title: D-dimer, magnetic resonance imaging diffusion-weighted imaging, and ABCD2 score for transient ischemic attack risk stratification.
abstract: BACKGROUND
  We sought to determine whether measurement of D-dimer (DD) would improve risk stratification after transient ischemic attack (TIA).
  
  
  METHODS
  We enrolled 167 patients with acute TIA in a prospective observational study. DD was measured using rapid enzyme-linked immunosorbent assay. The primary outcome measure was a composite end point consisting of stroke or death within 90 days or the identification of a high-risk stroke mechanism requiring specific early intervention (defined as > or =50% stenosis in a vessel referable to symptoms or a cardioembolic source warranting anticoagulation).
  
  
  RESULTS
  The composite end point occurred in 41 patients (25%). A 50% or greater stenosis was found in 25 patients (15%), a cardioembolic source in 14 (8%), and clinical events in 8 (5 strokes, 3 deaths), 6 of whom also had a high-risk cause of TIA. ABCD(2) score was associated with outcome (P for trend = .017, c-statistic 0.63). DD levels did not differ based on outcome status (geometric mean 0.75 v 0.82 microg fibrinogen equivalent unit/mL, P = .56), and DD had little use for predicting outcome (c-statistic 0.57), even when combined with ABCD(2) score. Of 96 patients with early magnetic resonance imaging (MRI), 23% had diffusion-weighted imaging (DWI) abnormalities, and MRI DWI was predictive of outcome (c-statistic 0.76). The addition of MRI DWI to ABCD(2) improved predictive accuracy (c-statistic 0.83) compared with either alone.
  
  
  CONCLUSIONS
  Many patients with TIA have a high-risk mechanism (large vessel stenosis or cardioembolism) or will experience stroke/death within 90 days. Increasing ABCD(2) scores were associated with this composite end point. Measurement of DD did not provide additional prognostic information.
authors.affiliation: University of Pennsylvania, Philadelphia 19104, USA. cucchiar@mail.med.upenn.edu
authors.forename: Brett L
authors.initials: BL
authors.lastname: Cucchiara
authors.forename: Steve R
authors.initials: SR
authors.lastname: Messe
authors.forename: Lauren
authors.initials: L
authors.lastname: Sansing
authors.forename: Larami
authors.initials: L
authors.lastname: MacKenzie
authors.forename: Robert A
authors.initials: RA
authors.lastname: Taylor
authors.forename: James
authors.initials: J
authors.lastname: Pacelli
authors.forename: Qaisar
authors.initials: Q
authors.lastname: Shah
authors.forename: Eleanor S
authors.initials: ES
authors.lastname: Pollak
authors.forename: Scott E
authors.initials: SE
authors.lastname: Kasner
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000032:analysis / Q000097:blood; D016893:Carotid Stenosis / Q000175:diagnosis* / Q000453:epidemiology* / Q000503:physiopathology; D015897:Comorbidity; D038524:Diffusion Magnetic Resonance Imaging; D018450:Disease Progression; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis / Q000378:metabolism*; D006801:Humans; D002546:Ischemic Attack, Transient / Q000175:diagnosis* / Q000453:epidemiology* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D011237:Predictive Value of Tests; D011446:Prospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D020521:Stroke / Q000453:epidemiology*
chemical_list: D015415:Biomarkers; D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D