The transkatheter edge-to-edge mitral valve repair (M-TEER) is an established prognosis-improving treatment for patients with severe mitral valve regurgitation. However, current data show that concomitant dysfunction of the right ventricle can significantly worsen the prognosis after interventional M-TEER. 
Therefore, the main objective of this study is a comprehensive analysis of right ventricular function before and after interventional M-TEER using invasive pressure-volume measurements and non-invasive methods such as 3D cardiac ultrasound and blood biomarker determinations. The aim is to identify important predictors of poor prognosis after interventional M-TEER, which could significantly improve patient selection.