Abstract
OBJECTIVES: Whether patients with kidney failure who undergo cardiac surgery have a survival advantage with previous kidney transplantation is unclear. This study evaluated long-term outcomes after cardiac surgery for kidney transplant recipients and patients dependent on dialysis using national registries. METHODS: Probabilistic data linkage was undertaken between registries for the period 2010-2019. Time-to-event analyses were used to estimate the risk after cardiac surgery of (1) survival for kidney-replacement therapy recipients (n = 1250), and (2) graft survival for kidney transplant recipients (n = 225). Using cardiac surgery as a time-varying covariate, kidney graft survival was compared among the national contemporary kidney transplant population (n = 7934). RESULTS: Five-year survival probabilities after cardiac surgery for patients with kidney transplants and receiving dialysis were 70% (95% confidence interval [CI], 61%-76%) and 49% (95% CI, 45%-53%), respectively. The benefit for kidney transplantation persisted in a multivariable Cox regression model (reference: facility hemodialysis; adjusted hazard ratio [HR], 0.53; 95% CI, 0.37-0.74; P < .001). Five-year kidney graft survival probability after cardiac surgery was 60% (95% CI, 52%-68%) and was lower with stage 3 acute kidney injury (reference: none; adjusted HR, 2.61; 95% CI, 1.32-5.16; P = .006). Among the national contemporary kidney transplant recipient population, cardiac surgery was associated with an increased risk of graft loss (adjusted HR, 1.70; 95% CI, 1.07-2.74; P = .026). CONCLUSIONS: Among adults with kidney failure undergoing cardiac surgery, kidney transplant recipients experienced a long-term survival advantage compared with patients dependent on dialysis. Transplant recipients undergoing cardiac surgery had greater risk of graft loss than the national contemporary kidney transplant population.