title: Interaction of incidental microbleeds and prior use of antithrombotics with early hemorrhagic transformation: Causative or protective?
abstract: BACKGROUND
  Gradient echo (GRE) sequence of magnetic resonance imaging (MRI) is a sensitive tool to detect hemorrhagic transformation (HT) and old cerebral microbleeds (CMBs). Presence of CMBs and prior use of antithrombotics pose a risk of HT in ischemic stroke. We evaluated the association of CMBs and antithrombotic use with resultant HT in acute ischemic stroke (AIS).
  
  
  METHODS
  This retrospective study included AIS patients admitted to our center between January 2009 and August 2010 who underwent GRE-weighted MRI within 48 h of admission. Demographic and clinical data including diabetes mellitus, hypertension, hyperlipidemia, prior intake of antiplatelets/anticoagulants/statins, and presence of CMBs at admission were collected and compared between patients who developed HT and those who did not. We did a multivariate analysis using logistic regression to assess the effect of CMBs and prior use of antithrombotic agents on the risk of development for early HT in ischemic stroke.
  
  
  RESULTS
  Of 529 AIS patients, 81 (15%) were found to have HT during the initial hospital course. CMBs were found in only 9 of 81 patients (11%) with HT and in 40 out of remaining 448 patients (9%) who did not develop HT. The presence of CMBs was not associated with increased risk of HT (P= 0.53). However, prior use of antiplatelets (33% vs. 47% in the patients without HT,P= 0.02) was associated with decreased risk of HT in ischemic stroke.
  
  
  CONCLUSIONS
  Presence of incidental CMBs was not associated with increased risk for early HT of an ischemic stroke. Interestingly, the prior intake of antiplatelets was found to be protective against HT of ischemic stroke.
authors.affiliation: Department of Neurology, University of California Los Angeles, Los Angeles, CA, USA.
authors.forename: Konark
authors.initials: K
authors.lastname: Malhotra
authors.affiliation: Cleveland Clinic Foundation, Cleveland, OH, USA.
authors.forename: Monica
authors.initials: M
authors.lastname: Khunger
authors.affiliation: Department of Neurology, RUSH University Medical Center, Chicago, IL, USA.
authors.forename: Bichun
authors.initials: B
authors.lastname: Ouyang
authors.affiliation: Department of Neurology, University of California Los Angeles, Los Angeles, CA, USA.
authors.forename: David S
authors.initials: DS
authors.lastname: Liebeskind
authors.affiliation: Department of Internal Medicine, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Yousef M
authors.initials: YM
authors.lastname: Mohammad
keywords: Acute ischemic stroke; cerebral microbleeds; gradient echo magnetic resonance imaging; hemorrhagic transformation