title: Computed tomography identifies patients at high risk for stroke after transient ischemic attack/nondisabling stroke: prospective, multicenter cohort study.
abstract: OBJECTIVE
  Ischemia on computed tomography (CT) is associated with subsequent stroke after transient ischemic attack. This study assessed CT findings of acute ischemia, chronic ischemia, or microangiopathy for predicting subsequent stroke after transient ischemic attack.
  
  
  METHODS
  This prospective cohort study enrolled patients with transient ischemic attack or nondisabling stroke that had CT scanning within 24 hours. Primary outcome was subsequent stroke within 90 days. Secondary outcomes were stroke at ≤2 or >2 days. CT findings were classified as ischemia present or absent and acute or chronic or microangiopathy. Analysis used Fisher exact test and multivariate logistic regression.
  
  
  RESULTS
  A total of 2028 patients were included; 814 had ischemic changes on CT. Subsequent stroke rate was 3.4% at 90 days and 1.5% at ≤2 days. Stroke risk was greater if baseline CT showed acute ischemia alone (10.6%; P=0.002), acute+chronic ischemia (17.4%; P=0.007), acute ischemia+microangiopathy (17.6%; P=0.019), or acute+chronic ischemia+microangiopathy (25.0%; P=0.029). Logistic regression found acute ischemia alone (odds ratio [OR], 2.61; 95% confidence interval [CI[, 1.22-5.57), acute+chronic ischemia (OR, 5.35; 95% CI, 1.71-16.70), acute ischemia+microangiopathy (OR, 4.90; 95% CI, 1.33-18.07), or acute+chronic ischemia+microangiopathy (OR, 8.04; 95% CI, 1.52-42.63) was associated with a greater risk at 90 days, whereas acute+chronic ischemia (OR, 10.78; 95% CI, 2.93-36.68), acute ischemia+microangiopathy (OR, 8.90; 95% CI, 1.90-41.60), and acute+chronic ischemia+microangiopathy (OR, 23.66; 95% CI, 4.34-129.03) had greater risk at ≤2 days. Only acute ischemia (OR, 2.70; 95% CI, 1.01-7.18; P=0.047) was associated with a greater risk at >2 days.
  
  
  CONCLUSIONS
  In patients with transient ischemic attack/nondisabling stroke, CT evidence of acute ischemia alone or acute ischemia with chronic ischemia or microangiopathy was associated with increased subsequent stroke risk within 90 days.
authors.affiliation: From the Department of Pathology and Laboratory Medicine (J.K.W.), Ottawa Hospital Health Research Institute (J.K.W., J.J.P., D.D., I.G.S.), Department of Emergency Medicine (J.J.P., I.G.S.), Department of Epidemiology and Community Medicine (G.A.W.), and Division of Neurology (D.D., G.S.), University of Ottawa, Ottawa, Ontario, Canada; Department of Emergency Medicine and of Pharmacology and Toxicology (M.L.A.S.), Department of Neurology (A.Y.J.), and Department of Emergency Medicine (H.M.), Queen's University, Kingston, Ontario, Canada; Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada (J.S.); Division of Emergency Medicine (A.W.), Division of Neurology (W.J.O., D.J.S.), and Population Health Research Institute (M.S.), Department of Neurology, McMaster University, Hamilton, Ontario, Canada; Department of Emergency Medicine, Université Laval, Quebec, Quebec, Canada (M.É.); and Department of Neurology, Hôpital de l'Enfant-Jesus, Quebec City, Quebec, Canada (A.M., S.V.).
authors.forename: Jason K
authors.initials: JK
authors.lastname: Wasserman
authors.affiliation: From the Department of Pathology and Laboratory Medicine (J.K.W.), Ottawa Hospital Health Research Institute (J.K.W., J.J.P., D.D., I.G.S.), Department of Emergency Medicine (J.J.P., I.G.S.), Department of Epidemiology and Community Medicine (G.A.W.), and Division of Neurology (D.D., G.S.), University of Ottawa, Ottawa, Ontario, Canada; Department of Emergency Medicine and of Pharmacology and Toxicology (M.L.A.S.), Department of Neurology (A.Y.J.), and Department of Emergency Medicine (H.M.), Queen's University, Kingston, Ontario, Canada; Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada (J.S.); Division of Emergency Medicine (A.W.), Division of Neurology (W.J.O., D.J.S.), and Population Health Research Institute (M.S.), Department of Neurology, McMaster University, Hamilton, Ontario, Canada; Department of Emergency Medicine, Université Laval, Quebec, Quebec, Canada (M.É.); and Department of Neurology, Hôpital de l'Enfant-Jesus, Quebec City, Quebec, Canada (A.M., S.V.). jperry@ohri.ca.
