title: Additive effect of the metabolic syndrome score to the conventional CHADS₂ score for the thromboembolic risk stratification of patients with atrial fibrillation.
abstract: BACKGROUND
  The CHA₂DS₂-VASC scoring scheme may not be better than the CHADS₂ scoring scheme in predicting thromboembolic risk for patients with atrial fibrillation (AF) in Asians. Metabolic syndrome is associated with an increased risk of thrombosis.
  
  
  OBJECTIVE
  To evaluate whether metabolic syndrome offers incremental information over the CHADS₂ scheme in predicting thromboembolic risk for patients with AF in the Taiwanese population.
  
  
  METHODS
  The study population consisted of 721 consecutive patients with AF who had been followed up for a median of 10.8 years. Thromboembolic end points were defined as ischemic stroke/transient ischemic accident and peripheral embolisms. Clinical factors associated with thromboembolic end points were identified by Cox regression analysis. Different scoring systems were compared by receiver operating characteristic (ROC) analysis.
  
  
  RESULTS
  We found that components in the CHADS₂ scheme were associated with an increased risk of thromboembolism. The CHA2DS₂-VASC scheme did not provide information additional to that provided by the CHADS₂ scheme on thromboembolism risk (ROC area: 0.670 vs 0.665; P > .05). Metabolic syndrome components were also associated with increased risk of thromboembolism. The incident thromboembolic rate increased incrementally when metabolic syndrome score increased. Additional metabolic syndrome components provide additional information to the CHADS₂ scheme on thromboembolism risk (ROC area: 0.670 vs 0.729; P = .034). We therefore proposed a new scoring scheme called CHADS₂-MS scoring scheme. In patients with low to intermediate CHADS₂ scores (0-1), the use of the CHADS₂-MS score may additionally identify patients with high-risk AF for future thromboembolism.
  
  
  CONCLUSIONS
  We, for the first time, demonstrated that metabolic syndrome components were associated with thromboembolic risk in Taiwanese patients with AF. In addition to the conventional CHADS₂ scheme, the calculation of the CHADS₂-MS score provides additional information on stroke risk assessment.
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital Yun-Lin Branch, Yun-Lin, Taiwan; Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan. Electronic address: cttsai1999@gmail.com.
authors.forename: Chia-Ti
authors.initials: CT
authors.lastname: Tsai
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Lotung Poh-Ai Hospital, Yilan, Taiwan.
authors.forename: Shu-Hsuan
authors.initials: SH
authors.lastname: Chang
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital Yun-Lin Branch, Yun-Lin, Taiwan.
authors.forename: Sheng-Nan
authors.initials: SN
authors.lastname: Chang
authors.affiliation: Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Juey-Jen
authors.initials: JJ
authors.lastname: Hwang
authors.affiliation: Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Cho-Kai
authors.initials: CK
authors.lastname: Wu
authors.affiliation: Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Yi-Chih
authors.initials: YC
authors.lastname: Wang
authors.affiliation: Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Chuen-Den
authors.initials: CD
authors.lastname: Tseng
authors.affiliation: Department of Anesthesiology, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Huei-Ming
authors.initials: HM
authors.lastname: Yeh
authors.affiliation: Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Ling-Ping
authors.initials: LP
authors.lastname: Lai
authors.affiliation: Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan; Department of Laboratory Medicine, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Fu-Tien
authors.initials: FT
authors.lastname: Chiang
authors.affiliation: Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan. Electronic address: jiunnlee@ntuh.gov.tw.
authors.forename: Jiunn-Lee
authors.initials: JL
authors.lastname: Lin
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000150:complications*; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D024821:Metabolic Syndrome / Q000150:complications*; D008875:Middle Aged; D018570:Risk Assessment; D012307:Risk Factors; D013624:Taiwan; D013923:Thromboembolism / Q000209:etiology*
keywords: Atrial fibrillation; Metabolic syndrome; Stroke; Thromboembolism