title: A Model for Predicting Persistent Elevation of Factor VIII among Patients with Acute Ischemic Stroke.
abstract: OBJECTIVE
  Elevated levels of coagulation factor VIII (FVIII) may persist independent of the acute-phase response; however, this relationship has not been investigated relative to acute ischemic stroke (AIS). We examined the frequency and predictors of persistently elevated FVIII in AIS patients.
  
  
  METHODS
  AIS patients admitted between July 2008 and May 2014 with elevated baseline FVIII levels and repeat FVIII levels drawn for more than 7 days postdischarge were included. The patients were dichotomized by repeat FVIII level for univariate analysis at 150% and 200% activity thresholds. An adjusted model was developed to predict the likelihood of persistently elevated FVIII levels.
  
  
  RESULTS
  Among 1616 AIS cases, 98 patients with elevated baseline FVIII had repeat FVIII levels. Persistent FVIII elevation was found in more than 75% of patients. At the 150% threshold, the prediction score ranged from 0 to 7 and included black race, female sex, prior stroke, hyperlipidemia, smoking, baseline FVIII > 200%, and baseline von Willebrand factor (vWF) level greater than 200%. At the 200% threshold, the prediction score ranged from 0-5 and included female sex, prior stroke, diabetes mellitus, baseline FVIII level greater 200%, and baseline vWF level greater than 200%. For each 1-point increase in score, the odds of persistent FVIII at both the 150% threshold (odds ratio [OR] = 10.4, 95% confidence interval [CI] 1.63-66.9, P = .0134) and 200% threshold (OR = 10.2, 95% CI 1.82-57.5, P = .0083) increased 10 times.
  
  
  CONCLUSIONS
  Because an elevated FVIII level confers increased stroke risk, our model for anticipating a persistently elevated FVIII level may identify patients at high risk for recurrent stroke. FVIII may be a target for secondary stroke prevention.
authors.affiliation: Stroke Program, Department of Neurology, Tulane University School of Medicine, New Orleans, Louisiana; Department of Epidemiology, Tulane School of Public Health and Tropical Medicine, New Orleans, Louisiana.
authors.forename: Alyana A
authors.initials: AA
authors.lastname: Samai
authors.affiliation: Department of Epidemiology, University of Alabama at Birmingham, Birmingham, Alabama; Department of Neurology, Columbia University, New York, New York.
authors.forename: Amelia K
authors.initials: AK
authors.lastname: Boehme
authors.affiliation: Stroke Program, Department of Neurology, Tulane University School of Medicine, New Orleans, Louisiana.
authors.forename: Amir
authors.initials: A
authors.lastname: Shaban
authors.affiliation: Stroke Program, Department of Neurology, Tulane University School of Medicine, New Orleans, Louisiana.
authors.forename: Alexander J
authors.initials: AJ
authors.lastname: George
authors.affiliation: Stroke Program, Department of Neurology, Tulane University School of Medicine, New Orleans, Louisiana.
authors.forename: Lauren
authors.initials: L
authors.lastname: Dowell
authors.affiliation: Stroke Program, Department of Neurology, Tulane University School of Medicine, New Orleans, Louisiana.
authors.forename: Dominique J
authors.initials: DJ
authors.lastname: Monlezun
authors.affiliation: Section of Hematology/Oncology, Department of Medicine, Tulane University School of Medicine, New Orleans, Louisiana.
authors.forename: Cindy
authors.initials: C
authors.lastname: Leissinger
authors.affiliation: Stroke Program, Department of Neurology, Tulane University School of Medicine, New Orleans, Louisiana.
authors.forename: Laurie
authors.initials: L
authors.lastname: Schluter
authors.affiliation: Stroke Program, Department of Neurology, Tulane University School of Medicine, New Orleans, Louisiana.
authors.forename: Ramy
authors.initials: R
authors.lastname: El Khoury
authors.affiliation: Stroke Program, Department of Neurology, Tulane University School of Medicine, New Orleans, Louisiana. Electronic address: smartin2@tulane.edu.
authors.forename: Sheryl
authors.initials: S
authors.lastname: Martin-Schild
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000097:blood*; D005169:Factor VIII / Q000032:analysis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D011379:Prognosis; D012307:Risk Factors; D020521:Stroke / Q000097:blood*; D055815:Young Adult
chemical_list: D005169:Factor VIII
keywords: Ischemic stroke; biomarker; blood coagulation; factor VIII; thrombosis