title: Hypertension before and after posterior circulation infarction: analysis of data from the South London Stroke Register.
abstract: BACKGROUND
  Postmortem data have shown that blood pressure before death correlates more closely with a narrowing of the vertebral arteries than any other vessel studied. This study explores a possible association between hypertension, both before and after posterior circulation infarction (POCI) compared to anterior circulation infarction (ACI).
  
  
  METHODS
  Patients with a first-ever stroke enrolled in the South London Stroke Register between 2000 and 2006 were included. Chi-square tests and multivariable logistic regression were used to compare risk factors including hypertension, sex, smoking history, diabetes, and hypercholesterolemia in patients with POCI compared to ACI. Chi-square testing was used to compare the incidence of newly diagnosed hypertension after POCI and ACI. Absolute blood pressure readings recorded before stroke and 7 days after stroke were also compared between groups.
  
  
  RESULTS
  On multivariable analysis, POCI was significantly associated with male sex (odds ratio [OR] 2.24; 95% confidence interval [CI] 1.55-3.22; P < .001) and hypertension (OR 1.69; 95% CI 1.15-2.50; P = .008). After stroke, patients with POCI were more likely to be newly diagnosed with hypertension during a 1-year follow-up period (OR 2.15; 95% CI 1.20-3.86; P = .009) and as an inpatient (OR 3.27; 95% CI 1.49-7.13; P = .002). Systolic blood pressure was significantly higher in the POCI group before stroke (152 v 146 mm Hg; P = .027). Diastolic blood pressure was significantly higher 7 days poststroke (81 v 74 mm Hg; P = .01) in patients not previously diagnosed with hypertension.
  
  
  CONCLUSIONS
  This study has shown a significant association between hypertension before and after POCI compared to ACI. We believe further investigation with brainstem imaging and recordings of sympathetic nervous system activity after stroke is warranted.
authors.affiliation: Department of Physiology and Pharmacology, University of Bristol, Oxhey Watford, Herts, United Kingdom. matthew.cates@doctors.org.uk
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Cates
authors.forename: Julian F R
authors.initials: JF
authors.lastname: Paton
authors.forename: Nigel C
authors.initials: NC
authors.lastname: Smeeton
authors.forename: Charles D A
authors.initials: CD
authors.lastname: Wolfe
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure; D020520:Brain Infarction / Q000145:classification / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D002560:Cerebrovascular Circulation; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D006973:Hypertension / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D016015:Logistic Models; D008131:London / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors