Influence of Chronic Kidney Disease on Mortality After Acute Ischemic Stroke

Jang, Il Mi; Lee, Kyung Bok; Roh, Hakjae; Ahn, Moo Young

Abstract

BACKGROUND: Chronic kidney disease (CKD) is known to be associated with atherosclerosis and silent small-vessel occlusion, but there is scant information regarding the association between CKD and acute stroke. The aim of this study was to establish whether CKD influences the outcome and mortality rate after acute ischemic stroke.
METHODS
From January 2005 to June 2008, patients with CKD and with normal kidney function were identified from the entire population of patients presenting with acute ischemic strokes at Soonchunhyang university hospital. We analyzed the baseline demographics, risk factors, stroke severity, functional outcome, mortality rate, and the prognostic factors affecting mortality in the two groups, and investigated the causes of death.
RESULTS
Totals of 541 patients with normal kidney function (age 67.0/12.6 years; mean/SD) and 66 patients with CKD (age 70.8/11.9 years) were recruited. Hypertension and diabetes were more prevalent in the CKD group. National Institutes of Health Stroke Survey scores at admission (8.3/8.5 vs 5.5/6.0, p=0.001) and Modified Rankin Scale (mRS) scores at discharge (2.32/1.5 vs 1.92/1.5, p=0.067) were higher in the CKD group than in that with normal kidney function. Patients with CKD had a higher case-fatality rate (median survival time 13.9/13.6 months) than those without CKD (median survival time 19.2/13.2 months) and CKD was an independent prognostic factor for mortality after acute ischemic stroke. Cox proportional hazard analysis leukocytosis (hazard ratio, HR=4.46; 95% confidence interval, CI=1.28-15.52), high cardioembolic risk (HR=7.68; 95% CI=1.59-37.08), and poor (mRS> or =3) functional outcome at discharge (HR=8.67, 95% CI=2.19-34.33) were significant influencing factors on mortality in the CKD group.
CONCLUSIONS
Compared with the normal kidney function condition, CKD is associated with a higher mortality after acute ischemic stroke. Leukocytosis, high cardioembolic risk, and poor functional outcome may be important prognostic factors of mortality from acute ischemic stroke with CKD.