title: Atrial fibrillation in Indigenous and non-Indigenous Australians: a cross-sectional study.
abstract: OBJECTIVE
  To examine the prevalence of atrial fibrillation (AF) and cardiac structural characteristics in Indigenous and non-Indigenous Australians.
  
  
  METHODS
  Retrospective cross-sectional study linking clinical, echocardiography and administrative databases over a 10-year period.
  
  
  METHODS
  A tertiary, university teaching hospital in Adelaide, Australia.
  
  
  METHODS
  Indigenous and non-Indigenous Australians.
  
  
  METHODS
  AF prevalence and echocardiographic characteristics.
  
  
  RESULTS
  Indigenous Australians with AF were significantly younger compared to non-Indigenous Australians (55±13 vs 75±13 years, p<0.001). As a result, racial differences in AF prevalence and left atrial diameter varied according to age. In those under 60 years of age, Indigenous Australians had a significantly greater AF prevalence (2.57 vs1.73%, p<0.001) and left atrial diameters (39±7 vs 37±7 mm, p<0.001) compared to non-Indigenous Australians. In those aged 60 years and above, however, non-Indigenous Australians had significantly greater AF prevalence (9.26 vs 4.61%, p<0.001) and left atrial diameters (39±7 vs 37±7 mm, p<0.001). Left ventricular ejection fractions were less in Indigenous Australians under 60 years of age (49±14 vs 55±11%, p<0.001) and not statistically different in those aged 60 years and above (47±11 vs 52±13, p=0.074) compared to non-Indigenous Australians. Despite their younger age, Indigenous Australians with AF had similar or greater rates of cardiovascular comorbidities than non-Indigenous Australians with AF.
  
  
  CONCLUSIONS
  Young Indigenous Australians have a significantly greater prevalence of AF than their non-Indigenous counterparts. In contrast, older non-Indigenous Australians have a greater prevalence of AF compared to their Indigenous counterparts. These observations may be mediated by age-based differences in comorbid cardiovascular conditions, left atrial diameter and left ventricular ejection fraction. Our findings suggest that AF is likely to be contributing to the greater burden of morbidity and mortality experienced by young Indigenous Australians. Further study is required to elucidate whether strategies to prevent and better manage AF in Indigenous Australians may reduce this burden.
authors.affiliation: Centre for Heart Rhythm Disorders (CHRD), South Australian Health and Medical Research Institute (SAHMRI), University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia.
authors.forename: Christopher X
authors.initials: CX
authors.lastname: Wong
authors.affiliation: Centre for Heart Rhythm Disorders (CHRD), South Australian Health and Medical Research Institute (SAHMRI), University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia.
authors.forename: Anthony G
authors.initials: AG
authors.lastname: Brooks
authors.affiliation: Centre for Heart Rhythm Disorders (CHRD), South Australian Health and Medical Research Institute (SAHMRI), University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia.
authors.forename: Yi-Han
authors.initials: YH
authors.lastname: Cheng
authors.affiliation: Centre for Heart Rhythm Disorders (CHRD), South Australian Health and Medical Research Institute (SAHMRI), University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia.
authors.forename: Dennis H
authors.initials: DH
authors.lastname: Lau
authors.affiliation: Centre for Heart Rhythm Disorders (CHRD), South Australian Health and Medical Research Institute (SAHMRI), University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia.
authors.forename: Geetanjali
authors.initials: G
authors.lastname: Rangnekar
authors.affiliation: Centre for Heart Rhythm Disorders (CHRD), South Australian Health and Medical Research Institute (SAHMRI), University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia.
authors.forename: Kurt C
authors.initials: KC
authors.lastname: Roberts-Thomson
authors.affiliation: Department of Cardiology, Royal Melbourne Hospital, Melbourne, Australia.|Department of Medicine, University of Melbourne, Melbourne, Australia.
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Kalman
authors.affiliation: Aborginal Health Research, South Australian Health and Medical Research Institute (SAHMRI) and School of Population Health, University of South Australia, Adelaide, Australia.
authors.forename: Alex
authors.initials: A
authors.lastname: Brown
authors.affiliation: Centre for Heart Rhythm Disorders (CHRD), South Australian Health and Medical Research Institute (SAHMRI), University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia.
authors.forename: Prashanthan
authors.initials: P
authors.lastname: Sanders
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000208:ethnology*; D001315:Australia / Q000453:epidemiology; D015897:Comorbidity; D003430:Cross-Sectional Studies; D004452:Echocardiography; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging; D006801:Humans; D006973:Hypertension / Q000453:epidemiology / Q000208:ethnology; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000453:epidemiology / Q000208:ethnology; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors; D044465:White People / Q000706:statistics & numerical data*