Abstract 3263: Cystatin C is Associated with Early Functional Outcome in Acute Stroke Patients

Abstract

Background: Cystatin C, a competitive inhibitor of lysosomal cysteine protease, is regarded as a sensitive marker of kidney dysfunction. Lower estimated glomerular filtration rate (eGFR) was associated with poor prognosis and all cause of mortality in stroke patients. Cystatin C was a more sensitive and accurate marker to detect subclinical kidney dysfunction, compared to creatinine, or creatinine based eGFR. We evaluated whether Cystatin C would predict functional outcome, independent of eGFR level in ischemic stroke. Methods: We evaluate consecutive patients with acute stroke who were admitted to Seoul National University Hospital between January 2008 and May 2011. We defined the unfavorable outcome group as containing each patient with a discharge mRS score of 1 with admission NIHSS score of 0 to 7, a discharge mRS score of 2 with admission NIHSS score 8 to 14, or a discharge mRS score of ≥3 with admission NIHSS score 15. Results: Among the total patients, 544(76.2%) patients had unfavorable outcome at discharge. Participants with unfavorable outcome tended to be female, older and to have higher Cystatin C, CRP, fibrinogen and Hb A1c concentrations. The proportion of patient with unfavorable outcome was gradually increased according to the cystatin C quartile. Compared to the lowest quartile of Cystatin C (47.2<nmol/L), higher quartiles (47.2 -54.7, 54.7-65.7, 65.7≥nmol/L) were likely to have a higher chance of unfavorable outcome [adjusted OR (95%CI), 1.55(0.73-3.31), 2.66 (1.21-5.87) and 2.84(1.15-7.09)] after adjusting for age, diabetes, Hb A1c, fibrinogen, CRP, NIHSS scale on admission, hemorrhagic transformation, IV thrombolytic treatment. In contrast, eGFR did not show any significant association with unfavorable outcome. Compared to the lowest category of eGFR (≥60 ml/min/1.73m2), higher categories (45.0- 60.0, 15.0-45.0, ≤15.0 ml/min/1.73m2) did not show significant association with unfavorable outcome. Conclusions: An increased level of Cystatin C was associated with functional outcome in stroke patients. Cystatin C may be a potent predictor to predictor of functional outcome after ischemic stroke.