Silent infarction as a risk factor for overt stroke in children with sickle cell anemia: a report from the Cooperative Study of Sickle Cell Disease.
OBJECTIVE
To determine whether children with homozygous sickle cell anemia (SCD) who have silent infarcts on magnetic resonance imaging (MRI) of the brain are at increased risk for overt stroke.


METHODS
We selected patients with homozygous SCD who (1) enrolled in the Cooperative Study of Sickle Cell Disease (CSSCD) before age 6 months, (2) had at least 1 study-mandated brain MRI at age 6 years or older, and (3) had no overt stroke before a first MRI. MRI results and clinical and laboratory parameters were tested as predictors of stroke.


RESULTS
Among 248 eligible patients, mean age at first MRI was 8.3 +/- 1.9 years, and mean follow-up after baseline MRI was 5.2 +/- 2.2 years. Five (8.1%) of 62 patients with silent infarct had strokes compared with 1 (0.5%) of 186 patients without prior silent infarct; incidence per 100 patient-years of follow-up was increased 14-fold (1.45 per 100 patient-years vs 0.11 per 100 patient-years, P =.006). Of several clinical and laboratory parameters examined, silent infarct was the strongest independent predictor of stroke (hazard ratio = 7.2, P =.027).


CONCLUSIONS
Silent infarct identified at age 6 years or older is associated with increased stroke risk.
Miller
S T
ST
State University of New York-Downstate Medical Center/Kings County Hospital, Brooklyn, New York 11203, USA.
Macklin
E A
EA
Pegelow
C H
CH
Kinney
T R
TR
Sleeper
L A
LA
Bello
J A
JA
DeWitt
L D
LD
Gallagher
D M
DM
Guarini
L
L
Moser
F G
FG
Ohene-Frempong
K
K
Sanchez
N
N
Vichinsky
E P
EP
Wang
W C
WC
Wethers
D L
DL
Younkin
D P
DP
Zimmerman
R A
RA
DeBaun
M R
MR
D000755:Anemia, Sickle Cell / Q000150:complications*; D002648:Child; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D009203:Myocardial Infarction / Q000150:complications* / Q000175:diagnosis; D012307:Risk Factors; D020521:Stroke / Q000209:etiology*