This prospective observational study aims to investigate the impact of transcatheter aortic valve implantation (TAVI) and transcatheter mitral valve edge-to-edge repair (M-TEER) on sleep-disordered breathing (SDB) in patients with significant valvular heart disease. Patients undergoing TAVI or M-TEER will be evaluated with full polysomnography prior to the intervention and at 6 months follow-up. Changes in sleep parameters, including apnea-hypopnea index (AHI), central and obstructive apnea indices, oxygen desaturation, and sleep architecture, will be assessed. In addition, the study will explore the association between changes in SDB and echocardiographic as well as arrhythmic parameters. The findings are expected to improve the understanding of the interaction between valvular heart disease and SDB and to identify potential benefits of transcatheter interventions on sleep-related outcomes.