title: Benign prognosis of never-symptomatic carotid occlusion.
abstract: OBJECTIVE
  To determine the prognosis of asymptomatic carotid artery occlusion.
  
  
  BACKGROUND
  As opposed to symptomatic carotid occlusion, little information is available on the prognosis of asymptomatic carotid occlusion.
  
  
  METHODS
  Thirty never-symptomatic and 81 symptomatic patients with carotid occlusion underwent baseline assessment of 15 risk factors together with PET measurements of oxygen extraction fraction (OEF). Every 6-month telephone contact recorded interval medical treatment and subsequent stroke occurrence during an average follow-up of 32 months. Patients, treating physicians, and an end point adjudicator were blinded to PET results.
  
  
  RESULTS
  Ischemic stroke occurred in 1 of 30 of never-symptomatic patients (3.3%) and 15 of 81 of symptomatic patients (18.5%; p = 0.03). No strokes in the carotid territory distal to the occluded vessel occurred in the never-symptomatic patients. Multivariate analysis of baseline risk factors for all 111 patients revealed that age, plasma fibrinogen level, and PET findings of high OEF distal to the occluded carotid artery were the only independent predictors of subsequent stroke (p < 0.05). Previous ipsilateral hemispheric or retinal symptoms was not a significant predictive variable. The lower risk of stroke in never-symptomatic patients was associated with a lower incidence of high OEF (4 of 30) as opposed to symptomatic patients (39 of 81; p = 0.002), but there was no significant difference in age or fibrinogen level.
  
  
  CONCLUSIONS
  Never-symptomatic carotid occlusion carries a very low risk of subsequent ischemic stroke. This benign prognosis is associated with a low incidence of cerebral hemodynamic compromise in these patients. These data support further the importance of hemodynamic factors in the pathogenesis of ischemic stroke in patients with carotid occlusion.
authors.affiliation: Department of Neurology and Neurological Surgery, Edward Mallinckrodt Institute of Radiology, St. Louis, MO, USA.
authors.forename: W J
authors.initials: WJ
authors.lastname: Powers
authors.forename: C P
authors.initials: CP
authors.lastname: Derdeyn
authors.forename: S M
authors.initials: SM
authors.lastname: Fritsch
authors.forename: D A
authors.initials: DA
authors.lastname: Carpenter
authors.forename: K D
authors.initials: KD
authors.lastname: Yundt
authors.forename: T O
authors.initials: TO
authors.lastname: Videen
authors.forename: R L
authors.initials: RL
authors.lastname: Grubb
mesh_terms: D000368:Aged; D001157:Arterial Occlusive Diseases / Q000503:physiopathology*; D002340:Carotid Artery Diseases / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis