Registries on transcatheter edge-to-edge repair in heart failure: Current evidence and future perspectives

Aims: Secondary mitral regurgitation (SMR) and tricuspid regurgitation (TR) are the most common valvular heart diseases in patients with heart failure (HF). Transcatheter edge-to-edge repair (TEER) devices designed for treating MR and TR have been successfully tested in randomized controlled trials, but methodological issues have often challenged their interpretation. This manuscript aimed to provide an overview of TEER registries on SMR and TR in HF, highlighting their key features, describing clinical characteristics and outcomes of patients receiving these devices, and exploring the available data limitations. Methods and results: PubMed, Web of Science, and EMBASE were searched for registries reporting on TEER in SMR or TR. Registries were excluded if single-centre and with <100 patients. Twenty-six registries (46% prospective, 12% ongoing), including a total cohort of 18 925 patients, were retrieved for TEER in SMR, and six registries (50% retrospective, 33% ongoing) reported on the use of TEER for TR in a total cohort of 1412 patients. Limited geographical representativity outside North America and Europe, high number of missing values, and inconsistency in data reporting were the main existing evidence limitations. Conclusion: Registries on TEER represent a key data source in a setting where it is difficult to conduct randomized controlled trials. However, limitations in design, patient characterization, and outcomes reporting restrain their use. A novel conceptual framework for future prospective TEER registries, as proposed in this document, might inform current practice, address relevant clinical questions and future trial design.