title: Analysis of Hemorrhage Volumes After Angiogram-Negative Subarachnoid Hemorrhage.
abstract: BACKGROUND
  Antiplatelet medication use is associated with worsened outcome after angiogram-negative subarachnoid hemorrhage (SAH). It has been hypothesized that these worsened outcomes may be the result of an association between antiplatelet medication use and increased hemorrhage volumes after angiogram-negative SAH. To test this hypothesis, we performed volumetric analysis of computed tomography (CT)-defined hemorrhage after angiogram-negative SAH.
  
  
  METHODS
  This was a retrospective analysis of patients presenting with nontraumatic, angiogram-negative SAH in the Columbia University Subarachnoid Hemorrhage Outcomes database between 2000 and 2013. SAH volumes on admission head CT scans were measured using the MIPAV software package, version 7.20 in a semiautomated fashion.
  
  
  RESULTS
  A total of 108 presenting CT scans from patients with angiogram-negative SAH were analyzed. The mean hemorrhage volume was 14.3 mL in the patients with a history of antiplatelet medication use, compared with 6.8 mL in those with no history of antiplatelet use. This difference was found to be significant (P = 0.0029).
  
  
  CONCLUSIONS
  Antiplatelet medication use is associated with increased SAH volumes in patients with angiogram-negative SAH. Increased hemorrhage volumes may contribute to poor outcomes in this patient population. Prospective studies are warranted to confirm this association.
authors.affiliation: Department of Neurological Surgery, Columbia University Medical Center, New York, NY, USA. Electronic address: dpaintonbray@gmail.com.
authors.forename: David P
authors.initials: DP
authors.lastname: Bray
authors.affiliation: Department of Neurological Surgery, Columbia University Medical Center, New York, NY, USA.
authors.forename: Jason A
authors.initials: JA
authors.lastname: Ellis
authors.affiliation: Department of Neurological Surgery, Columbia University Medical Center, New York, NY, USA.
authors.forename: Sean D
authors.initials: SD
authors.lastname: Lavine
authors.affiliation: Department of Neurological Surgery, Columbia University Medical Center, New York, NY, USA.
authors.forename: Philip M
authors.initials: PM
authors.lastname: Meyers
authors.affiliation: Department of Neurological Surgery, Columbia University Medical Center, New York, NY, USA.
authors.forename: E Sander
authors.initials: ES
authors.lastname: Connolly
mesh_terms: D002533:Cerebral Angiography / Q000706:statistics & numerical data*; D000072226:Computed Tomography Angiography / Q000706:statistics & numerical data*; D064420:Drug-Related Side Effects and Adverse Reactions / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009518:New York / Q000453:epidemiology; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use*; D015995:Prevalence; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013345:Subarachnoid Hemorrhage / Q000000981:diagnostic imaging* / Q000453:epidemiology*
chemical_list: D010975:Platelet Aggregation Inhibitors
keywords: Aneurysm; Aspirin; Clopidogrel; Intracranial hemorrhage; Stroke