Recurrent ischemia in symptomatic carotid occlusion - Prognostic value of hemodynamic factors

Objective: To identify hemodynamic factors that predict recurrence of ipsil ateral cerebral ischemic events in patients with symptomatic carotid artery occlusion (CAO). Patients and Methods: The authors studied 117 consecutive patients with CAO and corresponding recent (less than or equal to6 months) ischemic symptoms of the brain or eye that were transient or at most mildl y disabling. They determined, using Cox proportional hazards analysis, the prognostic value for recurrence of ipsilateral cerebral ischemic events of 1) clinical features believed to indicate hemodynamic compromise, 2) collat eral blood flow pattern, and 3) transcranial Doppler CO2-reactivity. Result s: None of the 24 patients with symptoms of retinal ischemia alone had a re current cerebral ischemic event. In the 93 patients with cerebral ischemic symptoms on entry, recurrence of these symptoms was independently predicted by 1) the nature of the initial symptoms being of purported hemodynamic or igin (limb-shaking, precipitation of symptoms by rising, exercise or low bl ood pressure, retinal claudication) (hazard ratio [HR] 3.8, 95% CI 1.5 to 9 .5), 2) continuing symptoms after the CAO had been documented, but before i nclusion in the study (HR 5.9, 95% CI 2.2 to 16.1), and 3) the presence of collateral blood flow via leptomeningeal vessels (HR 4.1, 95% CI 1.3 to 13. 1). CO2-reactivity did not predict recurrence of cerebral ischemic events. Conclusions: Having cerebral in contrast to retinal ischemia, clinical feat ures suggestive of hemodynamic compromise, continuing symptoms after demons tration of the CAO, and presence of leptomeningeal collaterals may help to identify patients with symptomatic CAO at high risk of future cerebral isch emia.