What is the clinical evidence from this study?

Study design: Cohort. Population: Mitral regurgitation undergoing M-TEER (n=3764). Intervention: Atrial fibrillation vs. No atrial fibrillation. Primary outcome: All-cause mortality within 2 years (adjusted HR 1.88, 95% CI 1.17-3.02, p=0.009).

What question did this study set out to answer?

This study investigates how atrial fibrillation impacts clinical outcomes after mitral transcatheter edge-to-edge repair based on the cause of mitral regurgitation.

May 8, 2026Open Access

Atrial Fibrillation and Clinical Outcomes Following Mitral Transcatheter Edge-to-Edge Repair According to Mitral Regurgitation Etiology

Q: What does this research mean for the field?

Atrial fibrillation is associated with a higher risk of 2-year all-cause mortality after mitral transcatheter edge-to-edge repair (M-TEER) in patients with degenerative mitral regurgitation, but not in those with ventricular or atrial functional mitral regurgitation. Novelty: ClaimNovelty.INCREMENTAL. Consensus alignment: ConsensusAlignment.NEUTRAL.

Key Result

Atrial fibrillation was associated with a higher risk of 2-year all-cause mortality after M-TEER in patients with degenerative mitral regurgitation (adjusted HR 1.88; 95% CI 1.17-3.02; P=0.009).

Key Points

This study investigates how atrial fibrillation impacts clinical outcomes after mitral transcatheter edge-to-edge repair based on the cause of mitral regurgitation.
Analyzed data from 3,764 patients undergoing mitral transcatheter edge-to-edge repair, categorized by mitral regurgitation types: DMR, VFMR, AFMR.
Stratified patients based on the presence of atrial fibrillation and examined outcomes over a median follow-up of 427 days.
Primary endpoint was all-cause mortality after M-TEER.
17.5% of patients died during follow-up; AF was present in 57.4% of DMR, 59.7% of VFMR, and 83.8% of AFMR.
AF was associated with increased all-cause mortality in DMR (adjusted HR: 1.88; 95% CI: 1.17-3.02; P = 0.009), but not significantly in VFMR or AFMR.
In VFMR, lower left atrial volume index revealed a stronger association between AF and mortality, whereas higher volume index weakened this relationship.

Study Design

Type

Cohort (n=3,764)

Structured PICO

Does atrial fibrillation increase the risk of all-cause mortality in patients undergoing mitral transcatheter edge-to-edge repair across different mitral regurgitation etiologies?

Population

3,764 patients undergoing mitral transcatheter edge-to-edge repair (M-TEER), classified into degenerative mitral regurgitation (DMR, n=1,126), ventricular functional mitral regurgitation (VFMR, n=2,211), and atrial functional mitral regurgitation (AFMR, n=427).

Intervention

Presence of atrial fibrillation (AF)

Comparator

Absence of atrial fibrillation (AF)

Outcome

All-cause mortality within 2 yearshard clinical

Atrial fibrillation is associated with increased all-cause mortality after M-TEER in patients with degenerative mitral regurgitation, but not in those with ventricular or atrial functional mitral regurgitation.

Main Result

Effect estimate: adjusted HR 1.88 (95% CI 1.17-3.02)

p-value: p=0.009

Abstract

BACKGROUND: The association between atrial fibrillation (AF) and prognosis after mitral transcatheter edge-to-edge repair (M-TEER) remains unclear. OBJECTIVES: The authors examined the association between AF and clinical outcomes after M-TEER according to the etiology of mitral regurgitation (MR). METHODS: A total of 3,764 patients were classified into degenerative mitral regurgitation (DMR), ventricular functional mitral regurgitation (VFMR), and atrial functional mitral regurgitation (AFMR). We further stratified the patients by the presence of AF. The primary outcome was all-cause mortality within 2 years. RESULTS: The prevalence of AF was 57.4% (n = 646 of 1,126) in DMR, 59.7% (n = 1,319 of 2,211) in VFMR, and 83.8% (n = 358 of 427) in AFMR. During 2-year follow-up (the median follow-up: 427 IQR: 301-821 days), 660 of 3,764 patients (17.5%) died. The association between AF and all-cause mortality had a significant interaction with MR etiology (P for interaction <0.001). AF was associated with a higher risk of all-cause mortality in DMR (adjusted HR: 1.88; 95% CI: 1.17-3.02; P = 0.009), whereas this association was not significant in VFMR and AFMR. Among patients with VFMR, left atrial (LA) volume index modified the association between AF and all-cause mortality. AF was related to a higher risk of all-cause mortality in VFMR patients with lower LA volume index, whereas this association was attenuated in those with higher LA volume index. CONCLUSIONS: AF was associated with all-cause mortality after M-TEER in patients with DMR, but not in those with VFMR or AFMR. The prognostic effect of AF in patients undergoing M-TEER may be modulated by MR etiology and underlying LA remodeling.