title: Validation of contemporary stroke and bleeding risk stratification scores in non-anticoagulated Chinese patients with atrial fibrillation.
abstract: BACKGROUND
  Risk stratification schemes assessing stroke and thromboembolism (stroke/TE) and bleeding relating to atrial fibrillation (AF) have largely been derived and validated in Western populations. We assessed risk factors that constitute scores for assessing stroke/TE (CHADS2, CHA2DS2-VASc) and bleeding (HAS-BLED), and the predictive value of these scores in a large cohort of Chinese patients with AF.
  
  
  RESULTS
  We studied 1034 AF patients (27.1% female, median age 75; 85.6% non-anticoagulated) with mean follow-up of 1.9 years. On multivariate analysis, vascular disease was independently associated with stroke/TE in non-anticoagulated patients (p=0.04). In patients with a CHADS2 or CHA2DS2-VASc score=1, the rate of stroke/TE was 2.9% and 0.9% respectively, but in patients at "high risk" (scores ≥ 2), this rate was 4.6% and 4.5%, respectively. The c-statistics for predicting stroke/TE with CHADS2 and CHA2DS2-VASc were 0.58 (p=0.109) and 0.72 (p<0.001), respectively. Compared to CHADS2, the use of CHA2DS2-VASc would result in a Net Reclassification Improvement (NRI) of 16.6% (p=0.009) and an Integrated Discrimination Improvement (IDI) of 1.1% (p=0.002). Cumulative survival of the patients with a CHA2DS2-VASc score≥2 was decreased compared to those with a CHA2DS2-VASc score 0-1 (p<0.001), but the CHADS2 was not predictive of mortality. There was an increased risk of major bleeding with increasing HAS-BLED score (c-statistic 0.61, 95% CI: 0.51-0.71, p=0.042).
  
  
  CONCLUSIONS
  Vascular disease was a strong independent predictor of stroke/TE in Chinese patients with AF. The CHA2DS2-VASc score performed better than CHADS2 in predicting stroke/TE in this Chinese AF population. Cumulative survival of the patients at high risk with the CHA2DS2-VASc score (but not using CHADS2) was significantly decreased.
authors.affiliation: Department of Geriatric Cardiology, Chinese PLA General Hospital, Beijing, China; Haemostasis, Thrombosis and Vascular Biology Unit, University of Birmingham Centre for Cardiovascular Sciences, City Hospital, Birmingham, United Kingdom.
authors.forename: Yutao
authors.initials: Y
authors.lastname: Guo
authors.forename: Stavros
authors.initials: S
authors.lastname: Apostolakis
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Blann
authors.forename: Haijun
authors.initials: H
authors.lastname: Wang
authors.forename: Xiaoning
authors.initials: X
authors.lastname: Zhao
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.forename: Dexian
authors.initials: D
authors.lastname: Zhang
authors.forename: Jingling
authors.initials: J
authors.lastname: Ma
authors.forename: Yutang
authors.initials: Y
authors.lastname: Wang
authors.forename: Gregory Y H
authors.initials: GY
authors.lastname: Lip
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People / Q000208:ethnology; D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000208:ethnology / Q000503:physiopathology; D001777:Blood Coagulation / Q000502:physiology; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006470:Hemorrhage / Q000175:diagnosis* / Q000208:ethnology / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D020521:Stroke / Q000175:diagnosis* / Q000208:ethnology / Q000503:physiopathology