title: Brachial flow-mediated dilation and incident atrial fibrillation: the multi-ethnic study of atherosclerosis.
abstract: OBJECTIVE
  It is unknown whether endothelial dysfunction precedes atrial fibrillation (AF) development. The objective of this study was to examine the association of brachial flow-mediated dilation (FMD) with incident AF.
  
  
  RESULTS
  A total of 2936 participants (mean age, 61±9.9 years; 50% women; 66% nonwhites) from the Multi-Ethnic Study of Atherosclerosis with available ultrasound brachial FMD measurements who were free of baseline AF were included in this analysis. Baseline (2000-2002) FMD was computed from the percentage difference (%FMD) in brachial artery diameter and maximum diameter during measured vasodilator response. AF was ascertained from hospitalization data including Medicare claims during a median follow-up of 8.5 years. Probability-weighted Cox proportional-hazards regression was used to compute hazard ratios and 95% confidence intervals for the association between FMD as a continuous variable (%FMD values per 1-SD increase) and incident AF. Incident AF was detected in 137 (4.7%) participants. Those with %FMD values below the sex-specific median value (median %FMD; men, 3.6%; women, 4.2%; incidence rate per 1000 person-years, 7.3; 95% confidence interval, 5.9-9.0) were more likely to develop AF than people whose %FMD values were above the median value (incidence rate per 1000 person-years, 4.5; 95% confidence interval, 3.4-5.8; log-rank P=0.0043). In a multivariable Cox regression analysis, each 1-SD increase in %FMD values (SD, 2.8%) was associated with less incident AF (hazard ratio, 0.84; 95% confidence interval, 0.70-0.99). These results were consistent across subgroups stratified by age, sex, and race/ethnicity.
  
  
  CONCLUSIONS
  Smaller brachial FMD values are associated with higher rates of AF, suggesting a role for endothelial dysfunction in AF pathogenesis.
authors.affiliation: From the Department of Internal Medicine (W.T.O.), Department of Internal Medicine, Section on Cardiology (J.Y., E.Z.S.), and Department of Epidemiology and Prevention, Epidemiological Cardiology Research Center (EPICARE) (E.Z.S.), Wake Forest School of Medicine, Winston-Salem, NC; Department of Cardiovascular Sciences, East Carolina Heart Institute, Brody School of Medicine, East Carolina University, Greenville, NC (J.T.E.); Departments of Medicine and Cardiology, Johns Hopkins University School of Medicine, Baltimore, MD (S.N.); Department of Epidemiology and Community Health, School of Public Health, University of Minnesota, Minneapolis (A.A.); and Cardiovascular Health Research Unit, Department of Epidemiology, University of Washington, Group Health Research Institute, Seattle (S.R.H.). woneal@wakehealth.edu.
authors.forename: Wesley T
authors.initials: WT
authors.lastname: O'Neal
authors.affiliation: From the Department of Internal Medicine (W.T.O.), Department of Internal Medicine, Section on Cardiology (J.Y., E.Z.S.), and Department of Epidemiology and Prevention, Epidemiological Cardiology Research Center (EPICARE) (E.Z.S.), Wake Forest School of Medicine, Winston-Salem, NC; Department of Cardiovascular Sciences, East Carolina Heart Institute, Brody School of Medicine, East Carolina University, Greenville, NC (J.T.E.); Departments of Medicine and Cardiology, Johns Hopkins University School of Medicine, Baltimore, MD (S.N.); Department of Epidemiology and Community Health, School of Public Health, University of Minnesota, Minneapolis (A.A.); and Cardiovascular Health Research Unit, Department of Epidemiology, University of Washington, Group Health Research Institute, Seattle (S.R.H.).
authors.forename: Jimmy T
authors.initials: JT
authors.lastname: Efird
authors.affiliation: From the Department of Internal Medicine (W.T.O.), Department of Internal Medicine, Section on Cardiology (J.Y., E.Z.S.), and Department of Epidemiology and Prevention, Epidemiological Cardiology Research Center (EPICARE) (E.Z.S.), Wake Forest School of Medicine, Winston-Salem, NC; Department of Cardiovascular Sciences, East Carolina Heart Institute, Brody School of Medicine, East Carolina University, Greenville, NC (J.T.E.); Departments of Medicine and Cardiology, Johns Hopkins University School of Medicine, Baltimore, MD (S.N.); Department of Epidemiology and Community Health, School of Public Health, University of Minnesota, Minneapolis (A.A.); and Cardiovascular Health Research Unit, Department of Epidemiology, University of Washington, Group Health Research Institute, Seattle (S.R.H.).
