Left atrial remodeling and diastolic unloading after transcatheter tricuspid repair

Background Severe tricuspid regurgitation (TR) elevates left-heart filling pressures via septal shift. Whether transcatheter tricuspid edge-to-edge repair (T-TEER) reverses these changes remains uncertain. Purpose To quantify left-atrial (LA) volume and diastolic-pressure surrogates after T-TEER. Methods In 108 consecutive patients we measured LA volume index (LAVI), E/e′ ratio, peak atrial longitudinal strain (PALS) and LA stiffness index (LASI = E/e′⁄PALS) at baseline, predischarge (PreDC), 6 months and 12 months. Time effects were assessed with patient-level linear mixed-effects models; patients were stratified by baseline left-ventricular ejection fraction (LVEF) ≥ or < 50 %. Results LAVI fell by PreDC (Δ –6.1 mL/m²; p<0.001) and remained stable thereafter. E/e′ and LASI rose acutely (+3.6 and +0.75; both p<0.01) then regressed to near-baseline by 6 months, with no further change to 12 months. PALS was unchanged early and declined slightly at 12 months (Δ –1.0 %; p = 0.002). Stroke volume showed no significant change. Time × LVEF interaction was non-significant for all metrics (all p > 0.5). Conclusions T-TEER produces rapid LA decompression with transient diastolic-load surges that resolve by 6 months. LASI and E/e′ capture these shifts and may serve as practical non-invasive markers; PALS did not recover. Remodeling was independent of baseline systolic function.