Abstract 82: Diagnostic Accuracy of Plasma Glial Fibrillary Acidic Protein (GFAP) for the Differentiation between Intracerebral Hemorrhage and Cerebral Ischemia in Patients with Symptoms of Acute Stroke
Background: Explorative studies have identified glial fibrillary acidic protein (GFAP) as a blood biomarker candidate indicating intracerebral hemorrhage (ICH) in patients with symptoms suspicious of acute stroke. GFAP is released rapidly in the presence of an expanding intracerebral bleeding, whereas a more gradual release occurs in case of cerebral ischemia. This study focused on determining the diagnostic accuracy of plasma GFAP in a prospective multicenter approach.
Methods: Within a one-year recruitment period, patients suspicious of having acute (i.e. symptom onset <4.5 hours before hospital admission) hemispheric stroke were prospectively included in 14 stroke centers in Germany and Switzerland. A single blood sample was derived at hospital admission. GFAP plasma concentrations were measured using an electrochemiluminometric immunoassay. The final diagnosis was established at hospital discharge, classified as ICH, ischemic stroke, or stroke mimic, respectively.
Results: N=205 patients were included (39 with ICH, 163 with ischemic stroke, three stroke mimics). GFAP concentrations were markedly elevated in patients with ICH as compared to patients with ischemic stroke (median [interquartile range] 1.91µg/l [0.41-17.66] vs. 0.08 [0.02-0.14], p<0.001). Diagnostic accuracy of GFAP for differentiating ICH from ischemic stroke and stroke mimics was high (AUC=0.915 [95%CI 0.847-0.982], p<0.001). A GFAP cut-point of 0.29µg/l provided a sensitivity of 0.84 and a specificity of 0.96 for differentiating ICH from ischemic stroke and stroke mimics.
Conclusions: A GFAP plasma test performed within 4.5 hours of symptom onset is accurate in differentiating between ICH and ischemic stroke. If applied as a point-of-care measure in the pre-hospital setting, it would open the gate towards an optimized triage and a hyperacute treatment of patients with symptoms suspicious for acute stroke.
- © 2012 by American Heart Association, Inc.