title: Addition of brain infarction to the ABCD2 Score (ABCD2I): a collaborative analysis of unpublished data on 4574 patients.
abstract: OBJECTIVE
  The ABCD system was developed to predict early stroke risk after transient ischemic attack. Incorporation of brain imaging findings has been suggested, but reports have used inconsistent methods and been underpowered. We therefore performed an international, multicenter collaborative study of the prognostic performance of the ABCD(2) score and brain infarction on imaging to determine the optimal weighting of infarction in the score (ABCD(2)I).
  
  
  METHODS
  Twelve centers provided unpublished data on ABCD(2) scores, presence of brain infarction on either diffusion-weighted imaging or CT, and follow-up in cohorts of patients with transient ischemic attack diagnosed by World Health Organization criteria. Optimal weighting of infarction in the ABCD(2)I score was determined using area under the receiver operating characteristic curve analyses and random effects meta-analysis.
  
  
  RESULTS
  Among 4574 patients with TIA, acute infarction was present in 884 (27.6%) of 3206 imaged with diffusion-weighted imaging and new or old infarction was present in 327 (23.9%) of 1368 imaged with CT. ABCD(2) score and presence of infarction on diffusion-weighted imaging or CT were both independently predictive of stroke (n=145) at 7 days (after adjustment for ABCD(2) score, OR for infarction=6.2, 95% CI=4.2 to 9.0, overall; 14.9, 7.4 to 30.2, for diffusion-weighted imaging; 4.2, 2.6 to 6.9, for CT; all P<0.001). Incorporation of infarction in the ABCD(2)I score improved predictive power with an optimal weighting of 3 points for infarction on CT or diffusion-weighted imaging. Pooled areas under the curve increased from 0.66 (0.53 to 0.78) for the ABCD(2) score to 0.78 (0.72 to 0.85) for the ABCD(2)I score.
  
  
  CONCLUSIONS
  In secondary care, incorporation of brain infarction into the ABCD system (ABCD(2)I score) improves prediction of stroke in the acute phase after transient ischemic attack.
authors.affiliation: Stroke Prevention Research Unit (M.F.G., P.M.R.), National Institute for Health Research Biomedical Research Centre, Oxford, UK. matthew.giles@clneuro.ox.ac.uk
authors.forename: Matthew F
authors.initials: MF
authors.lastname: Giles
authors.forename: Greg W
authors.initials: GW
authors.lastname: Albers
authors.forename: Pierre
authors.initials: P
authors.lastname: Amarenco
authors.forename: Murat M
authors.initials: MM
authors.lastname: Arsava
authors.forename: Andrew
authors.initials: A
authors.lastname: Asimos
authors.forename: Hakan
authors.initials: H
authors.lastname: Ay
authors.forename: David
authors.initials: D
authors.lastname: Calvet
authors.forename: Shelagh
authors.initials: S
authors.lastname: Coutts
authors.forename: Brett L
authors.initials: BL
authors.lastname: Cucchiara
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Demchuk
authors.forename: S Claiborne
authors.initials: SC
authors.lastname: Johnston
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Kelly
authors.forename: Anthony S
authors.initials: AS
authors.lastname: Kim
authors.forename: Julien
authors.initials: J
authors.lastname: Labreuche
authors.forename: Philippa C
authors.initials: PC
authors.lastname: Lavallee
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Mas
authors.forename: Aine
authors.initials: A
authors.lastname: Merwick
authors.forename: Jean Marc
authors.initials: JM
authors.lastname: Olivot
authors.forename: Francisco
authors.initials: F
authors.lastname: Purroy
authors.forename: Wayne D
authors.initials: WD
authors.lastname: Rosamond
authors.forename: Rossella
authors.initials: R
authors.lastname: Sciolla
authors.forename: Peter M
authors.initials: PM
authors.lastname: Rothwell
mesh_terms: D020520:Brain Infarction / Q000175:diagnosis*; D005260:Female; D006801:Humans; D002546:Ischemic Attack, Transient / Q000175:diagnosis*; D008297:Male; D011379:Prognosis; D012306:Risk; D018570:Risk Assessment; D012307:Risk Factors; D020521:Stroke / Q000175:diagnosis*