Outcomes Following Ischemic Stroke in Older Patients With CKD Stages 4 and 5: A Retrospective Cohort Study.

RATIONALE & OBJECTIVE: The associations between ischemic stroke and time to dialysis initiation and/or death in adults with late-stage chronic kidney disease (CKD) have not been explored. We sought to measure the rate and factors associated with stroke in CKD stages 4 and 5 (CKD4-5) and assess the association of stroke with initiation of dialysis and death.

STUDY DESIGN

Retrospective cohort.

SETTING & PARTICIPANTS: Patients with CKD4-5 in Medicare 2007 to 2014.

EXPOSURE OR PREDICTOR

Ischemic stroke in CKD4-5.

OUTCOMES

Initiation of maintenance dialysis or death.

ANALYTICAL APPROACH

Cox proportional hazard modeling assessed factors associated with ischemic stroke. A matched analysis (stroke/no stroke) estimated the cumulative incidence of incident kidney failure and death, treated as competing events. Simulations using a state transition model determined differences in expected time to kidney failure or death and death alone for patients with and without stroke with CKD5.

RESULTS

123,251 patients with CKD4 and 22,054 with CKD5 were identified. Mean ages were 81.0 and 79.2 years, respectively. Female sex (HRs of 1.21 [95% CI, 1.12-1.31] and 1.39 [95% CI, 1.04-1.86] for CKD4 and CKD5, respectively) and black race (HRs of 1.25 [95% CI, 1.12-1.39] and 1.12 [95% CI, 0.80-1.58] for CKD4 and CKD5, respectively) were factors associated with ischemic stroke. Rates for 30-day mortality were 13.3% and 18.8%, and for 1-year mortality, 40.0% and 38.2%. For patients with CKD5, kidney failure or death occurred an average of 3.6 months sooner for patients with an ischemic stroke, and death (irrespective of kidney failure), a mean of 24.3 months sooner.

LIMITATIONS

Study design cannot determine causality; lack of data for stroke severity.

CONCLUSIONS

Female sex and black race were associated with increased risk for stroke in CKD4 and CKD5. In CKD5, stroke was associated with a shorter time to kidney failure or death by nearly 4 months, and to death, by more than 2 years.