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Perry
authors.affiliation: From the Department of Pathology and Laboratory Medicine (J.K.W.), Ottawa Hospital Health Research Institute (J.K.W., J.J.P., D.D., I.G.S.), Department of Emergency Medicine (J.J.P., I.G.S.), Department of Epidemiology and Community Medicine (G.A.W.), and Division of Neurology (D.D., G.S.), University of Ottawa, Ottawa, Ontario, Canada; Department of Emergency Medicine and of Pharmacology and Toxicology (M.L.A.S.), Department of Neurology (A.Y.J.), and Department of Emergency Medicine (H.M.), Queen's University, Kingston, Ontario, Canada; Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada (J.S.); Division of Emergency Medicine (A.W.), Division of Neurology (W.J.O., D.J.S.), and Population Health Research Institute (M.S.), Department of Neurology, McMaster University, Hamilton, Ontario, Canada; Department of Emergency Medicine, Université Laval, Quebec, Quebec, Canada (M.É.); and Department of Neurology, Hôpital de l'Enfant-Jesus, Quebec City, Quebec, Canada (A.M., S.V.).
authors.forename: Marco L A
authors.initials: ML
authors.lastname: Sivilotti
authors.affiliation: From the Department of Pathology and Laboratory Medicine (J.K.W.), Ottawa Hospital Health Research Institute (J.K.W., J.J.P., D.D., I.G.S.), Department of Emergency Medicine (J.J.P., I.G.S.), Department of Epidemiology and Community Medicine (G.A.W.), and Division of Neurology (D.D., G.S.), University of Ottawa, Ottawa, Ontario, Canada; Department of Emergency Medicine and of Pharmacology and Toxicology (M.L.A.S.), Department of Neurology (A.Y.J.), and Department of Emergency Medicine (H.M.), Queen's University, Kingston, Ontario, Canada; Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada (J.S.); Division of Emergency Medicine (A.W.), Division of Neurology (W.J.O., D.J.S.), and Population Health Research Institute (M.S.), Department of Neurology, McMaster University, Hamilton, Ontario, Canada; Department of Emergency Medicine, Université Laval, Quebec, Quebec, Canada (M.É.); and Department of Neurology, Hôpital de l'Enfant-Jesus, Quebec City, Quebec, Canada (A.M., S.V.).
authors.forename: Jane
authors.initials: J
authors.lastname: Sutherland
authors.affiliation: From the Department of Pathology and Laboratory Medicine (J.K.W.), Ottawa Hospital Health Research Institute (J.K.W., J.J.P., D.D., I.G.S.), Department of Emergency Medicine (J.J.P., I.G.S.), Department of Epidemiology and Community Medicine (G.A.W.), and Division of Neurology (D.D., G.S.), University of Ottawa, Ottawa, Ontario, Canada; Department of Emergency Medicine and of Pharmacology and Toxicology (M.L.A.S.), Department of Neurology (A.Y.J.), and Department of Emergency Medicine (H.M.), Queen's University, Kingston, Ontario, Canada; Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada (J.S.); Division of Emergency Medicine (A.W.), Division of Neurology (W.J.O., D.J.S.), and Population Health Research Institute (M.S.), Department of Neurology, McMaster University, Hamilton, Ontario, Canada; Department of Emergency Medicine, Université Laval, Quebec, Quebec, Canada (M.É.); and Department of Neurology, Hôpital de l'Enfant-Jesus, Quebec City, Quebec, Canada (A.M., S.V.).
authors.forename: Andrew
authors.initials: A
authors.lastname: Worster
authors.affiliation: From the Department of Pathology and Laboratory Medicine (J.K.W.), Ottawa Hospital Health Research Institute (J.K.W., J.J.P., D.D., I.G.S.), Department of Emergency Medicine (J.J.P., I.G.S.), Department of Epidemiology and Community Medicine (G.A.W.), and Division of Neurology (D.D., G.S.), University of Ottawa, Ottawa, Ontario, Canada; Department of Emergency Medicine and of Pharmacology and Toxicology (M.L.A.S.), Department of Neurology (A.Y.J.), and Department of Emergency Medicine (H.M.), Queen's University, Kingston, Ontario, Canada; Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada (J.S.); Division of Emergency Medicine (A.W.), Division of Neurology (W.J.O., D.J.S.), and Population Health Research Institute (M.S.), Department of Neurology, McMaster University, Hamilton, Ontario, Canada; Department of Emergency Medicine, Université Laval, Quebec, Quebec, Canada (M.É.); and Department of Neurology, Hôpital de l'Enfant-Jesus, Quebec City, Quebec, Canada (A.M., S.V.).
