Kidney impairment and outcomes in acute ischaemic stroke

Background: Chronic kidney disease (CKD) is associated with increased risk of stroke and mortality. Aims: To evaluate the clinical and imaging features and outcomes of patients with and without kidney impairment among t admitted for acute ischaemic stroke (AIS). Methods: AIS patients with brain magnetic resonance imaging (MRI) were included in the study. Kidney impairment was defined by an admission estimated glomerular filtration rate < 60 mL/min/1.73 m². Cerebral microbleeds (CMB) and white matter hyperintensities (WMH) were evaluated using the Microbleed Anatomical Rating Scale and Fazekas scales, respectively. Primary outcomes were defined by modified Rankin Scale (mRS) and discharge disposition. Multivariate logistic regression analysis was performed to evaluate factors associated with the presence of kidney impairment and poor discharge outcomes. Results: Of the 285 patients with AIS, 80 had kidney impairment on admission. Patients with kidney impairment were older (mean age ± standard deviation: 74.7 ± 12.9 vs 64.4 ± 13.8 years, P < 0.0001) and had more neurological deficits on National Institutes of Health Stroke Scale (NIHSS) score (median 8.5 vs 5, P = 0.02). In unadjusted analysis, patients with kidney impairment were less likely to have a good functional outcome (mRS 0–2: 36% vs 57%, P = 0.002) and good discharge outcome (home or inpatient rehabilitation: 68% vs 82%, P = 0.008). On multivariate analysis, kidney impairment was associated with higher NIHSS score (odds ratio (OR) = 1.04; 95% confidence interval (CI) = 1.002–1.08) and severe WMH (OR = 1.99; 95% CI = 1.06–3.77) suggestive of small vessel disease, but kidney impairment was not associated with poor discharge outcome (OR = 1.62; 95% CI = 0.75–3.53). Conclusion: Presence of kidney impairment at the time of stroke presentation, regardless of previous renal function, is associated with more neurological deficits and severe WMH on MRI.