Brain microbleeds as a potential risk factor for antiplatelet-related intracerebral haemorrhage: hospital-based, case-control study.
BACKGROUND
Intracerebral haemorrhage (ICH) is an uncommon but devastating complication of regular antiplatelet use: identifying high-risk patients before treatment could potentially reduce this hazard. Brain microbleeds on gradient-recalled echo (GRE) T2*-weighted MRI are considered a biomarker for bleeding-prone small-vessel diseases. The authors hypothesised that microbleeds are a risk factor for antiplatelet-related ICH, and investigated this in a hospital-based matched case-control study.


METHODS
Cases of spontaneous ICH were ascertained, using overlapping methods, from a prospective database of 1017 consecutive unselected patients referred to our stroke unit and associated clinics. For each case of antiplatelet-related ICH, two controls matched for age, sex and hypertension without history of ICH on antiplatelet therapy were selected. Microbleeds were identified by a trained observer blinded to clinical details.


RESULTS
Microbleeds were more frequent in antiplatelet users with ICH than in matched antiplatelet users without ICH (13/16 (81%) vs 6/32 (19%), p=0.004) and patients with non-antiplatelet-related ICH (13/16 (81%) vs 15/33 (45%), p=0.03). The frequency of lobar microbleeds was 11/16 (69%) in antiplatelet-related ICH versus 11/33 (33%) in non antiplatelet-related ICH (p=0.032). Microbleeds were more numerous in antiplatelet users with ICH compared with controls (p=0.016). The number of microbleeds was associated with the risk of antiplatelet-related ICH (adjusted OR 1.33 per additional microbleed, 95% CI 1.06 to 1.66, p=0.013).


CONCLUSIONS
Brain microbleeds are associated with antiplatelet-related ICH. In patients with a large number of lobar microbleeds, the risk of ICH could outweigh the benefits of antiplatelet therapy. Larger prospective studies to investigate the prognostic significance of microbleeds in regular antiplatelet users are warranted.
Stroke Research Group, Department of Brain Repair and Rehabilitation, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK.
S M
SM
Gregoire
H R
HR
Jäger
T A
TA
Yousry
C
C
Kallis
M M
MM
Brown
D J
DJ
Werring
D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002543:Cerebral Hemorrhage / Q000139:chemically induced* / Q000453:epidemiology / Q000473:pathology; D005260:Female; D006761:Hospitals / Q000706:statistics & numerical data*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010975:Platelet Aggregation Inhibitors / Q000009:adverse effects*; D012307:Risk Factors
D010975:Platelet Aggregation Inhibitors