title: Geographical differences in thromboembolic and bleeding risks in patients with non-valvular atrial fibrillation: An ancillary analysis from the SPORTIF trials.
abstract: BACKGROUND
  Atrial fibrillation (AF) is associated with an increased risk of stroke, and the use of oral anticoagulation reduces stroke and all-cause mortality. Geographical differences may exist in AF risk factors, risk stratification and treatment strategies.
  
  
  METHODS
  A post-hoc subgroup analysis derived from randomized controlled trials, the SPORTIF III and V trials, studying differences between European and North American warfarin-assigned non-valvular AF patients.
  
  
  RESULTS
  Of 3359 patients 41.6% (n=1397) were enrolled in Europe and 1962 (58.4%) from North America. CHA2DS2-VASc (p=0.002) and HAS-BLED (p<0.001) scores were higher in North Americans. Good anticoagulation control was more common in North American patients than Europeans. 1-Kaplan-Meier estimate curves show that North Americans had a lower risk of stroke/systemic embolic event (SEE) (p=0.012), but higher risk of myocardial infarction(MI) (p=0.007) and major bleeding (p<0.001), compared to Europeans. Cox multivariate analysis confirmed a lower stroke/SEE risk (p=0.008) and higher MI (p=0.014) and major bleeding risks (p<0.001) in North Americans.
  
  
  CONCLUSIONS
  Compared to European AF patients, North Americans had better anticoagulation control and higher thromboembolic and bleeding risk profiles. At follow-up, North American patients had lower stroke/SEE risk but higher MI and major bleeding risks compared to Europeans. Further studies are needed to understand these differences and the discordance between risk profile and lower stroke/SEE rates in North American compared to European patients.
authors.affiliation: University of Birmingham Institute of Cardiovascular Sciences, City Hospital, Birmingham, UK; Department of Internal Medicine and Medical Specialties, Sapienza-University of Rome, Rome, Italy. Electronic address: marco.proietti@uniroma1.it.
authors.forename: Marco
authors.initials: M
authors.lastname: Proietti
authors.affiliation: University of Birmingham Institute of Cardiovascular Sciences, City Hospital, Birmingham, UK; Aalborg Thrombosis Research Unit, Department of Clinical Medicine, Aalborg University, Aalborg, Denmark. Electronic address: g.y.h.lip@bham.ac.uk.
authors.forename: Gregory Yh
authors.initials: GY
authors.lastname: Lip
mesh_terms: D000368:Aged; D000925:Anticoagulants / Q000008:administration & dosage; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology*; D004311:Double-Blind Method; D005060:Europe / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006470:Hemorrhage / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology*; D006801:Humans; D007256:Information Systems; D008297:Male; D009656:North America / Q000453:epidemiology; D016032:Randomized Controlled Trials as Topic / Q000379:methods; D012307:Risk Factors; D020521:Stroke / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology*; D015996:Survival Rate / Q000639:trends; D013923:Thromboembolism / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology*; D014859:Warfarin / Q000008:administration & dosage
chemical_list: D000925:Anticoagulants; D014859:Warfarin
keywords: Atrial fibrillation; Bleeding risk; Geographical differences; Thromboembolic risk