title: Occurrence of hemispheric and retinal ischemia in atrial fibrillation compared with carotid stenosis.
abstract: OBJECTIVE
  The goal of this study was to examine the hypotheses that retinal ischemia is caused more often by carotid atherosclerosis than by atrial fibrillation and that the odds of retinal events compared with hemispheric events increase with worsening carotid stenosis.
  
  
  METHODS
  We used data from the Stroke Prevention in Atrial Fibrillation (SPAF) I through III trials and North American Symptomatic Carotid Endarterectomy Trial (NASCET), calculating hemispheric:retinal (H:R) odds for the territory of ischemic events during follow-up in patients with atrial fibrillation and medically treated 50% to 99% carotid stenosis or occlusion in the respective trials.
  
  
  RESULTS
  The H:R odds were 25:1 in the SPAF aspirin-assigned patients and 2:1 for NASCET vessels. In NASCET patients, the H:R odds of recurrent ischemic events were 1:4 for vessels randomized initially for retinal symptoms compared with 6:1 for those randomized for hemispheric events (significant difference; P<0.001). Moreover, the H:R odds of first events in the territory of the contralateral asymptomatic artery were 1:1 if the randomized vessel had retinal symptoms compared with 4:1 if the randomized vessel had hemispheric symptoms (significant difference; P<0.01). Increasing carotid stenosis in the 50% to 99% range had no effect on H:R odds (P=0.8).
  
  
  CONCLUSIONS
  These findings confirm that retinal symptoms are more typical of carotid stenosis. Hemodynamic effects do not appear to be more important in the pathogenesis of retinal events than hemispheric ones in carotid stenosis. The retinal versus hemispheric location of initial symptoms is strongly predictive of the location of subsequent events in patients with carotid stenosis, even when new symptoms are contralateral to the original ones.
authors.affiliation: Hennepin County Medical Center and University of Minnesota, Minneapolis 55415, USA. ander012@tc.umn.edu
authors.forename: D C
authors.initials: DC
authors.lastname: Anderson
authors.forename: L J
authors.initials: LJ
authors.lastname: Kappelle
authors.forename: M
authors.initials: M
authors.lastname: Eliasziw
authors.forename: V L
authors.initials: VL
authors.lastname: Babikian
authors.forename: L A
authors.initials: LA
authors.lastname: Pearce
authors.forename: H J M
authors.initials: HJ
authors.lastname: Barnett
mesh_terms: D000368:Aged; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use; D000925:Anticoagulants / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000453:epidemiology*; D002545:Brain Ischemia / Q000453:epidemiology*; D016893:Carotid Stenosis / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000628:therapy; D015897:Comorbidity; D005260:Female; D006801:Humans; D002546:Ischemic Attack, Transient / Q000453:epidemiology; D008297:Male; D009656:North America / Q000453:epidemiology; D016017:Odds Ratio; D011446:Prospective Studies; D016032:Randomized Controlled Trials as Topic / Q000706:statistics & numerical data; D015356:Retinal Artery Occlusion / Q000453:epidemiology; D012164:Retinal Diseases / Q000453:epidemiology*; D014463:Ultrasonography
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D000925:Anticoagulants