Variations in the risk for cerebrovascular events after kidney transplant compared with experience on the waiting list and after graft failure

Abstract

Background and objectives: This study examined the risks, predictors, and mortality implications of cerebrovascular disease events after kidney transplantation in a national cohort.

Design, setting, participants, & measurements: This analysis used United States Renal Data System registry data to study retrospectively Medicare-insured kidney transplant candidates (n = 51,504), recipients (n = 29,614), and recipients with allograft failure (n = 2954) in 1995 through 2002. New-onset cerebrovascular disease events including ischemic stroke, hemorrhagic stroke, and transient ischemic attacks were ascertained from billing records, and participants were followed until Medicare-end or December 31, 2002. Multivariable survival analysis was used to compare cerebrovascular disease event incidence and risk profiles among the study samples.

Results: The cumulative, 3-yr incidence of de novo cerebrovascular disease events after transplantation was 6.8% and was lower than adjusted 3-yr estimates of 11.8% on the waiting list and 11.2% after graft loss. In time-dependent regression, transplantation predicted a 34% reduction in subsequent, overall cerebrovascular disease events risk compared with remaining on the waiting list, whereas risk for cerebrovascular disease events increased >150% after graft failure. Similar relationships with transplantation and graft loss were observed for each type of cerebrovascular disease event. Smoking was a potentially preventable correlate of posttransplantation cerebrovascular disease events. Women were not protected. All forms of cerebrovascular disease event diagnoses after transplantation predicted increased mortality.

Conclusions: Along with known benefits for cardiac complications, transplantation with sustained graft function seems to reduce risk for vascular disease events involving the cerebral circulation.

Figure 1.

Observed incidence of new-onset cerebrovascular events on the kidney transplant waiting list, after transplantation, and after allograft failure. Incidence computed by the Kaplan-Meier method. Waiting list incidence was censored at transplantation; incidence after transplantation was censored at graft failure. CVE, cerebrovascular disease event.

Figure 2.

Incidence of new-onset cerebrovascular events by kidney transplant status, with adjustment to the average characteristics of the study sample that underwent transplantation. Waiting list incidence was censored at transplantation; incidence after transplantation was censored at graft failure. Incidence estimates on the waiting list and after transplantation were computed by Cox regression, with adjustment of significant event correlates to the average values of the study sample that underwent transplantation.