Prognostic impact of renal function improvement following tricuspid transcatheter edge-to-edge repair: Insights from the EuroTR Registry

Background Tricuspid regurgitation (TR) and chronic kidney disease (CKD) frequently coexist, and renal function improvement has been observed following treatment with tricuspid transcatheter edge-to-edge repair (T-TEER). However, the prognostic relevance of such improvement remains unclear and large-scale data are scarce. Purpose This study aimed to investigate the incidence and prognostic impact of renal function improvement in patients with CKD undergoing T-TEER. Methods We analysed patients undergoing T-TEER for symptomatic TR in the multicentre, real-world EuroTR registry (European Registry of Transcatheter Repair for Tricuspid Regurgitation). Only patients with prevalent CKD (estimated glomerular filtration rate [eGFR] <60ml/min/1.73m2) with available eGFR at baseline and discharge were included. Patients were stratified according to the Kidney Disease: Improving Global Outcomes (KDIGO)-CKD stages (G3a: eGFR 45-59, G3b: 30-44, G4: 15-29, G5: <15 ml/min/1.73m2). Renal function improvement was defined as a ≥1 stage improvement from baseline to discharge. Associations between renal function improvement and 2-year outcomes (all-cause mortality and the composite of mortality or heart failure hospitalization [HFH]) were assessed using Kaplan-Meier analysis and Cox proportional hazard models. Predictors of renal function improvement were evaluated using logistic regression. Results A total of 903 patients with CKD undergoing T-TEER were included (G3a: n=287, G3b: n=386, G4: n=184, G5: n=46). Renal function improvement occurred in 35.5% (n=321), whereas 64.5% (n=582) showed no improvement (Figure 1). Improvement rates were numerically higher among patients achieving a 3-grade TR reduction (44.7%) compared with those with 2- or 1-grade reduction (34.9% and 36.2%, respectively, p=0.35). In Kaplan-Meier analysis, 2-year all-cause mortality was 26.4% in patients with vs. 35.6% in those without renal function improvement (p=0.060, Figure 1). Corresponding rates for the composite endpoint were 44.2% and 53.7%, respectively (p = 0.12). In multivariable Cox regression, renal function improvement was independently associated with a lower risk of all-cause mortality (HR 0.71, 95% CI 0.52-0.97, p=0.030) and the composite endpoint (HR 0.75, 95% CI 0.59-0.96, p=0.020) at 2 years. Lower body mass index was independently associated with renal function improvement (OR 0.97, 95% CI 0.94-1.00, p=0.027). Conclusions Renal function improvement occurs in more than one third of patients with TR and CKD undergoing T-TEER and is associated with more favourable clinical outcomes at 2-years. These findings emphasize the potential impact of TR treatment in patients with advanced CKD, warranting further investigation into renal function as a therapeutic target and prognostic surrogate after T-TEER.