title: Discriminative capacity of biomarkers for acute stroke in the emergency department.
abstract: BACKGROUND
  Acute ischemic stroke remains largely a clinical diagnosis.
  
  
  OBJECTIVE
  To assess the potential of several biomarkers to distinguish acute ischemic stroke from mimics in the emergency department (ED).
  
  
  METHODS
  In this prospective study, 63 patients with suspected acute stroke were enrolled. Blood samples were collected at ED presentation and assayed for B-type natriuretic peptide, C-reactive protein (CRP), matrix metalloproteinase 9 (MMP-9), D-dimer, and protein S100B. Final diagnosis of stroke was rendered by blinded independent stroke experts after review of all clinical, imaging, and conventional laboratory data during admission. Logistic regression and bootstrapping models were used to evaluate the association between biomarker values and acute stroke.
  
  
  RESULTS
  Thirty-four patients had a final diagnosis of stroke and 29 with mimics. The initial ED values of CRP, MMP-9, and S100B (C-indices of 0.808, 0.811, and 0.719, respectively) and the National Institutes of Health Stroke Scale (NIHSS) (C-index 0.887) predicted acute cerebral ischemia. CRP levels added discriminative value over clinical variables alone in the diagnosis of stroke. When the levels of CRP were added to the NIHSS, the combination was highly predictive of stroke (bootstrap mean C-index 0.951, 90% Confidence Interval 0.903-0.991, likelihood test p = 0.004).
  
  
  CONCLUSIONS
  Biomarker testing with CRP and potentially MMP-9 and S100B, may add valuable and time-sensitive diagnostic information in the early evaluation of patients with suspected stroke in the ED. Future prospective evaluations are necessary to validate the diagnostic capability of these biomarkers for acute ischemic stroke in the ED before they should be considered for use in clinical practice.
authors.affiliation: Department of Emergency Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599-7594, USA.
authors.forename: Seth W
authors.initials: SW
authors.lastname: Glickman
authors.forename: Samantha
authors.initials: S
authors.lastname: Phillips
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Anstrom
authors.forename: Daniel T
authors.initials: DT
authors.lastname: Laskowitz
authors.forename: Charles B
authors.initials: CB
authors.lastname: Cairns
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis; D004636:Emergency Service, Hospital; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis; D006801:Humans; D016015:Logistic Models; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000097:blood; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood; D009414:Nerve Growth Factors / Q000097:blood; D011446:Prospective Studies; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins / Q000097:blood; D012680:Sensitivity and Specificity; D020521:Stroke / Q000097:blood / Q000175:diagnosis*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D005338:Fibrin Fibrinogen Degradation Products; D009414:Nerve Growth Factors; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; C579160:S100B protein, human; C036309:fibrin fragment D; D020097:Natriuretic Peptide, Brain; D002097:C-Reactive Protein; D020780:Matrix Metalloproteinase 9