Benign prognosis of never-symptomatic carotid occlusion

Objective: To determine the prognosis of asymptomatic carotid artery occlus ion. Background: As opposed to symptomatic carotid occlusion, little inform ation is available on the prognosis of asymptomatic carotid occlusion. Meth od: Thirty never-symptomatic and 81 symptomatic patients with carotid occlu sion underwent baseline assessment of 15 risk factors together with PET mea surements of oxygen extraction fraction. (OEF). Every B-month telephone con tact recorded interval medical treatment and subsequent stroke occurrence d uring an average follow-up of 32 months. Patients, treating physicians, and an end point adjudicator were blinded to PET results. Results: Ischemic st roke 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 territ ory distal to the occluded vessel occurred in the never-symptomatic patient s. Multivariate analysis of baseline risk factors for all 111 patients reve aled that age, plasma fibrinogen level, and PET findings of high OEF distal to the occluded carotid artery were the only independent predictors of sub sequent stroke (p < 0.05). Previous ipsilateral hemispheric or retinal symp toms was not a significant predictive variable. The lower risk of stroke in never-symptomatic patients was associated with a lower incidence of high O EF (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 fu rther the importance of hemodynamic factors in the pathogenesis of ischemic stroke in patients with carotid occlusion.