Background: Cardiorenal syndrome is frequent in patients referred for transcatheter tricuspid edge-to-edge repair (T-TEER). Risk factors associated with poor outcome in patients with renal dysfunction undergoing T-TEER are not well established.
Objective: This study aimed to assess the prognostic significance of cardiorenal syndrome on all-cause mortality after T-TEER for severe TR.
Methods: Consecutive patients with severe tricuspid regurgitation who underwent T-TEER between August 2020 and August 2025 were included and followed prospectively. Estimated glomerular filtration rate (eGFR) was calculated using the CKD-EPI 2021 equation. Patients were stratified according to the receiver-operator-characteristic (ROC)-derived eGFR cut-off (53 mL/min/1.73 m²). The primary outcome was all-cause mortality. The prognostic value of eGFR was evaluated by receiver-operator-characteristic analysis, Kaplan-Meier survival estimates, and Cox proportional-hazards regression. Risk factors for all-cause mortality in the cohort with impaired renal function were identified using LASSO-penalized logistic regression with cross-validated tuning parameter selection and multivariable Cox proportional hazards regression.
Results: A total of 226 patients (median age 81 ± 7 years, 59% female) with severe tricuspid regurgitation undergoing T-TEER were included. Median baseline eGFR was 52 mL/min/1.73 m², and 52% of patients had renal dysfunction defined by the ROC-derived threshold of 53 mL/min/1.73 m². During a median follow-up of 12 months, 58 patients (27%) deceased, with substantially higher mortality among patients with cardiorenal syndrome (35%) compared with those with preserved renal function (20%; p = 0.017). Kaplan–Meier survival analysis confirmed significantly reduced survival in patients with eGFR ≤ 53 mL/min/1.73 m² (log-rank p = 0.009). In this cohort, elevated NT-proBNP (HR 2.29, 95% CI 1.24–4.24, p = 0.008) and lower LVSWI (HR 0.52, 95% CI 0.28–0.99, p = 0.047) were independently associated with increased mortality. The model demonstrated good discrimination (C-index = 0.80 ± 0.04), and bootstrap resampling confirmed parameter stability.
Conclusions: Cardiorenal syndrome is frequent among T-TEER candidates and confers a higher risk of all-cause mortality. In patients with impaired renal function, NT-proBNP and the invasively derived LVSWI were the most relevant predictors of mortality, highlighting the interaction between renal status, myocardial performance, and outcome. Incorporating both renal and hemodynamic parameters into pre-procedural evaluation could refine prognostic stratification and guide therapeutic decision-making.
