Standardized 3D Transoesophageal Echocardiography Manoeuvre for Enhanced Tenting Height Evaluation During Transcatheter Mitral Valve Edge-to-Edge Repair

Background: Transcatheter treatments for structural heart disease, including edge-to-edge mitral valve repair (mTEER), heavily rely on transoesophageal echocardiography (TOE) for pre-procedural assessment and guidance. Trans-septal puncture (TSP) is one of the first key steps of such procedures, with two-dimensional (2D) TOE often providing suboptimal imaging. Three-dimensional (3D) echocardiography could overcome the limitations of 2D TOE and improve the assessment of tenting height. Methods: This single-centre, retrospective study included 64 patients who underwent mTEER between October 2023 and April 2024. Tenting height during TSP was assessed by 2D TOE in mid-oesophageal (ME) four-chamber view and by 3D TOE after the acquisition of a 3D volume, including the interatrial septum, aortic valve, and mitral valve, and subsequent multiplanar reconstruction (MPR). A total of 100 TSP attempts with 2D and 3D TOE were evaluated. Results: Procedural success was obtained in 92.2% of cases. There was a statistically significant difference between 2D and 3D measurements (2D: 4.36 +/- 0.61 cm, MPR: 4.59 +/- 0.63 mm(2), p < 0.001), despite good correlation (r = 0.880, p < 0.001). The difference between 2D and 3D tenting height measurements differed significantly between patients with optimal and suboptimal 2D image windows (p < 0.001). There was no significant difference in septal puncture success between optimal 2D and 3D data (p = 0.942). Conclusions: Adopting 3D TOE with multiplanar reconstruction for assessing tenting height in mTEER procedures offers significant advantages over traditional 2D TOE. Enhanced visualization, accuracy, and potential for standardization improve procedural outcomes and patient safety, making 3D TOE integration into routine practice highly beneficial and recommended.