Compromised cerebral blood flow reactivity is a predictor of stroke in patients with symptomatic carotid artery occlusive disease.
OBJECTIVE
The purpose of this study was to determine whether the hemodynamic consequences of extracranial carotid disease correlate with the risk of subsequent cerebral infarction.


METHODS
In 95 patients with symptoms who had greater than or equal to 70% stenosis (31 patients) or who had occlusion (64 patients) of the ipsilateral carotid artery, cerebral blood flow was measured by the stable xenon/computed tomography technique both at baseline and after vasodilatory challenge with intravenous acetazolamide. Patients were stratified into group 1, 43 patients with no more than a 5% decrease in flow in any vascular territory, and group 2, 52 patients with greater than a 5% decrease in one or more vascular territories after an acetazolamide challenge.


RESULTS
In group 2, 15 (28.9%) of 52 patients had a new stroke, but only one (2.3%) of 43 patients in group 1 did (p = 0.0005). Of patients with total carotid occlusion 10 (26%) of 38 in group 2 and none (0%) of 26 in group 1 had a new stroke (p = 0.003). Of patients with greater than or equal to 70% stenosis, five (36%) of 14 in group 2 and only one (6%) of 17 in group 1 had a stroke (p = 0.067).


CONCLUSIONS
The loss of cerebral reactivity in patients with symptoms who had greater than or equal to 70% carotid stenosis or occlusion is an important predictor of impending cerebral infarction.
Department of Surgery, University of Pittsburgh School of Medicine, PA.
M W
MW
Webster
M S
MS
Makaroun
D L
DL
Steed
H A
HA
Smith
D W
DW
Johnson
H
H
Yonas
D000086:Acetazolamide / Q000494:pharmacology; D000328:Adult; D000368:Aged; D016893:Carotid Stenosis / Q000150:complications* / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002536:Cerebral Arteries / Q000187:drug effects / Q000503:physiopathology; D002544:Cerebral Infarction / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology; D002560:Cerebrovascular Circulation / Q000187:drug effects / Q000502:physiology*; D002561:Cerebrovascular Disorders / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D005544:Forecasting; D006801:Humans; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D012189:Retrospective Studies; D012307:Risk Factors; D014057:Tomography, X-Ray Computed / Q000379:methods; D014665:Vasodilator Agents / Q000494:pharmacology; D014978:Xenon
D014665:Vasodilator Agents; D014978:Xenon; D000086:Acetazolamide