Left Ventricular Function and Atrial Remodeling Shape Outcomes After Mitral-Transcatheter Edge-to-Edge Repair

Secondary mitral regurgitation (SMR) contributes substantially to morbidity and mortality in heart failure. Mitral transcatheter edge-to-edge repair (M-TEER) improves outcomes in patients with reduced left ventricular ejection fraction (LVEF), but evidence in patients with preserved LVEF-often reflecting atrial functional mitral regurgitation-remains limited.

We retrospectively analyzed 93 consecutive patients with symptomatic SMR treated with M-TEER between 2018 and 2022. Patients were stratified according to LVEF (<50% vs ≥50%) and left atrial volume index (LAVI <60 vs ≥60 mL/m2). The primary endpoint was comprehensive clinical improvement at 36 months, defined as survival without heart-failure hospitalization, New York Heart Association (NYHA) class I-II, and Kansas City Cardiomyopathy Questionnaire (KCCQ) score >60. Kaplan-Meier and Cox proportional hazards analyses were performed.

Among 87 patients with complete follow-up, 48 (55%) achieved the composite endpoint. Clinical improvement rates were similar in patients with reduced and preserved LVEF (51.8% vs 62.5%, p=0.32). All-cause mortality at 36 months was lower in preserved compared with reduced LVEF (9.4% vs 29.6%; log-rank p=0.03). Enlarged left atrial volume (LAVI ≥60 mL/m2) was associated with increased mortality (29.4% vs 11.8%; log-rank p=0.04). In Cox regression analyses adjusted for age and sex, LAVI remained associated with mortality risk.

M-TEER provides sustained clinical benefit across the LVEF spectrum, including patients with preserved LVEF. Left atrial enlargement identifies patients with worse prognosis and may represent a marker of advanced atrial disease supporting earlier intervention.