Bleeding risk analysis in stroke imaging before thromboLysis (BRASIL): pooled analysis of T2*-weighted magnetic resonance imaging data from 570 patients.
OBJECTIVE
There has been speculation that the risk of secondary symptomatic intracranial hemorrhage (SICH) may be increased after thrombolytic therapy in ischemic stroke patients who have cerebral microbleeds (CMBs) on T2*-weighted magnetic resonance imaging. Because of this concern, some centers withhold potentially beneficial thrombolytic therapy from these patients.


METHODS
We analyzed magnetic resonance imaging data acquired within 6 hours after symptom onset from 570 ischemic stroke patients treated with intravenous tissue plasminogen activator in 13 centers in Europe, North America, and Asia. Baseline T2*-weighted magnetic resonance images were evaluated for the presence of CMBs. The primary end point was SICH, defined as clinical deterioration with an increase in the National Institutes of Health Stroke Scale score by >or=4 points, temporally related to a parenchymal hematoma on follow-up-imaging.


RESULTS
A total of 242 CMBs were detected in 86 of 570 patients (15.1%). The number of CMBs ranged from 1 to 77 in the individual patient, with >or=5 CMBs in 6 of 570 patients (1.1%). Proportions of patients with SICH were 5.8% (95% CI, 1.9 to 13.0) in the presence of CMBs and 2.7% (95% CI, 1.4 to 4.5) in patients without CMBs (P=0.170, Fisher's exact test), resulting in no significant absolute increase in the risk of SICH of 3.1% (95% CI, -2.0 to 8.3).


CONCLUSIONS
The data suggest that if there is any increased risk of SICH attributable to CMBs, it is likely to be small and unlikely to exceed the benefits of thrombolytic therapy. No reliable conclusion regarding risk in the rare patient with multiple CMBs can be reached.
Fiehler
Jens
J
Department of Neuroradiology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany. fiehler@uke.uni-hamburg.de
Albers
Gregory W
GW
Boulanger
Jean-Martin
JM
Derex
Laurent
L
Gass
Achim
A
Hjort
Niels
N
Kim
Jong S
JS
Liebeskind
David S
DS
Neumann-Haefelin
Tobias
T
Pedraza
Salvador
S
Rother
Joachim
J
Rothwell
Peter
P
Rovira
Alex
A
Schellinger
Peter D
PD
Trenkler
Johannes
J
D000368:Aged; D002545:Brain Ischemia / Q000188:drug therapy / Q000453:epidemiology / Q000473:pathology; D002543:Cerebral Hemorrhage / Q000453:epidemiology* / Q000473:pathology* / Q000517:prevention & control; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D012307:Risk Factors; D020521:Stroke / Q000188:drug therapy / Q000453:epidemiology* / Q000473:pathology*; D015912:Thrombolytic Therapy / Q000009:adverse effects*