BACKGROUND: Right ventricular-to-pulmonary artery (RV-PA) coupling has recently been shown to be associated with outcome in valvular heart disease. However, longitudinal data on RV dysfunction and reverse cardiac remodeling in patients following transcatheter edge-to-edge mitral valve repair (M-TEER) are scarce. METHODS: Consecutive patients with primary as well as secondary mitral regurgitation (MR) were prospectively enrolled and had comprehensive echocardiographic and invasive hemodynamic assessment at baseline. Kaplan-Meier estimates and multivariable Cox-regression analyses were performed, using a composite endpoint of heart failure hospitalization and death. RESULTS: Between April 2018 and January 2021, 156 patients (median 78 y/o, 55% female, EuroSCORE II: 6.9%) underwent M-TEER. On presentation, 64% showed impaired RV-PA coupling defined as tricuspid annular plane systolic excursion to pulmonary artery systolic pressure (TAPSE/PASP) ratio <
0.36. Event-free survival rates at 2 years were significantly lower among patients with impaired coupling (57 vs. 82%, p <
0.001), both in patients with primary (64 vs. 91%, p = 0.009) and secondary MR (54 vs. 76%, p = 0.026). On multivariable Cox-regression analyses adjusted for baseline, imaging, hemodynamic, and procedural data, TAPSE/PASP ratio <
0.36 was independently associated with outcome (adj.HR 2.74, 95% CI 1.17-6.43, p = 0.021). At 1-year follow-up, RV-PA coupling improved (TAPSE: ∆ + 3 mm, PASP: ∆ - 10 mmHg, p for both <
0.001), alongside with a reduction in tricuspid regurgitation (TR) severity (grade ≥ II: 77-54%, p <
0.001). CONCLUSIONS: TAPSE/PASP ratio was associated with outcome in patients undergoing M-TEER for primary as well as secondary MR. RV-PA coupling, alongside with TR severity, improved after M-TEER and might thus provide prognostic information in addition to established markers of poor outcome.