title: A prospective cohort study of patients with transient ischemic attack to identify high-risk clinical characteristics.
abstract: OBJECTIVE
  The occurrence of a transient ischemic attack (TIA) increases an individual's risk for subsequent stroke. The objectives of this study were to determine clinical features of patients with TIA associated with impending (≤7 days) stroke and to develop a clinical prediction score for impending stroke.
  
  
  METHODS
  We conducted a prospective cohort study at 8 Canadian emergency departments for 5 years. We enrolled patients with a new TIA. Our outcome was subsequent stroke within 7 days of TIA diagnosis.
  
  
  RESULTS
  We prospectively enrolled 3906 patients, of which 86 (2.2%) experienced a stroke within 7 days. Clinical features strongly correlated with having an impending stroke included first-ever TIA, language disturbance, longer duration, weakness, gait disturbance, elevated blood pressure, atrial fibrillation on ECG, infarction on computed tomography, and elevated blood glucose. Variables less associated with having an impending stroke included vertigo, lightheadedness, and visual loss. From this cohort, we derived the Canadian TIA Score which identifies the risk of subsequent stroke≤7 days and consists of 13 variables. This model has good discrimination with a c-statistic of 0.77 (95% confidence interval, 0.73-0.82).
  
  
  CONCLUSIONS
  Patients with TIA with their first TIA, language disturbance, duration of symptoms≥10 minutes, gait disturbance, atrial fibrillation, infarction on computed tomography, elevated platelets or glucose, unilateral weakness, history of carotid stenosis, and elevated diastolic blood pressure are at higher risk for an impending stroke. Patients with vertigo and no high-risk features are at low risk. The Canadian TIA Score quantifies the impending stroke risk following TIA.
authors.affiliation: From the Departments of Emergency Medicine (J.J.P., I.G.S.) and Epidemiology and Community Medicine (G.A.W.) and Division of Neurology (G.S.), University of Ottawa, Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada (J.J.P., J.S., I.G.S.); Departments of Emergency Medicine (M.L.A.S., H.E.M.) and Biomedical and Molecular Sciences (M.L.A.S.) and Division of Neurology (A.Y.J.), Queen's University, Kingston, Ontario, Canada; Department of Emergency Medicine, Université Laval, Quebec City, Quebec, Canada (M.É.); Divisions of Emergency Medicine (A.W.) and Neurology (M.S., W.J.O, D.J.S.), McMaster University, Hamilton, Ontario, Canada; and Department of Neurology, Hôpital de l'Enfant-Jesus, Quebec City, Quebec, Quebec, Canada (A.M., S.V.).
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Perry
authors.forename: Mukul
authors.initials: M
authors.lastname: Sharma
authors.forename: Marco L A
authors.initials: ML
authors.lastname: Sivilotti
authors.forename: Jane
authors.initials: J
authors.lastname: Sutherland
authors.forename: Andrew
authors.initials: A
authors.lastname: Worster
authors.forename: Marcel
authors.initials: M
authors.lastname: Émond
authors.forename: Grant
authors.initials: G
authors.lastname: Stotts
authors.forename: Albert Y
authors.initials: AY
authors.lastname: Jin
authors.forename: Wieslaw J
authors.initials: WJ
authors.lastname: Oczkowski
authors.forename: Demetrios J
authors.initials: DJ
authors.lastname: Sahlas
authors.forename: Heather E
authors.initials: HE
authors.lastname: Murray
authors.forename: Ariane
authors.initials: A
authors.lastname: MacKey
authors.forename: Steve
authors.initials: S
authors.lastname: Verreault
authors.forename: George A
authors.initials: GA
authors.lastname: Wells
authors.forename: Ian G
authors.initials: IG
authors.lastname: Stiell
mesh_terms: D000368:Aged; D002170:Canada; D015331:Cohort Studies; D003627:Data Interpretation, Statistical; D005260:Female; D005544:Forecasting; D006801:Humans; D002546:Ischemic Attack, Transient / Q000175:diagnosis* / Q000523:psychology; D007806:Language Disorders / Q000209:etiology; D008297:Male; D015999:Multivariate Analysis; D009460:Neurologic Examination; D017063:Outcome Assessment, Health Care; D011446:Prospective Studies; D012372:ROC Curve; D040841:Resource Allocation; D018570:Risk Assessment; D020521:Stroke / Q000453:epidemiology; D016896:Treatment Outcome
keywords: emergency medicine; stroke; transient ischemic attack