title: Atrial fibrillation and the risk of myocardial infarction.
abstract: OBJECTIVE
  Myocardial infarction (MI) is an established risk factor for atrial fibrillation (AF). However, the extent to which AF is a risk factor for MI has not been investigated.
  
  
  OBJECTIVE
  To examine the risk of incident MI associated with AF.
  
  
  METHODS
  A prospective cohort of 23,928 participants residing in the continental United States and without coronary heart disease at baseline were enrolled from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) cohort between 2003 and 2007, with follow-up through December 2009.
  
  
  METHODS
  Expert-adjudicated total MI events (fatal and nonfatal).
  
  
  RESULTS
  Over 6.9 years of follow-up (median 4.5 years), 648 incident MI events occurred. In a sociodemographic-adjusted model, AF was associated with about 2-fold increased risk of MI (hazard ratio [HR], 1.96 [95% CI, 1.52-2.52]). This association remained significant (HR, 1.70 [95% CI, 1.26-2.30]) after further adjustment for total cholesterol, high-density lipoprotein cholesterol, smoking status, systolic blood pressure, blood pressure-lowering drugs, body mass index, diabetes, warfarin use, aspirin use, statin use, history of stroke and vascular disease, estimated glomerular filtration rate, albumin to creatinine ratio, and C-reactive protein level. In subgroup analysis, the risk of MI associated with AF was significantly higher in women (HR, 2.16 [95% CI, 1.41-3.31]) than in men (HR, 1.39 [95% CI, 0.91-2.10]) and in blacks (HR, 2.53 [95% CI, 1.67-3.86]) than in whites (HR, 1.26 [95% CI, 0.83-1.93]); for interactions, P = .03 and P = .02, respectively. On the other hand, there were no significant differences in the risk of MI associated with AF in older (≥75 years) vs younger (<75 years) participants (HR, 2.00 [95% CI, 1.16-3.35] and HR, 1.60 [95% CI, 1.11-2.30], respectively); for interaction, P = .44.
  
  
  CONCLUSIONS
  AF is independently associated with an increased risk of incident MI, especially in women and blacks. These findings add to the growing concerns of the seriousness of AF as a public health burden: in addition to being a well-known risk factor for stroke, AF is also associated with increased risk of MI.
authors.affiliation: Epidemiological Cardiology Research Center, Department of Epidemiology and Prevention, Wake Forest School of Medicine, Winston Salem, North Carolina2Section on Cardiology, Department of Internal Medicine, Wake Forest School of Medicine, Winston Salem, Nor.
authors.forename: Elsayed Z
authors.initials: EZ
authors.lastname: Soliman
authors.affiliation: Division of Preventive Medicine, University of Alabama at Birmingham.
authors.forename: Monika M
authors.initials: MM
authors.lastname: Safford
authors.affiliation: Department of Epidemiology, University of Alabama at Birmingham.
authors.forename: Paul
authors.initials: P
authors.lastname: Muntner
authors.affiliation: Division of Preventive Medicine, University of Alabama at Birmingham.
authors.forename: Yulia
authors.initials: Y
authors.lastname: Khodneva
authors.affiliation: Section on Cardiology, Department of Internal Medicine, Wake Forest School of Medicine, Winston Salem, North Carolina.
authors.forename: Farah Z
authors.initials: FZ
authors.lastname: Dawood
authors.affiliation: Department of Medicine, University of Vermont, Burlington.
authors.forename: Neil A
authors.initials: NA
authors.lastname: Zakai
authors.affiliation: Department of Epidemiology, University of Alabama at Birmingham.
authors.forename: Evan L
authors.initials: EL
authors.lastname: Thacker
authors.affiliation: Department of Biostatistics, University of Alabama at Birmingham.
authors.forename: Suzanne
authors.initials: S
authors.lastname: Judd
authors.affiliation: Department of Epidemiology, University of Alabama at Birmingham.
authors.forename: Virginia J
authors.initials: VJ
authors.lastname: Howard
authors.affiliation: Department of Biostatistics, University of Alabama at Birmingham.
authors.forename: George
authors.initials: G
authors.lastname: Howard
authors.affiliation: Section on Cardiology, Department of Internal Medicine, Wake Forest School of Medicine, Winston Salem, North Carolina.
authors.forename: David M
authors.initials: DM
authors.lastname: Herrington
authors.affiliation: Department of Medicine, University of Vermont, Burlington.
authors.forename: Mary
authors.initials: M
authors.lastname: Cushman
mesh_terms: D001741:Black or African American / Q000706:statistics & numerical data; D000368:Aged; D001281:Atrial Fibrillation / Q000453:epidemiology* / Q000208:ethnology; D015331:Cohort Studies; D003920:Diabetes Mellitus / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000453:epidemiology* / Q000208:ethnology; D016016:Proportional Hazards Models; D011446:Prospective Studies; D051436:Renal Insufficiency, Chronic / Q000453:epidemiology; D012307:Risk Factors; D012737:Sex Factors; D014481:United States / Q000453:epidemiology; D044465:White People / Q000706:statistics & numerical data