title: Young Male Patients with Atrial Fibrillation and CHA2DS2-VASc Score of 1 May Not Need Anticoagulants: A Nationwide Population-Based Study.
abstract: BACKGROUND
  It is unclear whether oral anticoagulants are beneficial for atrial fibrillation (AF) patients with low CHA2DS2-VASc score. Age could be important in determining the risk of thromboembolism in low risk AF patients (CHA2DS2-VASc score of 1 for male or 2 for female).
  
  
  METHODS
  The Taiwan National Health Insurance Research Database (NHIRD) was used and 27,521 AF patients with CHA2DS2-VASc score of 1 (male) or 2 (female) not receiving anticoagulants were acquired as the study cohort, which were classified into three age groups: 20-49, 50-64, and 65-74 years. The clinical endpoint was the occurrence of ischemic thromboembolism within one year of follow up.
  
  
  RESULTS
  During the follow-up of 0.94 ± 0.19 years, 385 (2.19%) male patients experienced ischemic thromboembolism, with annual rate of 2.32%. The annual risk ranged from 1.29%, 2.43% to 2.77% for male patients aged 20-49, 50-64 and 65-74 years respectively. Of the female patients, 218 (2.20%) experienced clinical event with annual rate of 2.32%. The annual risk increased from 1.87%, 2.28% to 2.64% for female patients aged 20-49, 50-64 and 65-74 years respectively. There was no difference in risk between the male patients aged 20-49 years with CHA2DS2-VASc score of 1 and overall male patients with CHA2DS2-VASc score of 0. (P = 0.631) The female patients aged 20-49 years with CHA2DS2-VASc score of 2 was associated with a higher risk of thromboembolic events than overall female patients with CHA2DS2-VASc score of 1 (HR = 1.93; P = 0.008).
  
  
  CONCLUSIONS
  Age is important in determining the risk of thromboembolism in AF patients with single risk factor. In male patients <50 years old with CHA2DS2-VASc score of 1, the risk of ischemic thromboembolism was low. Considering the benefits and the risk of bleeding, oral anticoagulation therapy may not be favorable in these patients.
authors.affiliation: The Cardiovascular Department, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan.|College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Yi-Hsin
authors.initials: YH
authors.lastname: Chan
authors.affiliation: The Cardiovascular Department, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan.|College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Lung-Sheng
authors.initials: LS
authors.lastname: Wu
authors.affiliation: The Cardiovascular Department, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan.|College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Shang-Hung
authors.initials: SH
authors.lastname: Chang
authors.affiliation: The Cardiovascular Department, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan.|College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Hsin-Fu
authors.initials: HF
authors.lastname: Lee
authors.affiliation: Department of Public Health, College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Jia-Rou
authors.initials: JR
authors.lastname: Liu
authors.affiliation: Department of Public Health, College of Medicine, Chang Gung University, Taoyuan, Taiwan.|Biostatistics Core Laboratory, Molecular Medicine Research Center, Chang Gung University, Taoyuan, Taiwan.|Division of of Rheumationalogy and Allergy and Immunology, Department of Internal Medicine, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan.
authors.forename: Lai-Chu
authors.initials: LC
authors.lastname: See
authors.affiliation: The Cardiovascular Department, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan.|College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Yung-Hsin
authors.initials: YH
authors.lastname: Yeh
authors.affiliation: The Cardiovascular Department, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan.|College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Chi-Tai
authors.initials: CT
authors.lastname: Kuo
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000925:Anticoagulants / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000150:complications / Q000188:drug therapy*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018570:Risk Assessment; D012307:Risk Factors; D013624:Taiwan; D013923:Thromboembolism / Q000209:etiology / Q000517:prevention & control*; D055815:Young Adult
chemical_list: D000925:Anticoagulants