authors.forename: Joseph
authors.initials: J
authors.lastname: Yeboah
authors.affiliation: From the Department of Internal Medicine (W.T.O.), Department of Internal Medicine, Section on Cardiology (J.Y., E.Z.S.), and Department of Epidemiology and Prevention, Epidemiological Cardiology Research Center (EPICARE) (E.Z.S.), Wake Forest School of Medicine, Winston-Salem, NC; Department of Cardiovascular Sciences, East Carolina Heart Institute, Brody School of Medicine, East Carolina University, Greenville, NC (J.T.E.); Departments of Medicine and Cardiology, Johns Hopkins University School of Medicine, Baltimore, MD (S.N.); Department of Epidemiology and Community Health, School of Public Health, University of Minnesota, Minneapolis (A.A.); and Cardiovascular Health Research Unit, Department of Epidemiology, University of Washington, Group Health Research Institute, Seattle (S.R.H.).
authors.forename: Saman
authors.initials: S
authors.lastname: Nazarian
authors.affiliation: From the Department of Internal Medicine (W.T.O.), Department of Internal Medicine, Section on Cardiology (J.Y., E.Z.S.), and Department of Epidemiology and Prevention, Epidemiological Cardiology Research Center (EPICARE) (E.Z.S.), Wake Forest School of Medicine, Winston-Salem, NC; Department of Cardiovascular Sciences, East Carolina Heart Institute, Brody School of Medicine, East Carolina University, Greenville, NC (J.T.E.); Departments of Medicine and Cardiology, Johns Hopkins University School of Medicine, Baltimore, MD (S.N.); Department of Epidemiology and Community Health, School of Public Health, University of Minnesota, Minneapolis (A.A.); and Cardiovascular Health Research Unit, Department of Epidemiology, University of Washington, Group Health Research Institute, Seattle (S.R.H.).
authors.forename: Alvaro
authors.initials: A
authors.lastname: Alonso
authors.affiliation: From the Department of Internal Medicine (W.T.O.), Department of Internal Medicine, Section on Cardiology (J.Y., E.Z.S.), and Department of Epidemiology and Prevention, Epidemiological Cardiology Research Center (EPICARE) (E.Z.S.), Wake Forest School of Medicine, Winston-Salem, NC; Department of Cardiovascular Sciences, East Carolina Heart Institute, Brody School of Medicine, East Carolina University, Greenville, NC (J.T.E.); Departments of Medicine and Cardiology, Johns Hopkins University School of Medicine, Baltimore, MD (S.N.); Department of Epidemiology and Community Health, School of Public Health, University of Minnesota, Minneapolis (A.A.); and Cardiovascular Health Research Unit, Department of Epidemiology, University of Washington, Group Health Research Institute, Seattle (S.R.H.).
authors.forename: Susan R
authors.initials: SR
authors.lastname: Heckbert
authors.affiliation: From the Department of Internal Medicine (W.T.O.), Department of Internal Medicine, Section on Cardiology (J.Y., E.Z.S.), and Department of Epidemiology and Prevention, Epidemiological Cardiology Research Center (EPICARE) (E.Z.S.), Wake Forest School of Medicine, Winston-Salem, NC; Department of Cardiovascular Sciences, East Carolina Heart Institute, Brody School of Medicine, East Carolina University, Greenville, NC (J.T.E.); Departments of Medicine and Cardiology, Johns Hopkins University School of Medicine, Baltimore, MD (S.N.); Department of Epidemiology and Community Health, School of Public Health, University of Minnesota, Minneapolis (A.A.); and Cardiovascular Health Research Unit, Department of Epidemiology, University of Washington, Group Health Research Institute, Seattle (S.R.H.).
authors.forename: Elsayed Z
authors.initials: EZ
authors.lastname: Soliman
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D050197:Atherosclerosis / Q000209:etiology / Q000503:physiopathology; D001281:Atrial Fibrillation / Q000209:etiology* / Q000503:physiopathology*; D001783:Blood Flow Velocity; D001916:Brachial Artery / Q000000981:diagnostic imaging / Q000503:physiopathology*; D015331:Cohort Studies; D004730:Endothelium, Vascular / Q000503:physiopathology; D005006:Ethnicity; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D014463:Ultrasonography; D014664:Vasodilation / Q000502:physiology*
keywords: atrial fibrillation; endothelium; epidemiology