Excess Stroke Deaths in Kidney Transplant Recipients: A Retrospective Population-based Cohort Study Using Data Linkage

Background Kidney transplant recipients are thought to experience a high risk of stroke; however, little data exist. We aimed to compare the stroke deaths in kidney transplant recipients with the general population and identify risk factors for stroke death in kidney transplant recipients. Methods Cause of death was established using data linkage between the Australian and New Zealand Dialysis and Transplant Registry and national death registers: Australia, 1980-2013, and New Zealand, 1988-2012. We estimated standardized mortality ratios (SMR) and used competing risks models to identify risk factors. Subanalysis explored those with polycystic kidney disease. Results Among 17 628 kidney transplant recipients, there were 158 stroke deaths and 5126 nonstroke deaths in 175 084 person-years. Those aged 30-49 years experienced more stroke deaths than expected, especially women (SMR in females: 19.7 [95% confidence interval, 12.9-30.3] and males: 9.1 [95% confidence interval, 5.6-14.6]). Higher risk of stroke death was associated with older age at transplant, ever graft failure, earlier era of transplant, preexisting cerebrovascular disease, and no previous malignancy. Polycystic kidney disease did not result in different SMR. Conclusions Kidney transplant recipients had excess stroke deaths, particularly at younger ages and women. Preexisting cerebrovascular disease was a potentially modifiable risk factor for stroke death, suggesting further studies of secondary stroke prevention for kidney transplant recipients.