authors.forename: Marcel
authors.initials: M
authors.lastname: Émond
authors.affiliation: From the Department of Pathology and Laboratory Medicine (J.K.W.), Ottawa Hospital Health Research Institute (J.K.W., J.J.P., D.D., I.G.S.), Department of Emergency Medicine (J.J.P., I.G.S.), Department of Epidemiology and Community Medicine (G.A.W.), and Division of Neurology (D.D., G.S.), University of Ottawa, Ottawa, Ontario, Canada; Department of Emergency Medicine and of Pharmacology and Toxicology (M.L.A.S.), Department of Neurology (A.Y.J.), and Department of Emergency Medicine (H.M.), Queen's University, Kingston, Ontario, Canada; Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada (J.S.); Division of Emergency Medicine (A.W.), Division of Neurology (W.J.O., D.J.S.), and Population Health Research Institute (M.S.), Department of Neurology, McMaster University, Hamilton, Ontario, Canada; Department of Emergency Medicine, Université Laval, Quebec, Quebec, Canada (M.É.); and Department of Neurology, Hôpital de l'Enfant-Jesus, Quebec City, Quebec, Canada (A.M., S.V.).
authors.forename: Albert Y
authors.initials: AY
authors.lastname: Jin
authors.affiliation: From the Department of Pathology and Laboratory Medicine (J.K.W.), Ottawa Hospital Health Research Institute (J.K.W., J.J.P., D.D., I.G.S.), Department of Emergency Medicine (J.J.P., I.G.S.), Department of Epidemiology and Community Medicine (G.A.W.), and Division of Neurology (D.D., G.S.), University of Ottawa, Ottawa, Ontario, Canada; Department of Emergency Medicine and of Pharmacology and Toxicology (M.L.A.S.), Department of Neurology (A.Y.J.), and Department of Emergency Medicine (H.M.), Queen's University, Kingston, Ontario, Canada; Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada (J.S.); Division of Emergency Medicine (A.W.), Division of Neurology (W.J.O., D.J.S.), and Population Health Research Institute (M.S.), Department of Neurology, McMaster University, Hamilton, Ontario, Canada; Department of Emergency Medicine, Université Laval, Quebec, Quebec, Canada (M.É.); and Department of Neurology, Hôpital de l'Enfant-Jesus, Quebec City, Quebec, Canada (A.M., S.V.).
authors.forename: Wieslaw J
authors.initials: WJ
authors.lastname: Oczkowski
authors.affiliation: From the Department of Pathology and Laboratory Medicine (J.K.W.), Ottawa Hospital Health Research Institute (J.K.W., J.J.P., D.D., I.G.S.), Department of Emergency Medicine (J.J.P., I.G.S.), Department of Epidemiology and Community Medicine (G.A.W.), and Division of Neurology (D.D., G.S.), University of Ottawa, Ottawa, Ontario, Canada; Department of Emergency Medicine and of Pharmacology and Toxicology (M.L.A.S.), Department of Neurology (A.Y.J.), and Department of Emergency Medicine (H.M.), Queen's University, Kingston, Ontario, Canada; Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada (J.S.); Division of Emergency Medicine (A.W.), Division of Neurology (W.J.O., D.J.S.), and Population Health Research Institute (M.S.), Department of Neurology, McMaster University, Hamilton, Ontario, Canada; Department of Emergency Medicine, Université Laval, Quebec, Quebec, Canada (M.É.); and Department of Neurology, Hôpital de l'Enfant-Jesus, Quebec City, Quebec, Canada (A.M., S.V.).
authors.forename: Demetrios J
authors.initials: DJ
authors.lastname: Sahlas
authors.affiliation: From the Department of Pathology and Laboratory Medicine (J.K.W.), Ottawa Hospital Health Research Institute (J.K.W., J.J.P., D.D., I.G.S.), Department of Emergency Medicine (J.J.P., I.G.S.), Department of Epidemiology and Community Medicine (G.A.W.), and Division of Neurology (D.D., G.S.), University of Ottawa, Ottawa, Ontario, Canada; Department of Emergency Medicine and of Pharmacology and Toxicology (M.L.A.S.), Department of Neurology (A.Y.J.), and Department of Emergency Medicine (H.M.), Queen's University, Kingston, Ontario, Canada; Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada (J.S.); Division of Emergency Medicine (A.W.), Division of Neurology (W.J.O., D.J.S.), and Population Health Research Institute (M.S.), Department of Neurology, McMaster University, Hamilton, Ontario, Canada; Department of Emergency Medicine, Université Laval, Quebec, Quebec, Canada (M.É.); and Department of Neurology, Hôpital de l'Enfant-Jesus, Quebec City, Quebec, Canada (A.M., S.V.).
