Diametrically opposed results of the COAPT- and the MITRA-FR trial have demonstrated the need for additional evidence in the field of transcatheter mitral edge-to-edge repair. Reverse left ventricular remodeling after treatment of severe secondary mitral regurgitation can indicate treatment response and is associated with positive outcomes.~However, so far it is reverse remodeling, respectively treatment response is difficult to predict, which complicates patient selection for mitral edge-to-edge repair. Previous studies have shown, that focal (late gadolinium enhancement (LGE)) but not diffuse myocardial fibrosis (T1 mapping and extracellular volume fraction (ECV)) burden quantification using CMR predicts reverse left ventricular remodeling following cardiac resynchronization therapy in patients with heart failure with reduced ejection fraction (HFrEF). On the other hand, myocardial T1 mapping was predictive for beneficial left ventricular remodeling after long-term heart failure therapy. Furthermore, in patients with HFrEF, LGE is associated with clinical outcome and an incremental predictive value to left ventricular dimensions and function. However, as only 1/3 of HFrEF patients show LGE, subtle fibrosis might be missed. Recently the investigators have shown that different novel fibrosis detection techniques (naive T1 mapping, mean ECV and λGd being the delta of pre- and post T1 mapping and ECV calculation) all demonstrated strong association with outcome in patients with heart failure.~The investigators' hypothesis is that these markers (CMR tissue characterization and myocardial function analysis acquired by a CMR feature tracking) might also be helpful in predicting reverse remodeling after transcatheter mitral edge-to-edge repair. This project might help to understand the pathophysiology of the disease in patients with secondary mitral regurgitation, improve risk stratification in this clinical setting, and optimize selection of patients who benefit from transcatheter mitral edge-to-edge repair.
The investigators' hypothesis is that CMR tissue characterization and myocardial function analysis acquired by CMR feature tracking technique predict reverse remodeling in patients with severe secondary mitral regurgitation (MR) undergoing transcatheter mitral edge-to-edge repair.