title: Age dependence of risk factors for stroke and death in young patients with atrial fibrillation: a nationwide study.
abstract: OBJECTIVE
  The risk of stroke and death in patients with atrial fibrillation is strongly associated with age and concomitant comorbidities. The aim of this study was to examine the age dependence of risk factors for stroke and mortality in young patients with atrial fibrillation.
  
  
  METHODS
  This study is a population-based cohort study of 30- to 65-year-old patients with atrial fibrillation and diagnosed during 2000 to 2011, identified by record linkage between nationwide Danish registries. Cox regression models were used to estimate the risk of stroke and mortality according to risk factors within age groups: 30 to 50, 50 to 65, and 65 to 75 years.
  
  
  RESULTS
  We identified 73,799 nonvalvular atrial fibrillation patients, of which 37,782 (51.2%) were <65 years old (mean age 62.8). A higher modified cardiac failure or dysfunction, hypertension, age 75 (doubled), diabetes, stroke (doubled), vascular disease, age 65-74 and sex category (female) score (CHA2DS2-VASc score) was associated with decreased survival probability in all age groups. The overall incidence of stroke per year for 1 year (5 years) follow-up was 1.2% (0.6%), 3.5% (1.6%), and 5.6% (2.8%), respectively, for the age groups of 30 to 50, 50 to 65, and 65 to 75. Overall, risk factors such as previous stroke, heart failure, vascular disease, diabetes mellitus, and hypertension remained independent predictors of stroke and death in patients<65 years old with nonvalvular atrial fibrillation.
  
  
  CONCLUSIONS
  The CHA2DS2-VASc score is an applicable tool for all age groups and in nonvalvular atrial fibrillation patients<65 years old, the same risk factors apply.
authors.affiliation: From the Department of Cardiology, Atrial Fibrillation Study Group, Aalborg University Hospital, Aalborg, Denmark (L.M., F.S.T.B.L); Aalborg Thrombosis Research Unit, Department of Clinical Medicine, Faculty of Health, Aalborg University, Aalborg, Denmark (L.H.R., F.S., G.Y.H.L., T.B.L.); and University of Birmingham Centre for Cardiovascular Sciences, City Hospital, Birmingham, UK (G.Y.H.L.).
authors.forename: Line
authors.initials: L
authors.lastname: Melgaard
authors.forename: Lars Hvilsted
authors.initials: LH
authors.lastname: Rasmussen
authors.forename: Flemming
authors.initials: F
authors.lastname: Skjøth
authors.forename: Gregory Y H
authors.initials: GY
authors.lastname: Lip
authors.forename: Torben Bjerregaard
authors.initials: TB
authors.lastname: Larsen
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001281:Atrial Fibrillation / Q000150:complications / Q000453:epidemiology* / Q000401:mortality*; D003718:Denmark / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012042:Registries; D012307:Risk Factors; D012720:Severity of Illness Index; D012737:Sex Factors; D020521:Stroke / Q000453:epidemiology* / Q000209:etiology / Q000401:mortality
keywords: atrial fibrillation; death; risk factors; stroke