Nationwide 5-year outcomes in U.S. dialysis patients with failed bioprosthetic surgical AVR: valve-in-valve TAVR versus redo surgery

Background Bioprosthetic surgical AVR (bioSAVR) often requires reintervention once structural valve degeneration occurs1. In dialysis, accelerated calcification leads to markedly earlier bioprosthesis failure2. No study has ever focused on the optimal management of failed bioprosthetic aortic valves in dialysis, and current ESC/EACTS and ACC/AHA guidelines do not provide procedure-specific recommendations on redo AVR in dialysis. Purpose To address this knowledge gap by comparing outcomes of redo SAVR vs Valve-in-Valve TAVR in dialysis patients in a nationwide, real-world cohort. Methods All patients on dialysis in the USA with prior bioSAVR undergoing isolated second-time AVR over 10 years (2011-2020) were included from the United States Renal Data System (USRDS) national database and categorized by procedure: redo SAVR (RS) or ViV TAVR (TI). Exclusion criteria: infective endocarditis and any concomitant or planned cardiac interventions. Follow-up data was 100% complete until either death or kidney transplant. Kaplan-Meier (KM) estimates assessed all-cause mortality by procedure and logistic regression identified factors associated with in-Hospital (In-H) mortality. Analyses were repeated after propensity score matching (PSM) by 16 baseline characteristics. Results 729 patients were included (median age 67y; 64% male): 330 RS and 399 TI. Before PSM, the cohorts differed significantly in several characteristics: age (p<0.01), CKD aetiology (p=0.04), dyslipidaemia (p<0.01), COPD (p=0.03) and a-fib/flutter (p=0.02). After PSM (Figure 1), 269 patient pairs were created with excellent balance across all demographics (all p>0.05 and SMD<0.1). TI patients had lower In-H all-cause mortality both before (13% RS vs 5% TI,p<0.01) and after (15% RS vs 3% TI,p<0.01) matching. Multivariable logistic regression demonstrated that TI was independently associated with lower odds of In-H mortality compared to RS (OR 0.29, 95% CI 0.16–0.52; p<0.01). However, no difference in 1-year mortality was observed (unmatched 28% RS vs 34% TI,p=0.12; matched 29% RS vs 31% TI,p=0.71). No differences in In-H stroke, ECMO or major bleeding were recorded; RS patients had greater ICU stays (median days 5.0 RS vs 1.0 TI,p<0.01) and >96h ventilation (13% RS vs 4% TI,p<0.01). 18 (5.5%) RS and 12 (3.0%) TI patients (p=0.14) underwent kidney transplant during follow-up. The statistical significance of all findings remained consistent after PSM (Figure 1). Both unadjusted and matched KM curves demonstrated higher 5-year mortality in TI compared with RS patients (p<0.01;Figure 2). Conclusions In dialysis patients with degenerated bioprosthetic aortic valves, ViV TAVR is independently associated with fewer short-term adverse events, but higher long-term mortality, compared with redo SAVR. ViV TAVR may be preferred in dialysis patients with limited life expectancy or prohibitive surgical risk, whereas redo SAVR may be favoured in younger, surgically eligible patients.