title: Individual and Combined Risk Factors for Incident Atrial Fibrillation and Incident Stroke: An Analysis of 3 Million At-Risk US Patients.
abstract: BACKGROUND
  The incremental effects of risk factor combinations for atrial fibrillation (AF) and stroke are incompletely understood. We sought to quantify the risks of incident AF and stroke for combinations of established risk factors in a large US sample.
  
  
  RESULTS
  Patients with no evidence of AF or stroke in 2007 were stratified by combinations of the following risk factors: heart failure, hypertension, diabetes, age 65 to 74, age ≥75, coronary artery disease, and chronic kidney disease. Patients with ≥2 of the first 5 or ≥3 of the first 7, classified as "high-risk," and an age-matched sample of patients with fewer risk factors, classified as "low-risk," were followed over 2008-2010 for incident AF and stroke. Annualized incidence rates and risks were quantified for each combination of factors by using Cox regression. Annualized incidence rates for AF, stroke, and both were 3.59%, 3.27%, and 0.62% in 1 851 653 high-risk patients and 1.32%, 1.48%, and 0.18% in 1 156 221 low-risk patients, respectively. Among patients with 1 risk factor, those with age ≥75 had the highest hazards of incident AF and stroke (HR 9.2, 6.9). Among patients with 2 risk factors, those with age ≥75 and heart failure had the highest annualized incidence rates of AF and stroke (10.2%, 5.9%). The combination of age ≥75 and hypertension was prevalent and had the highest incidences of AF and stroke.
  
  
  CONCLUSIONS
  Adults with combinations of known risk factors are at increased risk of incident AF and stroke, but combinations of risk factors are not always additive.
authors.affiliation: Columbia University Medical Center, New York, NY (J.Y.C.).
authors.forename: Janice Y
authors.initials: JY
authors.lastname: Chyou
authors.affiliation: CTI Clinical Trial and Consulting Services, Cincinnati, OH (T.D.H.).
authors.forename: Tina D
authors.initials: TD
authors.lastname: Hunter
authors.affiliation: Medtronic, plc, Mounds View, MN (S.A.M.).
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Mollenkopf
authors.affiliation: Stanford University School of Medicine, Palo Alto, CA (M.P.T.).
authors.forename: Mintu P
authors.initials: MP
authors.lastname: Turakhia
authors.affiliation: Harvard Clinical Research Institute, Boston, MA (M.R.R.) Lahey Hospital and Medical Center, Burlington, MA (M.R.R.).
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Reynolds
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D015897:Comorbidity; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D020521:Stroke / Q000175:diagnosis / Q000453:epidemiology*; D013997:Time Factors; D014481:United States / Q000453:epidemiology; D055815:Young Adult
keywords: atrial fibrillation; epidemiology; risk factors/global assessment; risk stratification; stroke