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

Background 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. Methods 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. Results 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. Conclusion 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.