Background: The role of right ventricular (RV) function in patients undergoing transcatheter tricuspid valve repair (TTVR) for severe tricuspid regurgitation (TR) is poorly understood. We aimed to assess the role of RV function, on the composite outcome of all-cause mortality and heart failure rehospitalisation, as well as to identify subgroups of RV-failure stages in patients undergoing TTVR.

Methods: Patients undergoing TTVR for isolated severe TR between 2016 and 2020 were included. Global RV-dysfunction was defined as cardiac magnetic resonance imaging (CMRi) derived RVEF ≤45% and longitudinal RV-dysfunction was defined as tricuspid annular plane systolic excursion (TAPSE) <17 mm. Patients were further stratified into three stage of RV-failure: stage I with preserved global- and longitudinal-function, stage II with preserved global- but reduced longitudinal-function and stage III with decreased global- and longitudinal-function. CMRi feature tracking strain analysis was performed to distinguish RV-contraction patterns according to RV-failure stages. The primary outcome was a composite of all-cause mortality or first heart failure hospitalisation.

Results: Overall, 79 patients (median age 79, 51% female) were included in the current study of whom 18 presented with global- (23%) and 40 with longitudinal-dysfunction (51%) of the RV. Within a median follow-up of 362 (IQR 182, 369) days the composite outcome occurred in 22 patients. While global RV-dysfunction was independently predictive for the occurrence of the primary outcome (HR 6.6, 95%CI 2.8, 15.8), longitudinal RV-dysfunction showed no association with the primary outcome (HR 1.3, 95%CI 0.55, 3.1). As compared to stage I RV-failure patients with stage II RV-failure exhibited increased circumferential strain, resulting in a preservation of RVEF despite diminished longitudinal strain. Patients in stage III RV failure exhibited both diminished longitudinal as well circumferential strain, resulting in an impaired RVEF. Alongside increasing stages of RV failure PA pressure increased (Table 1). Notably, only patients with stage III RV failure showed impaired survival (Fig. 1)

Conclusion: Global RV-dysfunction is an independent predictor of cardiovascular outcome among patients undergoing TTVR. Patients undergoing TTVR can be stratified into three stages of RV failure where a loss of longitudinal function can be compensated by increasing circumferential function, preserving RVEF and favourable outcome.