# Comparison of Meta-Analytical Estimates Between Surgical Repair and Transcatheter Edge-to-Edge Repair for Atrial Functional Mitral Regurgitation

## TL;DR

This study compares surgical and transcatheter treatments for atrial functional mitral regurgitation, finding that surgery may offer better long-term outcomes.

## Contribution

The study provides a meta-analysis comparing surgical and transcatheter repair for atrial functional mitral regurgitation, highlighting long-term benefits of surgery.

## Key findings

- Surgery was associated with decreased late severe MR and mortality compared to transcatheter repair.
- Short-term outcomes were comparable between the two treatments.
- High heterogeneity in long-term outcomes suggests the need for further validation.

## Abstract

Atrial functional mitral regurgitation (MR) lacks well-defined treatment guidelines. Medical therapy alone is insufficient, and either TEER (transcatheter edge-to-edge) or surgery is recommended. Short- and long-term comparative outcomes remain unclear. We aim to address this gap using available data.

We performed a meta-analysis of studies examining the outcomes of surgery and/or transcatheter edge-to-edge. MEDLINE, EMBASE, and the Cochrane Library were assessed. The incidence rate of late severe MR was the primary outcome. A random model was performed. Leave-one-out, subgroup, and meta-regression analyses were conducted.

Thirty-two studies (1923 patients); 20 in surgery (1166) vs 12 in TEER (757), were selected. TEER patients were, on average, 10 years older, with twice the rate of New York Heart Association Classification (NYHA) III/IV symptoms and more than double the Society of Thoracic Surgeons Risk (STS) score. At a weighted mean follow-up of 3.2 years, compared to isolated transcatheter, surgery was associated with decreased incidence of late severe MR (2.53 vs 6.66 events per 100 person-years, P-interaction = .03), late all-cause mortality (3.00 vs 8.84, P-interaction = .024), late heart failure hospitalization (4.44 vs 17.03, P-interaction < .01), and late NYHA III/IV (2.98 vs 22.47, P-interaction < .01). However, significantly better long-term outcomes associated with surgery showed high heterogeneity. There were no differences in early all-cause mortality, early cardiac-specific mortality, late cardiac-specific mortality, postprocedural morbidities, or atrial diameter. On meta-regression, preprocedural heart failure (β = 0.0224, P < .01) and coronary artery disease (β = 0.0294, P < .00001) were linked to increased late severe MR. Older age, hypertension, mitral valve replacement, and associated aortic valve surgery were linked to increased late all-cause mortality.

Surgery and isolated transcatheter edge-to-edge repair showed comparable short-term outcomes, with surgery appearing more effective long-term; however, due to study limitations and heterogeneity, these findings are hypothesis-generating and require validation through prospective studies.

PROSPERO website: CRD42024504022.

While we hypothesize that the superior outcomes of surgery compared to isolated TEER is related to the direct repair of the dilated mitral annulus, concomitant tricuspid valve repair and atrial fibrillation ablation, the causal relationship remains unclear.