authors.forename: Heather
authors.initials: H
authors.lastname: Murray
authors.affiliation: From the Department of Pathology and Laboratory Medicine (J.K.W.), Ottawa Hospital Health Research Institute (J.K.W., J.J.P., D.D., I.G.S.), Department of Emergency Medicine (J.J.P., I.G.S.), Department of Epidemiology and Community Medicine (G.A.W.), and Division of Neurology (D.D., G.S.), University of Ottawa, Ottawa, Ontario, Canada; Department of Emergency Medicine and of Pharmacology and Toxicology (M.L.A.S.), Department of Neurology (A.Y.J.), and Department of Emergency Medicine (H.M.), Queen's University, Kingston, Ontario, Canada; Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada (J.S.); Division of Emergency Medicine (A.W.), Division of Neurology (W.J.O., D.J.S.), and Population Health Research Institute (M.S.), Department of Neurology, McMaster University, Hamilton, Ontario, Canada; Department of Emergency Medicine, Université Laval, Quebec, Quebec, Canada (M.É.); and Department of Neurology, Hôpital de l'Enfant-Jesus, Quebec City, Quebec, Canada (A.M., S.V.).
authors.forename: Ariane
authors.initials: A
authors.lastname: MacKey
authors.affiliation: From the Department of Pathology and Laboratory Medicine (J.K.W.), Ottawa Hospital Health Research Institute (J.K.W., J.J.P., D.D., I.G.S.), Department of Emergency Medicine (J.J.P., I.G.S.), Department of Epidemiology and Community Medicine (G.A.W.), and Division of Neurology (D.D., G.S.), University of Ottawa, Ottawa, Ontario, Canada; Department of Emergency Medicine and of Pharmacology and Toxicology (M.L.A.S.), Department of Neurology (A.Y.J.), and Department of Emergency Medicine (H.M.), Queen's University, Kingston, Ontario, Canada; Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada (J.S.); Division of Emergency Medicine (A.W.), Division of Neurology (W.J.O., D.J.S.), and Population Health Research Institute (M.S.), Department of Neurology, McMaster University, Hamilton, Ontario, Canada; Department of Emergency Medicine, Université Laval, Quebec, Quebec, Canada (M.É.); and Department of Neurology, Hôpital de l'Enfant-Jesus, Quebec City, Quebec, Canada (A.M., S.V.).
authors.forename: Steve
authors.initials: S
authors.lastname: Verreault
authors.affiliation: From the Department of Pathology and Laboratory Medicine (J.K.W.), Ottawa Hospital Health Research Institute (J.K.W., J.J.P., D.D., I.G.S.), Department of Emergency Medicine (J.J.P., I.G.S.), Department of Epidemiology and Community Medicine (G.A.W.), and Division of Neurology (D.D., G.S.), University of Ottawa, Ottawa, Ontario, Canada; Department of Emergency Medicine and of Pharmacology and Toxicology (M.L.A.S.), Department of Neurology (A.Y.J.), and Department of Emergency Medicine (H.M.), Queen's University, Kingston, Ontario, Canada; Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada (J.S.); Division of Emergency Medicine (A.W.), Division of Neurology (W.J.O., D.J.S.), and Population Health Research Institute (M.S.), Department of Neurology, McMaster University, Hamilton, Ontario, Canada; Department of Emergency Medicine, Université Laval, Quebec, Quebec, Canada (M.É.); and Department of Neurology, Hôpital de l'Enfant-Jesus, Quebec City, Quebec, Canada (A.M., S.V.).
authors.forename: George A
authors.initials: GA
authors.lastname: Wells
authors.affiliation: From the Department of Pathology and Laboratory Medicine (J.K.W.), Ottawa Hospital Health Research Institute (J.K.W., J.J.P., D.D., I.G.S.), Department of Emergency Medicine (J.J.P., I.G.S.), Department of Epidemiology and Community Medicine (G.A.W.), and Division of Neurology (D.D., G.S.), University of Ottawa, Ottawa, Ontario, Canada; Department of Emergency Medicine and of Pharmacology and Toxicology (M.L.A.S.), Department of Neurology (A.Y.J.), and Department of Emergency Medicine (H.M.), Queen's University, Kingston, Ontario, Canada; Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada (J.S.); Division of Emergency Medicine (A.W.), Division of Neurology (W.J.O., D.J.S.), and Population Health Research Institute (M.S.), Department of Neurology, McMaster University, Hamilton, Ontario, Canada; Department of Emergency Medicine, Université Laval, Quebec, Quebec, Canada (M.É.); and Department of Neurology, Hôpital de l'Enfant-Jesus, Quebec City, Quebec, Canada (A.M., S.V.).
