Transthoracic and transoesophageal echocardiography for tricuspid transcatheter edge-to-edge repair: a step-by-step protocol

: Tricuspid regurgitation (TR) carries an unfavourable prognosis and often leads to progressive right ventricular (RV) failure. Secondary TR accounts for over 90% of cases and is caused by RV and/or tricuspid annulus dilation, in the setting of left heart disease or pulmonary hypertension. Surgical treatment for isolated TR entails a high operative risk and is seldom performed. Recently, transcatheter edge-to-edge repair (TEER) has emerged as a low-risk alternative treatment in selected patients. Although the experience gained from mitral TEER has paved the way for the technique's adaptation to the tricuspid valve (TV), its anatomical complexity necessitates precise imaging. To this end, a comprehensive protocol integrating 2D and 3D imaging from both transthoracic echocardiography (TTE) and transoesophageal echocardiography (TOE) plays a crucial role. TTE allows for an initial morphological assessment of the TV, quantification of TR severity, evaluation of biventricular function, and non-invasive haemodynamic evaluation of pulmonary circulation. TOE, conversely, provides a detailed evaluation of TV morphology, enabling precise assessment of TR mechanism and severity, and represents the primary method for determining eligibility for TEER. Once a patient is considered eligible for TEER, TOE, alongside fluoroscopy, will guide the procedure in the catheterization lab. High-quality TOE imaging is crucial for patient selection and to achieve procedural success. The present review examines the roles of TTE and TOE in managing patients with severe TR eligible for TEER, proposing the step-by-step protocol successfully adopted in our centre.