Abstract Body (Do not enter title and authors here): Introduction: Left ventricular (LV) reverse remodeling after mitral transcatheter edge-to-edge repair (MTEER) is a well-observed phenomenon. However, there is limited and variable evidence regarding whether men and women experience comparable patterns of reverse remodeling.

Aim: To assess changes in LV geometry and elucidate sex differences in remodeling following MTEER.

Methods: This single-center retrospective study included consecutive adult patients who underwent MTEER with MitraClip from 2021-2022 and received comprehensive echocardiography at both baseline (prior to procedure) and follow-up (both 30 days and 1 year post-procedure). Baseline echocardiographic, demographic, and clinical data were compared between sexes. Changes in 30-day and 1-year LV diameter, volume, and mass were compared within each sex to baseline data via paired t-tests.

Results: Out of 95 patients who underwent MTEER with complete echo data, 46 (47.4%) were men and 49 (50.5%) were women. Women were older than men at the time of procedure (79.3 vs. 83.3 years, p=0.017). There were no other significant differences in relevant co-morbidities or LV function and geometry on baseline echo. Both sexes saw a significant decrease in LVEDVi at 1 year (88.8 to 84.1 mL/m2, p=0.031 in men; 70.2 to 58.2 mL/m2, p=0.008 in women). Women had significantly decreased LVESVi (34.0 to 28.6 mL/m2, p=0.033) and LVMi (113.2 to 96.8 g/m2, p=0.041) at 1 year, while men did not. Men had decreases in LVEDD (5.62 to 5.35 cm, p=0.033) and LVESD (4.35 to 3.82 cm, p=0.006) at 30 days; the reduction in LVEDD remained significant at 1 year (5.62 to 5.36 cm, p=0.004).

Conclusions: Both men and women demonstrated reverse remodeling after MTEER; these changes varied between sexes by specific echo parameters and time course. Women had reduced LVMi and LVESVi one year after MitraClip, whereas men did not. Men experienced earlier reductions in LV diameter; however only one marker of LV diameter (LVEDD) saw sustained reduction at one year. Larger studies are necessary to confirm our findings.