title: Blood biomarkers for the diagnosis of acute cerebrovascular diseases: a prospective cohort study.
abstract: BACKGROUND
  The diagnosis of stroke or TIA in the emergency department is difficult, though important for early treatment. Circulating biomarkers might improve upon clinical assessment at admission.
  
  
  METHODS
  We recruited symptomatic patients with suspected stroke or TIA and drew blood soon after admission. Each patient was assessed with the Face Arm Speech Test (FAST). We measured a panel of 15 circulating inflammatory, thrombotic, cardiac, and cerebral tissue damage biomarkers. Improvement in diagnostic performance was assessed by adding biomarkers to the FAST in logistic regression models to predict a final diagnosis of stroke or TIA (verified by expert review and imaging).
  
  
  RESULTS
  405 patients had suspected stroke: 285 with TIA or stroke (230 definite or probable ischemic stroke, 40 TIA, 15 hemorrhagic stroke) and 120 with other diagnoses. Only the markers t-PA and NT-proBNP were associated positively and significantly (p < 0.01) with a diagnosis of TIA or stroke. The FAST had a sensitivity of 82% (95% CI 78-87) and specificity of 38% (95% CI 29-46) for the diagnosis of TIA or stroke. No biomarker individually improved the sensitivity or specificity of the FAST. A model containing the FAST, age, systolic blood pressure, NT-proBNP and t-PA had a better sensitivity (88%, p < 0.006) and a better specificity (48%, p = 0.04) than the FAST test alone.
  
  
  CONCLUSIONS
  No single blood marker improved the diagnostic performance of a validated clinical stroke scale. Panels of biomarkers may marginally improve diagnosis, but their practicability is uncertain, and requires further study.
authors.affiliation: Division of Clinical Neurosciences, Western General Hospital, University of Edinburgh, Crewe Road, Edinburgh, UK. william.whiteley @ ed.ac.uk
authors.forename: William
authors.initials: W
authors.lastname: Whiteley
authors.forename: Joanna
authors.initials: J
authors.lastname: Wardlaw
authors.forename: Martin
authors.initials: M
authors.lastname: Dennis
authors.forename: Gordon
authors.initials: G
authors.lastname: Lowe
authors.forename: Ann
authors.initials: A
authors.lastname: Rumley
authors.forename: Naveed
authors.initials: N
authors.lastname: Sattar
authors.forename: Paul
authors.initials: P
authors.lastname: Welsh
authors.forename: Alison
authors.initials: A
authors.lastname: Green
authors.forename: Mary
authors.initials: M
authors.lastname: Andrews
authors.forename: Catriona
authors.initials: C
authors.lastname: Graham
authors.forename: Peter
authors.initials: P
authors.lastname: Sandercock
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D015331:Cohort Studies; D005260:Female; D006801:Humans; D002546:Ischemic Attack, Transient / Q000097:blood / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D020521:Stroke / Q000097:blood / Q000175:diagnosis*; D010959:Tissue Plasminogen Activator / Q000097:blood*
chemical_list: D015415:Biomarkers; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain; D010959:Tissue Plasminogen Activator