title: Echocardiographic measures of cardiac structure and function are associated with risk of atrial fibrillation in blacks: the Atherosclerosis Risk in Communities (ARIC) study.
abstract: BACKGROUND
  Several studies have examined the link between atrial fibrillation (AF) and various echocardiographic measures of cardiac structure and function in whites and other racial groups but not in blacks. Exploring AF risk factors in blacks is important given that the lower incidence of AF in this racial group despite higher risk factors, is not completely explained.
  
  
  METHODS
  We examined the association of echocardiographic measures with AF incidence in 2283 blacks (64.5% women, mean age 58.8 years) free of diagnosed AF and enrolled in the Jackson cohort of Atherosclerosis Risk in Communities (ARIC) study, a prospective study of cardiovascular disease. Echocardiography was performed in 1993-1995, and incident AF was determined by electrocardiograms at a follow-up study exam, hospitalization discharge codes and death certificates through the end of 2009. Cox proportional hazards regression was used to estimate hazard ratios and 95% confidence intervals for AF associated with the echocardiographic measures, adjusting for age, sex, and known AF risk factors.
  
  
  RESULTS
  During an average follow-up of 13.5 years, 191 (8.4%) individuals developed AF. Left ventricular (LV) internal diameter 2-D (diastole) and percent fractional shortening of LV diameter displayed a U-shaped relationship with risk of AF, while left atrial diameter displayed a J-shaped nonlinear association. LV mass index was associated positively with AF. E/A ratio <0.7 or >1.5 and ejection fraction (EF <50%) were also associated with higher AF risk. These measures improved risk stratification for AF in addition to traditional risk factors, although not significantly {C-statistic of 0.767 (0.714-0.819) vs. 0.744 (0.691-0.797)}.
  
  
  CONCLUSIONS
  In a community-based population of blacks, echocardiographic measures of cardiac structure and function are significantly associated with an increased risk of AF.
authors.affiliation: Cardiovascular Division, University of Minnesota, Minneapolis, Minnesota, United States of America.
authors.forename: Wobo
authors.initials: W
authors.lastname: Bekwelem
authors.affiliation: Division of Epidemiology and Community Health, University of Minnesota, Minneapolis, Minnesota, United States of America.
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Misialek
authors.affiliation: Cardiovascular Division, University of Minnesota, Minneapolis, Minnesota, United States of America.
authors.forename: Suma
authors.initials: S
authors.lastname: Konety
authors.affiliation: Department of Noninvasive Cardiology, Brigham and Women's Hospital, Boston, Massachusetts, United States of America.
authors.forename: Scott D
authors.initials: SD
authors.lastname: Solomon
authors.affiliation: Epicare, Wake Forest University School of Medicine, Winston-Salem, North Carolina, United States of America.
authors.forename: Elsayed Z
authors.initials: EZ
authors.lastname: Soliman
authors.affiliation: Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America.
authors.forename: Laura R
authors.initials: LR
authors.lastname: Loehr
authors.affiliation: Division of Epidemiology and Community Health, University of Minnesota, Minneapolis, Minnesota, United States of America.
authors.forename: Faye L
authors.initials: FL
authors.lastname: Lopez
authors.affiliation: Division of Cardiology, University of Mississippi, Jackson, Mississippi, United States of America.
authors.forename: Ervin R
authors.initials: ER
authors.lastname: Fox
authors.affiliation: Division of Geriatrics, University of Mississippi, Jackson, Mississippi, United States of America.
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Mosley
authors.affiliation: Division of Epidemiology and Community Health, University of Minnesota, Minneapolis, Minnesota, United States of America.
authors.forename: Alvaro
authors.initials: A
authors.lastname: Alonso
mesh_terms: D000368:Aged; D050197:Atherosclerosis / Q000453:epidemiology*; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging* / Q000208:ethnology* / Q000473:pathology / Q000503:physiopathology; D044383:Black People / Q000706:statistics & numerical data*; D004452:Echocardiography; D005260:Female; D006321:Heart / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D012111:Residence Characteristics / Q000706:statistics & numerical data*; D012307:Risk Factors