title: Evaluation of the CHADS2 risk score on short- and long-term all-cause and cardiovascular mortality after syncope.
abstract: BACKGROUND
  Syncope risk stratification is difficult and has not been implemented clinically.
  
  
  OBJECTIVE
  The CHADS2 score can be applied as a risk stratification tool for predicting mortality after an episode of syncope.
  
  
  METHODS
  All patients discharged from emergency departments with a first-time diagnosis of syncope from 2001 to 2009 where identified from nationwide registers in Denmark and matched on sex and age with a control population. Risk of all-cause or cardiovascular death was analyzed by multivariable Cox models.
  
  
  RESULTS
  A total of 37,705 patients were included. There were a total of 7761 deaths (21%), of which 52% were cardiovascular vs 27 862 (15%) deaths in the control population. The risk of cardiovascular death was significantly increased with increasing CHADS2 score (CHADS2 score: 1-2, hazard ratio [HR]: 9.11, 95% confidence interval [CI]: 8.25-10.07; CHADS2 score: 3-4, HR: 17.32, 95% CI: 15.42-19.47; CHADS2 score: 5-6, HR: 26.66, 95% CI: 21.40-33.21) relative to CHADS2 score of 0. A CHADS2 score of 0 was associated overall with very low event rates (15.1 deaths per 1000 person-years) but was associated with increased relative risk in the syncope population compared to controls. Syncope predicted 1-week, 1-year, and long-term mortality across CHADS2 scores compared to controls but did not reach significance in CHADS2 scores of 5 to 6.
  
  
  CONCLUSIONS
  Increasing CHADS2 score significantly predicts mortality in patients discharged with a diagnosis of syncope, and a CHADS2 score of 0 was associated with a very low absolute mortality. Compared to controls, syncope was associated with increased short- and long-term mortality, particularly in the lower CHADS2 scores.
authors: Department of Cardiology, Gentofte Hospital, Hellerup, Denmark. mruwald@hotmail.com
authors: Martin Huth
authors: MH
authors: Ruwald
authors: Anne-Christine
authors: AC
authors: Ruwald
authors: Christian
authors: C
authors: Jons
authors: Morten
authors: M
authors: Lamberts
authors: Morten Lock
authors: ML
authors: Hansen
authors: Michael
authors: M
authors: Vinther
authors: Lars
authors: L
authors: Køber
authors: Christian
authors: C
authors: Torp-Pedersen
authors: Jim
authors: J
authors: Hansen
authors: Gunnar Hilmar
authors: GH
authors: Gislason
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002318:Cardiovascular Diseases / Q000175:diagnosis / Q000401:mortality*; D002423:Cause of Death; D016009:Chi-Square Distribution; D003718:Denmark / Q000453:epidemiology; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D010351:Patient Discharge; D016016:Proportional Hazards Models; D012042:Registries; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013575:Syncope / Q000175:diagnosis / Q000401:mortality*; D013997:Time Factors