Early infarct growth predicts long-term clinical outcome after thrombolysis.
BACKGROUND
Ischemic lesion growth may be a surrogate marker of clinical outcome, but no such interrelationship after thrombolysis has yet been determined. We evaluated the association between early infarct growth on diffusion-weighted imaging (DWI) and long-term clinical outcome after thrombolysis.


METHODS
We retrospectively reviewed outcomes in patients with acute middle cerebral artery territory stroke who had been treated with intravenous tissue plasminogen activator or intra-arterial urokinase. DWI lesion volumes were measured at baseline and within 7 days, and the difference was calculated. Clinical outcome was evaluated using the modified Rankin Scale (mRS) at 3 months. Good and poor clinical outcomes were defined as: a) mRS 0-1 vs. mRS 2-6, b) mRS 0-2 vs. mRS 3-6, and c) responder analysis which was influenced by the baseline National Institutes of Health Stroke Scale (NIHSS) scores: good and poor outcomes were defined as mRS 0 vs. mRS 1-6 if the baseline NIHSS score was <8, mRS 0-1 vs. mRS 2-6 if the NIHSS score was 8-14, and mRS 0-2 vs. mRS 3-6 if the NIHSS score was >14. The relationship between the ischemic lesion volume change and clinical outcome was explored. The cut-off value of infarct growth predicting long-term outcome was estimated using receiver operating characteristic analysis.


RESULTS
Of the 81 patients included, 67 (82.7%) showed lesion growth, and absolute growth was significantly related to poor outcomes (P<0.001 all for mRS 2-6, mRS 3-6, and responder analysis). Multivariate analysis showed that absolute lesion growth was an independent predictor of poor outcome, defined as mRS 2-6 (P=0.002; odds ratio [OR], 1.06; 95% confidence interval [CI], 1.02-1.10), mRS 3-6 (P=0.001; OR, 1.06; 95% CI, 1.02-1.10), and poor outcome by responder analysis (P=0.001; OR, 1.06; 95% CI, 1.03-1.10). The cut-off values of lesion growth that discriminated between good and poor outcomes were 14.11 cm(3) for mRS 2-6; 15.87 cm(3) for mRS 3-6; and 14.11 cm(3) in responder analysis.


CONCLUSIONS
Early DWI lesion growth is an independent predictor of poor outcome after thrombolysis and may serve a potential surrogate marker of clinical outcome in acute stroke trials.
Stroke Center, Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, Republic of Korea.
Kyung-Hee
KH
Cho
Sun U
SU
Kwon
Deok Hee
DH
Lee
WooHyun
W
Shim
ChoongGon
C
Choi
Sang Joon
SJ
Kim
Dae-Chul
DC
Suh
Jong S
JS
Kim
Dong-Wha
DW
Kang
D000368:Aged; D002544:Cerebral Infarction / Q000188:drug therapy* / Q000209:etiology / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D020244:Infarction, Middle Cerebral Artery / Q000150:complications / Q000188:drug therapy* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D015912:Thrombolytic Therapy / Q000379:methods*; D013997:Time Factors; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use*; D016896:Treatment Outcome
D010959:Tissue Plasminogen Activator