Chronic kidney disease and survival of patients with tricuspid regurgitation

Introduction Chronic kidney disease (CKD) patients are under-represented in clinical trials examining transcatheter interventions for tricuspid regurgitation (TR). The purpose of the current analysis was to investigate how CKD modifies the association of severe TR with overall survival. Methods Consecutive echocardiographic reports linked to clinical data from the largest medical center in Israel (2007-2022) were reviewed. Patients were dichotomized into four mutually exclusive TR groups (none/trivial, mild, moderate and severe), following by stratification according to CKD stage classification. The primary outcome was all-cause mortality. Kaplan Meier, Multivariate Cox regression and interaction analysis models were applied. Results Final study population included 78,147 patients with a median age of 67 (IQR: 55-78 years), 2,989 (4%) of whom had severe TR. There were 19,910 (25%) patients with estimated glomerular filtration rate [eGFR] < 60 mL/min/1.73 m2, 14,359 (18%) with eGFR between 30-60 and 5,551 (7%) with eGFR <30. During a median follow-up period of 4 years (IQR: 1-7 years), 28,112 patients (36%) died. Kaplan-Meier survival analysis demonstrated an increased risk of death with both increasing severity of TR and/or CKD grade (log-rank p<.001 for both). Multivariate Cox analysis with adjustment for age, sex, left heart disease and pulmonary pressures demonstrated that compared to the none/trivial group, patients with severe TR were 38% more likely to die during follow up (95% CI 1.30-1.47, p<.001). The association of tricuspid regurgitation with poor survival was CKD-dependent, such that in the eGFR>60 group severe TR was associated with 19% increased risk of death, whereas among patients with eGFR<60 the risk was significantly higher and reached 34% in the same multivariate model (p for interaction <.001). Interestingly, the modification effect of CKD was mediated by RV function, such that the interaction analysis was no longer significant when RV function was incorporated into the multivariate model. Sub analysis limited to patients with isolated TR yielded consisted results. Conclusions While the association of severe TR with poor survival is consistent across all CKD groups, it is more pronounced among patients with advanced CKD. This association may be modulated through right ventricular function. When examining data and outcome of tricuspid clinical trials , special emphasis should be given to CKD status.