Determinants of disproportionate functional mitral regurgitation

Abstract Funding Acknowledgements Type of funding sources: None. Background Recent studies have suggested that "disproportionate" functional mitral regurgitation (FMR) defined by greater MR than expected from the degree left ventricular (LV) dilatation may be a good candidate for transcatheter edge-to-edge repair (TEER). Determinants disproportionate FMR (d-FMR) is unknown. We hypothesized additional factors such as asymmetric tethering, extreme annular dilatation, and deep indentation, might worsen severity regardless LV volumes lead to d-FMR. Purpose To investigate impact on proportionality FMR. Methods reviewed consecutive patients who underwent TEER 3D transesophageal echocardiography (3DTEE) in our institute between 2018 2022. d-FMR proportionate (p-FMR) were effective regurgitant orifice area (EROA)/LV end-diastolic volume (LVEDV) >0.2 ≤0.2 mm2/mL, respectively. Results A total 110 (63 47 p-FMR, 75±12 years old, 46.3% female) included. Patients with had significantly larger EROA p-FMR (41 ± 12 vs 33 11 mm2, P<0.001) despite smaller LVEDV index (100 28 138 49 mL/m2, P<0.001), better ejection fraction (37 10% 27 8%, lower tenting height (7.6 ±2.9 9.4 2.7 mm, P=0.009). The 3DTEE analysis revealed more likely tethering (29% 21%), (>700 mm2/m2; 54% 30%), indentation (22% 4.3%) presence was independently associated (odds ratio 3.83, P=0.0081) after adjustment body surface index. Furthermore, EROA/LVEDV increased number increased. (Jonckheere-Terpstra test, P<0.001). successfully reduced factor (success rate 95% vs. 96%, P>0.99). Conclusions exacerbates size an important mechanism therapy reduce these factors.