title: The effect and safety of the antithrombotic therapies in patients with atrial fibrillation and CHADS score 1.
abstract: BACKGROUND
  The revised ACC/AHA/ESC 2006 guideline recommends either aspirin or warfarin for the prevention of ischemic stroke in patients with atrial fibrillation (AF) in CHADS(2) score 1. We hypothesized that warfarin is superior to aspirin therapy for the prevention of stroke without increasing bleeding complication in AF patients with CHADS(2) score 1.
  
  
  RESULTS
  Among 1,502 patients (mean 62.4 +/- 13.8 years old, male 65.4%) who were treated for nonvalvular AF without previous stroke, the number of patients with CHADS(2) score 1 was 422 (62.9 +/- 10.7 years old, male 290 [68.7%]) and their antithrombotic therapies were as follows: warfarin (n = 143), aspirin (n = 124), other antiplatelet (n = 45), and no antithrombosis (none: n = 110). We reviewed the incidences of ischemic stroke, mortality, and bleeding complications during the follow-up period. Results were: (1) during 22.3 +/- 17.8 months of follow-up, the incidence of ischemic stroke was significantly lower in warfarin (6 patients, 4.2%, mean international normalized ratio [INR] 2.0 +/- 0.5 IU) than in aspirin (16 patients, 12.9%, P = 0.008) than none (23 patients, 20.9%, P < 0.001) without differences in all-cause mortality. (2) The incidence of major bleeding (decrease in hemoglobin >or=2 g/dL, requiring hospitalization or red blood cell transfusion >or=2 pints) was not different between warfarin (2.1%) and aspirin (0.8%, P = NS), but minor bleeding was more common in warfarin (10.5%) than in aspirin (2.4%, P = 0.007).
  
  
  CONCLUSIONS
  In AF patients with CHADS(2) score 1, warfarin was better to prevent ischemic stroke than aspirin without increasing the incidence of major bleeding complications. However, the incidence of minor bleeding was higher in the warfarin group than the aspirin group.
authors.affiliation: Yonsei University Health System, Seoul, Republic of Korea.
authors.forename: Byung Ho
authors.initials: BH
authors.lastname: Lee
authors.forename: Jae Seok
authors.initials: JS
authors.lastname: Park
authors.forename: Jae Hyung
authors.initials: JH
authors.lastname: Park
authors.forename: Jong Seung
authors.initials: JS
authors.lastname: Park
authors.forename: Jae Jin
authors.initials: JJ
authors.lastname: Kwak
authors.forename: Eui Seock
authors.initials: ES
authors.lastname: Hwang
authors.forename: Sook Kyoung
authors.initials: SK
authors.lastname: Kim
authors.forename: Dong Hoon
authors.initials: DH
authors.lastname: Choi
authors.forename: Young-Hoon
authors.initials: YH
authors.lastname: Kim
authors.forename: Hui-Nam
authors.initials: HN
authors.lastname: Pak
mesh_terms: D000368:Aged; D000925:Anticoagulants / Q000009:adverse effects / Q000627:therapeutic use; D001241:Aspirin / Q000009:adverse effects / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000188:drug therapy* / Q000401:mortality / Q000503:physiopathology; D002545:Brain Ischemia / Q000150:complications / Q000453:epidemiology / Q000473:pathology; D005260:Female; D005343:Fibrinolytic Agents / Q000009:adverse effects* / Q000627:therapeutic use*; D005500:Follow-Up Studies; D006470:Hemorrhage / Q000139:chemically induced / Q000453:epidemiology; D006801:Humans; D019934:International Normalized Ratio; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D010975:Platelet Aggregation Inhibitors / Q000009:adverse effects / Q000627:therapeutic use; D016016:Proportional Hazards Models; D012044:Regression Analysis; D012189:Retrospective Studies; D018570:Risk Assessment; D020521:Stroke / Q000453:epidemiology / Q000209:etiology / Q000473:pathology; D014859:Warfarin / Q000009:adverse effects / Q000627:therapeutic use
chemical_list: D000925:Anticoagulants; D005343:Fibrinolytic Agents; D010975:Platelet Aggregation Inhibitors; D014859:Warfarin; D001241:Aspirin