Quantitative 3D-TEE Analysis of Mitral Valve Geometry for TEER Strategy in Atrial Functional Mitral Regurgitation

BACKGROUND: Atrial functional mitral regurgitation (AFMR) is a distinct subtype of secondary MR in patients with atrial fibrillation (AF). Although mitral transcatheter edge-to-edge repair (M-TEER) is increasingly performed under 3D transesophageal echocardiography (TEE) guidance, detailed characterization of 3D mitral valve geometry relevant to procedural strategy remains limited. OBJECTIVES: To investigate the impact of mitral valve geometrical parameters on preprocedural planning and outcomes of M-TEER in AFMR. METHODS: Patients with AFMR undergoing M-TEER with analyzable intraprocedural 3D-TEE data were retrospectively enrolled. We evaluated whether the total leaflet area to mitral annulus area ratio (TLA/MAA) was associated with procedural strategy (1 vs. 2 devices) and procedural failure, defined as residual MR ≥2+ and/or post-procedural transmitral mean pressure gradient (MPG) ≥5 mmHg. RESULTS: Among 130 patients (mean age 78.1 years; 60.8% male; 93.4% AF), residual MR ≥2+ occurred in 31 patients and post-M-TEER MPG ≥5 mmHg in 35 patients. Thirty patients received 2 devices. Lower TLA/MAA was associated with residual MR ≥2+, use of 2 devices, and post-procedural MPG ≥5 mmHg. Under the composite definition of procedural success (MR <2+ and MPG <5 mmHg), TLA/MAA outperformed mitral annulus area in predicting success with one device (AUC 0.79 vs. 0.53; p<0.001). CONCLUSIONS: In AFMR, 3D TEE-derived TLA/MAA can provide geometrical information to guide preprocedural M-TEER strategy to balance MR reduction and transmitral gradient.