title: Carotid plaque inflammation on 18F-fluorodeoxyglucose positron emission tomography predicts early stroke recurrence.
abstract: OBJECTIVE
  Symptomatic carotid stenosis is associated with a 3-fold risk of early stroke recurrence compared to other stroke subtypes. Current carotid imaging techniques rely on estimating plaque-related lumen narrowing but do not evaluate intraplaque inflammation, a key mediator of plaque rupture and thromboembolism. Using combined (18) F-fluorodeoxyglucose positron-emission tomography (FDG-PET)/computed tomography, we investigated the relation between inflammation-related FDG uptake and stroke recurrence.
  
  
  METHODS
  Consecutive patients with a recent (median, 6.5 days; interquartile range, 4-8) stroke, transient ischemic attack (TIA), or retinal embolism and ipsilateral carotid stenosis (≥50%) were included. FDG uptake was quantified as mean standardized uptake values (SUVs, g/ml). Patients were followed prospectively for stroke recurrence.
  
  
  RESULTS
  Sixty patients were included (25 stroke, 29 TIA, 6 retinal embolism). Twenty-two percent (13 of 60) had stroke recurrence within 90 days. FDG uptake in ipsilateral carotid plaque was greater in patients with early recurrent stroke (mean SUV, 1.85 g/ml; standard deviation [SD], 0.44 vs 1.58 g/ml; SD, 0.32, p = 0.02). On life-table analysis, 90-day recurrence rates with mean SUV greater than a 2.14 g/ml threshold were 80% (95% confidence interval [CI], 41.8-99.2) versus 22.9% (95% CI, 12.3-40.3) with SUV ≤2.14 g/ml (log-rank, p < 0.0001). In a Cox regression model including age and degree of stenosis (50-69% or ≥70%), mean plaque FDG uptake was the only independent predictor of stroke recurrence (adjusted hazard ratio, 6.1; 95% CI, 1.3-28.8; p = 0.02).
  
  
  CONCLUSIONS
  In recently symptomatic carotid stenosis, inflammation-related FDG uptake was associated with early stroke recurrence, independent of the degree of stenosis. Plaque FDG-PET may identify patients at highest risk for stroke recurrence, who may be selected for immediate revascularization or intensive medical treatment.
authors.affiliation: Neurovascular Clinical Science Unit, Mater University Hospital/University College Dublin at Dublin Academic Medical Centre, Ireland. mmarnane@gmail.com
authors.forename: Michael
authors.initials: M
authors.lastname: Marnane
authors.forename: Aine
authors.initials: A
authors.lastname: Merwick
authors.forename: Orla C
authors.initials: OC
authors.lastname: Sheehan
authors.forename: Niamh
authors.initials: N
authors.lastname: Hannon
authors.forename: Paul
authors.initials: P
authors.lastname: Foran
authors.forename: Tim
authors.initials: T
authors.lastname: Grant
authors.forename: Eamon
authors.initials: E
authors.lastname: Dolan
authors.forename: Joan
authors.initials: J
authors.lastname: Moroney
authors.forename: Sean
authors.initials: S
authors.lastname: Murphy
authors.forename: Killian
authors.initials: K
authors.lastname: O'Rourke
authors.forename: Kevin
authors.initials: K
authors.lastname: O'Malley
authors.forename: Martin
authors.initials: M
authors.lastname: O'Donohoe
authors.forename: Ciaran
authors.initials: C
authors.lastname: McDonnell
authors.forename: Imelda
authors.initials: I
authors.lastname: Noone
authors.forename: Mary
authors.initials: M
authors.lastname: Barry
authors.forename: Morgan
authors.initials: M
authors.lastname: Crowe
authors.forename: Eoin
authors.initials: E
authors.lastname: Kavanagh
authors.forename: Martin
authors.initials: M
authors.lastname: O'Connell
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Kelly
mesh_terms: D000368:Aged; D016893:Carotid Stenosis / Q000150:complications / Q000000981:diagnostic imaging*; D042241:Early Diagnosis; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007249:Inflammation / Q000150:complications / Q000000981:diagnostic imaging*; D008297:Male; D064847:Multimodal Imaging; D058226:Plaque, Atherosclerotic / Q000150:complications / Q000000981:diagnostic imaging*; D049268:Positron-Emission Tomography; D016016:Proportional Hazards Models; D012372:ROC Curve; D019275:Radiopharmaceuticals; D012008:Recurrence; D012680:Sensitivity and Specificity; D020521:Stroke / Q000000981:diagnostic imaging* / Q000209:etiology; D014057:Tomography, X-Ray Computed
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18