authors.forename: Dar
authors.initials: D
authors.lastname: Dowlatshahi
authors.affiliation: From the Department of Pathology and Laboratory Medicine (J.K.W.), Ottawa Hospital Health Research Institute (J.K.W., J.J.P., D.D., I.G.S.), Department of Emergency Medicine (J.J.P., I.G.S.), Department of Epidemiology and Community Medicine (G.A.W.), and Division of Neurology (D.D., G.S.), University of Ottawa, Ottawa, Ontario, Canada; Department of Emergency Medicine and of Pharmacology and Toxicology (M.L.A.S.), Department of Neurology (A.Y.J.), and Department of Emergency Medicine (H.M.), Queen's University, Kingston, Ontario, Canada; Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada (J.S.); Division of Emergency Medicine (A.W.), Division of Neurology (W.J.O., D.J.S.), and Population Health Research Institute (M.S.), Department of Neurology, McMaster University, Hamilton, Ontario, Canada; Department of Emergency Medicine, Université Laval, Quebec, Quebec, Canada (M.É.); and Department of Neurology, Hôpital de l'Enfant-Jesus, Quebec City, Quebec, Canada (A.M., S.V.).
authors.forename: Grant
authors.initials: G
authors.lastname: Stotts
authors.affiliation: From the Department of Pathology and Laboratory Medicine (J.K.W.), Ottawa Hospital Health Research Institute (J.K.W., J.J.P., D.D., I.G.S.), Department of Emergency Medicine (J.J.P., I.G.S.), Department of Epidemiology and Community Medicine (G.A.W.), and Division of Neurology (D.D., G.S.), University of Ottawa, Ottawa, Ontario, Canada; Department of Emergency Medicine and of Pharmacology and Toxicology (M.L.A.S.), Department of Neurology (A.Y.J.), and Department of Emergency Medicine (H.M.), Queen's University, Kingston, Ontario, Canada; Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada (J.S.); Division of Emergency Medicine (A.W.), Division of Neurology (W.J.O., D.J.S.), and Population Health Research Institute (M.S.), Department of Neurology, McMaster University, Hamilton, Ontario, Canada; Department of Emergency Medicine, Université Laval, Quebec, Quebec, Canada (M.É.); and Department of Neurology, Hôpital de l'Enfant-Jesus, Quebec City, Quebec, Canada (A.M., S.V.).
authors.forename: Ian G
authors.initials: IG
authors.lastname: Stiell
authors.affiliation: From the Department of Pathology and Laboratory Medicine (J.K.W.), Ottawa Hospital Health Research Institute (J.K.W., J.J.P., D.D., I.G.S.), Department of Emergency Medicine (J.J.P., I.G.S.), Department of Epidemiology and Community Medicine (G.A.W.), and Division of Neurology (D.D., G.S.), University of Ottawa, Ottawa, Ontario, Canada; Department of Emergency Medicine and of Pharmacology and Toxicology (M.L.A.S.), Department of Neurology (A.Y.J.), and Department of Emergency Medicine (H.M.), Queen's University, Kingston, Ontario, Canada; Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada (J.S.); Division of Emergency Medicine (A.W.), Division of Neurology (W.J.O., D.J.S.), and Population Health Research Institute (M.S.), Department of Neurology, McMaster University, Hamilton, Ontario, Canada; Department of Emergency Medicine, Université Laval, Quebec, Quebec, Canada (M.É.); and Department of Neurology, Hôpital de l'Enfant-Jesus, Quebec City, Quebec, Canada (A.M., S.V.).
authors.forename: Mukul
authors.initials: M
authors.lastname: Sharma
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000000981:diagnostic imaging*; D002545:Brain Ischemia / Q000150:complications / Q000000981:diagnostic imaging*; D059345:Cerebral Small Vessel Diseases / Q000150:complications / Q000000981:diagnostic imaging*; D002908:Chronic Disease; D005260:Female; D006801:Humans; D002546:Ischemic Attack, Transient / Q000000981:diagnostic imaging* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D018570:Risk Assessment / Q000379:methods*; D013223:Statistics as Topic; D020521:Stroke / Q000000981:diagnostic imaging* / Q000209:etiology; D014057:Tomography, X-Ray Computed
keywords: brain infarction; stroke; tomography scanners, x-ray, computed; transient ischemic attack