively thereafter. Patients were categorized by lesion type: A2-P2 prolapse/flail vs. non-A2-P2 prolapse/flail. A subset was classified by mitral valve (MV) anatomical complexity (defined by the presence of ≥1 of the following: ≥moderate calcifications, Barlow’s disease, multiple prolapses, or commissural prolapses). Cox regression identified predictors of 1-year all-cause mortality.

Among 315 patients (mean age 82.2 ± 6.3 years, 46.3% female, European System for Cardiac Operative Risk Evaluation II 5.1% ± 4.1%) followed for a median (interquartile range [IQR]) of 13 months (5-33), technical success was 93.0%. Compared with the non-A2-P2 prolapse/flail group (n = 186), the A2-P2 prolapse/flail group (n = 129) had better echocardiographic outcomes at discharge (residual mitral regurgitation [MR] ≤ 1+: 70.5 vs. 60.4%; p = 0.031) and superior symptomatic improvement at 1 year (New York Heart Association class ≤ II: 91.4 vs. 74.5%; p = 0.017) but similar 1-year all-cause mortality (15.1 vs. 18.8%; p = 0.492). Among patients classified by MV anatomical complexity (n = 143), patients with complex MV anatomy (n = 68) had a higher mortality at a median (IQR) follow-up of 22 months (9-36) compared to those with noncomplex MV anatomy (n = 75) (51.5 vs. 34.7%; p = 0.042). Multivariate analysis identified complex MV anatomy and severe renal failure as predictors of 1-year all-cause mortality.

MV anatomical characteristics have a significant influence on symptomatic improvement and all-cause mortality at 1 year and should be carefully considered during the selection of PMR patients for M-TEER.

Graphical Abstract: Midterm Outcomes of Trantscatheter Edge-to-Edge Repair for Primary Mitral Regurgitation According to Anatomical Characteristics. MV, mitral valve; MR, mitral regurgitation; M-TEER, mitral transcatheter edge-to-edge repair; PMR, primary mitral regurgitation.

•Mitral transcatheter edge-to-edge repair (M-TEER) is an established treatment option in patients with primary mitral regurgitation (PMR) at high or prohibitive surgical risk. Data regarding the impact of anatomical complexity on prognosis are scarce and conflicting.•Our study on M-TEER for PMR according to anatomy is the first to include patients treated over a period of more than 10 years. We demonstrate that, regardless of the underlying mitral regurgitation (MR) lesion, M-TEER is a safe procedure that effectively reduces PMR and alleviates symptoms with a high technical success rate (>90%).•In addition to clinical comorbidities, our data show that mitral valve (MV) anatomical characteristics are associated with outcomes and should thus be considered in the selection of PMR patients undergoing M-TEER.•Future larger-scale and mechanistic studies are needed to address long-term outcomes of M-TEER according to anatomy, focus on PMR patients with complex MV anatomy, and confirm the durability and safety of this treatment approach.

Mitral transcatheter edge-to-edge repair (M-TEER) is an established treatment option in patients with primary mitral regurgitation (PMR) at high or prohibitive surgical risk. Data regarding the impact of anatomical complexity on prognosis are scarce and conflicting.

Our study on M-TEER for PMR according to anatomy is the first to include patients treated over a period of more than 10 years. We demonstrate that, regardless of the underlying mitral regurgitation (MR) lesion, M-TEER is a safe procedure that effectively reduces PMR and alleviates symptoms with a high technical success rate (>90%).

In addition to clinical comorbidities, our data show that mitral valve (MV) anatomical characteristics are associated with outcomes and should thus be considered in the selection of PMR patients undergoing M-TEER.

Future larger-scale and mechanistic studies are needed to address long-term outcomes of M-TEER according to anatomy, focus on PMR patients with complex MV anatomy, and confirm the durability and safety of this treatment approach.