title: Preconditioning effect on cerebral vasospasm in patients with aneurysmal subarachnoid hemorrhage.
abstract: BACKGROUND
  Recent experimental evidence indicates that endogenous mechanisms against cerebral vasospasm can be induced via preconditioning.
  
  
  OBJECTIVE
  To determine whether these vascular protective mechanisms are also present in vivo in humans with aneurysmal subarachnoid hemorrhage.
  
  
  METHODS
  A multicenter retrospective cohort of patients with aneurysmal subarachnoid hemorrhage was examined for ischemic preconditioning stimulus: preexisting steno-occlusive cerebrovascular disease (CVD) and/or previous cerebral infarct. Generalized estimating equation models were performed to determine the effect of the preconditioning stimulus on the primary end points of radiographic vasospasm, symptomatic vasospasm, and vasospasm-related delayed cerebral infarction and the secondary end point of discharge modified Rankin Scale score.
  
  
  RESULTS
  Of 1043 patients, 321 (31%) had preexisting CVD and 437 (42%) had radiographic vasospasm. Patients with preexisting CVD were less likely to develop radiographic vasospasm (odds ratio = 0.67; 95% confidence interval = 0.489-0.930; P = .02) but had no differences in other end points. In terms of the secondary end point, patients with preexisting CVD did not differ significantly from patients without preexisting CVD in mortality or unfavorable outcome in multivariate analyses, although patients with preexisting CVD were marginally more likely to die (P = .06).
  
  
  CONCLUSIONS
  This retrospective case-control study suggests that endogenous protective mechanisms against cerebral vasospasm-a preconditioning effect-may exist in humans, although these results could be the effect of atherosclerosis or some combination of preconditioning and atherosclerosis. Additional studies investigating the potential of preconditioning in aneurysmal subarachnoid hemorrhage are warranted.
authors.affiliation: *Department of Neurosurgery, Bucheon St. Mary's Hospital, Catholic University of Korea, Bucheon, Republic of Korea; ‡Department of Neurosurgery, Washington University School of Medicine, St. Louis, Missouri; §Neurovascular Service, Massachusetts General Hospital, Boston, Massachusetts; ¶Department of Radiology, UT Southwestern Medical Center, Dallas, Texas; ‖Department of Neurosurgery, Virginia Commonwealth University, Richmond, Virginia; #Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona; **Department of Neurosurgery, University of Florida, Gainesville, Florida.
authors.forename: Young Woo
authors.initials: YW
authors.lastname: Kim
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Zipfel
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Ogilvy
authors.forename: Katie L
authors.initials: KL
authors.lastname: Pricola
authors.forename: Babu G
authors.initials: BG
authors.lastname: Welch
authors.forename: Nabeel
authors.initials: N
authors.lastname: Shakir
authors.forename: Bhuvic
authors.initials: B
authors.lastname: Patel
authors.forename: John F
authors.initials: JF
authors.lastname: Reavey-Cantwell
authors.forename: Craig R
authors.initials: CR
authors.lastname: Kelman
authors.forename: Felipe C
authors.initials: FC
authors.lastname: Albuquerque
authors.forename: M Yashar S
authors.initials: MY
authors.lastname: Kalani
authors.forename: Brian L
authors.initials: BL
authors.lastname: Hoh
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D002544:Cerebral Infarction / Q000453:epidemiology*; D002561:Cerebrovascular Disorders / Q000453:epidemiology*; D015897:Comorbidity; D005260:Female; D006801:Humans; D019194:Ischemic Preconditioning; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013345:Subarachnoid Hemorrhage / Q000150:complications*; D020301:Vasospasm, Intracranial / Q000453:epidemiology* / Q000209:etiology*