Background: Cardiovascular (CV) disease is the leading cause of death in patients with end stage renal disease (ESRD) before and after renal transplantation. The optimum approach for identifying patients at prohibitive CV risk prior to transplant is unclear. Cardiac stress testing (CST) is commonly used in some centers and less so in others. We examined the patterns and predictors of CST prior to renal transplantation in patients with ESRD.
Methods: Data on patients with ESRD who underwent renal transplant from 2006-2013 and were covered by Medicare were obtained from the United States Renal Data System. Facilities with < 10 transplants were excluded. Patient and facility characteristics were compared between groups with and without CST using Student’s t-test and Pearson chi-square test for continuous and categorical variables, respectively. Patient and facility variables with P<0.10 were entered into a multivariable logistic regression model to identify predictors of CST. The variability in CST attributable to facility was described by the intraclass correlation (ICC).
Results: From 27,816 patients undergoing transplant, the final sample after exclusions was 24,694 patients from 217 facilities. Variability in CST across facilities is presented in the figure (figure 1, cardiac stress testing by facility). The ICC of 18.6% indicated that 18.6% of the variability in CST was attributable to the transplant center independent of clinical characteristics. The median odds ratio was 2.28, indicating that a patient moving to a facility with a higher rate of stress testing will be 2.28 times more likely to undergo CST. The only clinical factor associated with a greater likelihood of CST was a history of CAD (OR 2.66, 95% CI 2.47-2.88, P<0.001).
Conclusions: The frequency of CST prior to renal transplant varies substantially by transplant center after adjusting for clinical factors. Additional research is needed to define the role of CST prior to renal transplantation.