Incidence of atrial fibrillation in whites and African-Americans: the Atherosclerosis Risk in Communities (ARIC) study.
OBJECTIVE
To define the incidence and cumulative risk of atrial fibrillation (AF) in a population-based cohort of whites and African Americans.


BACKGROUND
African-Americans reportedly have a lower risk of AF than whites despite their higher exposure to AF risk factors. However, precise estimates of AF incidence in African Americans have not been previously published.


METHODS
We studied the incidence of AF in the Atherosclerosis Risk in Communities (ARIC) study, which has followed up 15,792 men and women 45 to 65 years of age at baseline from 4 communities in the United States since 1987. Atrial fibrillation cases were identified from electrocardiograms conducted at baseline and 3 follow-up visits, and from hospitalizations and death certificates through the end of 2004. During follow-up, 1,085 new cases of AF were identified (196 in African Americans, 889 in whites).


RESULTS
Crude incidence rates of AF were 6.7, 4.0, 3.9, and 3.0 per 1,000 persons per year in white men, white women, African-American men, and African-American women, respectively. Increasing age was exponentially associated with an elevated risk of AF. Compared to whites, African-Americans had a 41% (95% CI: 8%-62%) lower age- and sex-adjusted risk of being diagnosed with AF. The cumulative risk of AF at 80 years of age was 21% in white men, 17% in white women, and 11% in African-American men and women.


CONCLUSIONS
In this population-based cohort, African Americans presented a lower risk of AF than whites. Still, the burden of AF among the former is substantial, with 1 in 9 receiving a diagnosis of AF before 80 years of age.
Alonso
Alvaro
A
Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, 1300 S 2nd Street, Minneapolis, MN 55454. USA. aalogut@alumni.unav.es
Agarwal
Sunil K
SK
Soliman
Elsayed Z
EZ
Ambrose
Marietta
M
Chamberlain
Alanna M
AM
Prineas
Ronald J
RJ
Folsom
Aaron R
AR
D001741:Black or African American / Q000706:statistics & numerical data*; D050197:Atherosclerosis / Q000453:epidemiology* / Q000208:ethnology*; D001281:Atrial Fibrillation / Q000453:epidemiology* / Q000208:ethnology*; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D011446:Prospective Studies; D018570:Risk Assessment; D012815:Signal Processing, Computer-Assisted; D014481:United States; D044465:White People / Q000706:statistics & numerical data*