Association between white matter lesions, renal dysfunction and functional outcome in ischemic stroke patients

Background and Purpose: White matter lesions (WMLs) are common in patients with renal dysfunction and associated with functional outcome after stroke. We sought to determine whether WMLs and decreased estimated glomerular filtration rate (eGFR) are indicative of stroke functional outcome at 1 year. Methods: A retrospective analysis was performed in the Berlin “Cream& Sugar” cohort study (NCT 01378468) using data between Jan. 2009 to Mar. 2012. Patients over 18 years of age with first-ever acute ischemic stroke and with completed follow-up, eGFR and MRI data were included. Initial severity of stroke was assessed using National Institutes of Health Stroke Scale (NIHSS). Serum creatinine was obtained 3-7 days following stroke onset. eGFR was calculated based on the Modification of diet in renal disease (MDRD) formula. Severity of WMLs was assessed on FLAIR or T2-weighted sequences using the Fazekas visual rating scales. Functional outcome was assessed via telephone interview at 1 year using the modified Rankin Scale (mRS). Age, gender, NIHSS at admission, eGFR and WMLs were included in a binary logistic regression model. Results: 160 first acute ischemic stroke patients (median age 66 years, IQR 52-73, male 63.1%, median NIHSS at admission 2, IQR 1-4) were included. A cross-table analysis showed that eGFR < 90 mL/min/1.73m2 (OR 2.30, 95% CI 1.17-4.52, p = 0.014) was associated with the presence of WMLs (Fazekas score 1-3). A binary logistic regression analysis showed that eGFR 30-60 mL/min/1.73m2 (OR 7.86, 95% CI 1.77-34.83, p = 0.007), moderate-to-severe WMLs (Fazekas 2-3) (OR 2.22, 95% CI 1.03-4.77, p = 0.042) and NIHSS ≥ 5 (OR 6.77, 95% CI 2.06-22.23, p = 0.002) were independently associated with unfavourable functional outcome (mRS score ≥ 2) after acute ischemic stroke at 1 year. Conclusion: Our data suggested that renal dysfunction was associated with WMLs; both of them were independently associated with functional outcome after acute ischemic stroke at 1 year. Assessment of renal dysfunction and WMLs in acute stroke patients may be helpful to predict prognosis.