title: Prediction of stroke or TIA in patients without atrial fibrillation using CHADS2 and CHA2DS2-VASc scores.
abstract: OBJECTIVE
  To determine the accuracy of CHADS2 and CHA2DS2-VASc tools for predicting ischaemic stroke or transient ischaemic attack (TIA) and death in patients without a history of atrial fibrillation or flutter (AF).
  
  
  METHODS
  The study included 20 970 patients without known AF enrolled in the Alberta Provincial Project for Outcomes Assessment in Coronary Heart disease (APPROACH) prospective registry who were discharged after an acute coronary syndrome (ACS) between 2005 and 2011. The outcome measures were incident ischaemic stroke, TIA or death from any cause.
  
  
  RESULTS
  Over a median follow-up of 4.1 years, 453 patients (2.2%) had a stroke (n=297) or TIA (n=156) and 1903 (9.0%) died. The incidence of stroke or TIA increased with increases in each risk score (p<0.001), with an absolute annual incidence ≥1% with CHADS2 ≥3 or CHA2DS2-VASc ≥4. Both CHADS2 and CHA2DS2-VASc scores had acceptable discrimination performance (C-statistic=0.68 and 0.71, respectively). The mortality rate was also greater in patients with higher CHADS2 and CHA2DS2-VASc scores (p<0.0001).
  
  
  CONCLUSIONS
  In patients with ACS but no AF, the CHADS2 and CHA2DS2-VASc scores predict ischaemic stroke/TIA events with similar accuracy to that observed in historical populations with non-valvular AF, but with lower absolute event rates. Further study of the utility of the CHADS2 and CHA2DS2-VASc scores for the assessment of thromboembolic risk and selection of antithrombotic therapy in patients without AF is warranted.
authors.affiliation: Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta, Canada.
authors.forename: L Brent
authors.initials: LB
authors.lastname: Mitchell
authors.affiliation: Department of Community Health Sciences, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Danielle A
authors.initials: DA
authors.lastname: Southern
authors.affiliation: Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Diane
authors.initials: D
authors.lastname: Galbraith
authors.affiliation: Departments of Community Health Sciences and Medicine, University of Calgary, Calgary, Alberta, Canada.
authors.forename: William A
authors.initials: WA
authors.lastname: Ghali
authors.affiliation: Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Merril
authors.initials: M
authors.lastname: Knudtson
authors.affiliation: Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Wilton
mesh_terms: D054058:Acute Coronary Syndrome / Q000150:complications* / Q000453:epidemiology / Q000628:therapy; D000367:Age Factors; D000368:Aged; D002170:Canada / Q000453:epidemiology; D015897:Comorbidity; D003661:Decision Support Techniques; D003920:Diabetes Mellitus / Q000453:epidemiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D002546:Ischemic Attack, Transient / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D009026:Mortality; D017063:Outcome Assessment, Health Care; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use; D057216:Propensity Score; D012107:Research Design / Q000592:standards; D018570:Risk Assessment / Q000379:methods / Q000592:standards; D012737:Sex Factors; D020521:Stroke / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control
chemical_list: D010975:Platelet Aggregation Inhibitors