title: Elevated blood flow velocity in the anterior cerebral artery and stroke risk in sickle cell disease: extended analysis from the STOP trial.
abstract: Elevated velocity in the internal carotid artery (ICA) or middle cerebral artery (MCA), detected by transcranial Doppler (TCD) ultrasonography, predicts an increased risk of stroke in children with sickle cell disease (SCD). Although strokes also occur in an anterior cerebral artery (ACA) distribution, the significance of elevated velocity in this vessel has not been determined previously. We assessed the effect of elevated ACA velocity on stroke risk using the results of the first adequate TCD study performed on 1975 children as part of The Stroke Prevention Trial in Sickle Cell Anemia (STOP). Elevated ACA velocity (> or =170 cm/s) was associated with an increased risk of stroke (P = 0.0013) after adjusting for the ICA/MCA classification. Among subjects with normal ICA/MCA velocity, the risk of stroke was more than 10-fold greater in those with elevated compared with normal ACA velocity (2.13 and 0.20 per 100 patient-years, respectively, P < 0.001); risk more than doubled with elevated compared with normal ACA velocity in those already at high risk due to abnormal ICA/MCA findings (7.56 vs. 3.22 per 100 patient-years, P = 0.042). Few of the strokes in those with elevated ACA velocity occurred in an ACA distribution, suggesting changes in blood flow velocity in anterior vessels may be associated with diffuse arterial disease or, alternatively, manifest collateral flow from compromised middle cerebral vessels.
authors.affiliation: Division of Hematology, The Children's Hospital of Philadelphia and Department of Pediatrics, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA. kwiatkowski@email.chop.edu
authors.forename: Janet L
authors.initials: JL
authors.lastname: Kwiatkowski
authors.forename: Suzanne
authors.initials: S
authors.lastname: Granger
authors.forename: Donald J
authors.initials: DJ
authors.lastname: Brambilla
authors.forename: R Clark
authors.initials: RC
authors.lastname: Brown
authors.forename: Scott T
authors.initials: ST
authors.lastname: Miller
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Adams
mesh_terms: D000293:Adolescent; D000755:Anemia, Sickle Cell / Q000150:complications* / Q000000981:diagnostic imaging / Q000628:therapy*; D020771:Anterior Cerebral Artery / Q000000981:diagnostic imaging* / Q000473:pathology; D001783:Blood Flow Velocity; D001803:Blood Transfusion; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D016014:Linear Models; D008279:Magnetic Resonance Imaging; D008297:Male; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging / Q000473:pathology; D018570:Risk Assessment; D020521:Stroke / Q000175:diagnosis / Q000209:etiology* / Q000517:prevention & control; D017585:Ultrasonography, Doppler, Transcranial