title: Reduced cerebrovascular reserve at CO2 BOLD MR imaging is associated with increased risk of periinterventional ischemic lesions during carotid endarterectomy or stent placement: preliminary results.
abstract: OBJECTIVE
  To determine whether any initial reductions in cardiovascular reserve (CVR) normalize after carotid revascularization and-because reduced CVR represents a risk factor for ischemic events-whether patients who develop periinterventional infarction have more severely reduced pretreatment CVR than those who do not.
  
  
  METHODS
  Ethics committee approval and informed consent were obtained. Twenty-four consecutive patients with symptomatic high-grade internal carotid artery stenosis (seven women; mean age, 73.1 years +/- 9.4 [standard deviation]) were recruited from a prospective, randomized trial that compared carotid artery stent placement with endarterectomy. Magnetic resonance (MR) imaging, including CO(2) blood oxygen level-dependent (BOLD) MR, was performed 1-3 days before, 1-3 days after, and 1 month after carotid revascularization (carotid artery stent placement, n = 13; carotid endarterectomy, n = 11).
  
  
  RESULTS
  Mean CVR in the ipsilateral middle cerebral artery (MCA) territory was reduced prior to treatment (mean DeltaT2* in ipsilateral territory, 1.92% +/- 1.18; mean DeltaT2* in contralateral territory, 2.28% +/- 1.15 [P < .05]) and normalized after treatment (mean DeltaT2* 1-3 days after treatment in ipsilateral territory, 2.66% +/- 1.01; that in contralateral territory, 2.48% +/- 1.27 [P > .05]; mean DeltaT2* 1 month after treatment in ipsilateral territory, 2.27% +/- 1.05; that in contralateral territory, 2.14% +/- 0.96 [P > .05]). Those patients who developed new periinterventional infarcts (n = 7 with punctate foci of restricted diffusion) had greater reduction of CVR in the ipsilateral MCA territory prior to treatment (relative reduction, 32.5% +/- 46.0; P < .05) than those who did not develop infarction (n = 17; relative reduction, 9.2% +/- 55.9).
  
  
  CONCLUSIONS
  CO(2) BOLD MR imaging could be used successfully to monitor the hemodynamic effects of carotid revascularization; initial reductions in CVR normalized after carotid revascularization. Severely reduced pretreatment CVR was associated with increased occurrence of new periinterventional therapy infarction.
authors.affiliation: Department of Diagnostic and Interventional Neuroradiology, Institute of Radiology, University Hospital Basel, Petersgraben 4, CH-4031 Basel, Switzerland. shaller@uhbs.ch
authors.forename: Sven
authors.initials: S
authors.lastname: Haller
authors.forename: Leo H
authors.initials: LH
authors.lastname: Bonati
authors.forename: Jochen
authors.initials: J
authors.lastname: Rick
authors.forename: Markus
authors.initials: M
authors.lastname: Klarhöfer
authors.forename: Oliver
authors.initials: O
authors.lastname: Speck
authors.forename: Philippe A
authors.initials: PA
authors.lastname: Lyrer
authors.forename: Deniz
authors.initials: D
authors.lastname: Bilecen
authors.forename: Stefan T
authors.initials: ST
authors.lastname: Engelter
authors.forename: Stephan G
authors.initials: SG
authors.lastname: Wetzel
mesh_terms: D000368:Aged; D002245:Carbon Dioxide / Q000097:blood; D002544:Cerebral Infarction / Q000209:etiology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D016894:Endarterectomy, Carotid; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D010100:Oxygen / Q000097:blood; D012307:Risk Factors; D015607:Stents
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen