title: Brain edema formation is associated with the time rate of blood pressure variation in acute stroke patients.
abstract: OBJECTIVE
  Both brain edema and increased blood pressure (BP) variability are associated with poor outcome after stroke. The aim of the present study was to evaluate a possible association between edema formation and a relatively new index of BP variability defined as time rate (TR) of BP variation.
  
  
  METHODS
  A total of 128 first-ever acute stroke patients underwent 24-h ambulatory BP monitoring within 24 h from onset of stroke. All patients were imaged with computed tomography scan on admission and after 5 days to determine the presence of brain edema. The TR of BP variation was defined as the first derivative of the BP values against time. Known risk factors and neurological severity on admission were documented.
  
  
  RESULTS
  The 24-h TR of systolic BP variation was significantly higher (P<0.001) in stroke patients with brain edema (0.69±0.15 mmHg/min) compared with those without edema (0.57±0.12 mmHg/min). The multivariate logistic regression model showed that a 0.1 mmHg/min increase in the TR of 24-h systolic BP variation was associated with a 13.9% increased probability of the presence of brain edema (odds ratio=1.139, 95% confidence interval: 1.058-1.225, P<0.001), after adjusting for history of diabetes mellitus, hypercholesterolemia, type of stroke, neurological deficit, and 24-h systolic BP.
  
  
  CONCLUSIONS
  Increased values of 24-h TR of systolic BP variation are associated independently with formation of edema in acute stroke patients.
authors.affiliation: Department of Clinical Therapeutics, Medical School of Athens, Alexandra Hospital, Athens, Greece. sskalidi@hotmail.com
authors.forename: Sophia J
authors.initials: SJ
authors.lastname: Skalidi
authors.forename: Efstathios D
authors.initials: ED
authors.lastname: Manios
authors.forename: Kimon S
authors.initials: KS
authors.lastname: Stamatelopoulos
authors.forename: Gerasimos
authors.initials: G
authors.lastname: Barlas
authors.forename: Fotios
authors.initials: F
authors.lastname: Michas
authors.forename: Savvas T
authors.initials: ST
authors.lastname: Toumanidis
authors.forename: Konstantinos N
authors.initials: KN
authors.lastname: Vemmos
authors.forename: Nikolaos A
authors.initials: NA
authors.lastname: Zakopoulos
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure; D018660:Blood Pressure Monitoring, Ambulatory; D001921:Brain / Q000473:pathology*; D001929:Brain Edema / Q000209:etiology* / Q000473:pathology*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012307:Risk Factors; D020521:Stroke / Q000150:complications*