title: An index to identify stroke-related vs incidental patent foramen ovale in cryptogenic stroke.
abstract: OBJECTIVE
  We aimed to create an index to stratify cryptogenic stroke (CS) patients with patent foramen ovale (PFO) by their likelihood that the stroke was related to their PFO.
  
  
  METHODS
  Using data from 12 component studies, we used generalized linear mixed models to predict the presence of PFO among patients with CS, and derive a simple index to stratify patients with CS. We estimated the stratum-specific PFO-attributable fraction and stratum-specific stroke/TIA recurrence rates.
  
  
  RESULTS
  Variables associated with a PFO in CS patients included younger age, the presence of a cortical stroke on neuroimaging, and the absence of these factors: diabetes, hypertension, smoking, and prior stroke or TIA. The 10-point Risk of Paradoxical Embolism score is calculated from these variables so that the youngest patients with superficial strokes and without vascular risk factors have the highest score. PFO prevalence increased from 23% (95% confidence interval [CI]: 19%-26%) in those with 0 to 3 points to 73% (95% CI: 66%-79%) in those with 9 or 10 points, corresponding to attributable fraction estimates of approximately 0% to 90%. Kaplan-Meier estimated stroke/TIA 2-year recurrence rates decreased from 20% (95% CI: 12%-28%) in the lowest Risk of Paradoxical Embolism score stratum to 2% (95% CI: 0%-4%) in the highest.
  
  
  CONCLUSIONS
  Clinical characteristics identify CS patients who vary markedly in PFO prevalence, reflecting clinically important variation in the probability that a discovered PFO is likely to be stroke-related vs incidental. Patients in strata more likely to have stroke-related PFOs have lower recurrence risk.
authors.affiliation: Institute for Clinical Research and Health Policy Studies, Tufts Medical Center/Tufts University School of Medicine, Boston, MA, USA. Dkent1@tuftsmedicalcenter.org
authors.forename: David M
authors.initials: DM
authors.lastname: Kent
authors.forename: Robin
authors.initials: R
authors.lastname: Ruthazer
authors.forename: Christian
authors.initials: C
authors.lastname: Weimar
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Mas
authors.forename: Joaquín
authors.initials: J
authors.lastname: Serena
authors.forename: Shunichi
authors.initials: S
authors.lastname: Homma
authors.forename: Emanuele
authors.initials: E
authors.lastname: Di Angelantonio
authors.forename: Marco R
authors.initials: MR
authors.lastname: Di Tullio
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Lutz
authors.forename: Mitchell S V
authors.initials: MS
authors.lastname: Elkind
authors.forename: John
authors.initials: J
authors.lastname: Griffith
authors.forename: Cheryl
authors.initials: C
authors.lastname: Jaigobin
authors.forename: Heinrich P
authors.initials: HP
authors.lastname: Mattle
authors.forename: Patrik
authors.initials: P
authors.lastname: Michel
authors.forename: Marie-Louise
authors.initials: ML
authors.lastname: Mono
authors.forename: Krassen
authors.initials: K
authors.lastname: Nedeltchev
authors.forename: Federica
authors.initials: F
authors.lastname: Papetti
authors.forename: David E
authors.initials: DE
authors.lastname: Thaler
mesh_terms: D000368:Aged; D005260:Female; D054092:Foramen Ovale, Patent / Q000150:complications* / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012008:Recurrence; D012307:Risk Factors; D020521:Stroke / Q000145:classification* / Q000209:etiology*