Adaptation of right ventricular function following tricuspid transcatheter edge-to-edge repair

Background: The impact of tricuspid transcatheter edge-to-edge repair (T-TEER) on right ventricular (RV) remodelling remains unclear. Objectives: This study focused on characterizing changes in RV ejection fraction (RVEF) following T-TEER and their prognostic implications. Methods: Patients with significant tricuspid regurgitation (TR) who underwent T-TEER and cardiac magnetic resonance (CMR) imaging were included. Follow-up CMR was performed within 1 to 3 months after the procedure. Patients were classified by postprocedural RVEF change: decreased (≤−5%), stable (−4% to 4%) or increased (≥5%). The primary outcome was a composite of all-cause mortality or heart failure hospitalization. Results: The study included 69 patients (median age 78 years; 54% female). RVEF decreased in 32 (46%), was stable in 27 (39%), and increased in 10 (15%). Compared with patients with decreased and stable RVEF, those with increased RVEF had lower baseline RVEF (43% vs. 52% and 50%, respectively, P = 0.007) and lower baseline RV to pulmonary artery coupling (0.78 vs. 1.00 and 1.18, P = 0.045). Pulmonary artery systolic pressure was lower in patients with stable RVEF (42 mmHg vs. 52 mmHg in decreased and 49 mmHg in increased RVEF group, P = 0.048). TR severity was significantly reduced in the decreased and stable RVEF groups (P < 0.001 for both) while it worsened in the increased RVEF group (P = 0.037). After T-TEER, effective RVEF rose significantly in decreased (30% to 35%) and stable (31% to 39%) groups (both P < 0.001) but tended to decline in the increased group (30% to 20%; P = 0.17). During a median follow-up of 1016 days, 16 patients died, and 15 were hospitalized for heart failure. Event rates were lowest in the stable RVEF group and highest in the increased RVEF group (log-rank P = 0.004). Conclusions: RV response to T-TEER is heterogeneous, mostly influenced by baseline RV function, RV-PA coupling and TR progression. Only a minority of patients exhibited an increase in RVEF post T-TEER, and these patients showed worsening TR and a poorer prognosis.