Comparison of coronary artery calcium progression in African American and white men.
BACKGROUND
Although African Americans have a lower prevalence and extent of coronary artery calcium (CAC) than whites, the relationship between ethnicity and CAC progression is unknown. In a prospective rescan substudy of the Prospective Army Coronary Calcium (PACC) Project, we evaluated ethnic differences in the rates of CAC progression over 4 years.


METHODS
Two hundred healthy male PACC Project participants (age, 47.8 +/- 2.8 years) with CAC on their original scan volunteered to undergo a second electron beam tomography (EBT) scan and cardiovascular risk factor assessment (interscan interval, 4.3 +/- 1.2 y). All results were independently examined and blinded to baseline data. A change in CAC score >or=15%/y was defined as clinically significant progression. The relationship between race and CAC progression was evaluated with multivariable linear and logistic regression models controlling for age and other cardiovascular risk factors.


RESULTS
African Americans had significantly lower baseline CAC scores (34.3 vs 101.5; P = 0.004); lower follow-up CAC scores (56.6 vs 180.6; P = 0.001); and worse cardiovascular risk profiles. The annualized CAC progression rate was not significantly related to race in the multivariable linear regression model controlling for age, the Framingham risk score, and other cardiovascular risk factors. Significant CAC progression occurred in 43.5% of all participants. The incidence of significant progression of CAC for African American and white men was similar (53.1% vs 52.4%; P = 0.94), even when controlling for age, the Framingham risk score, and other cardiovascular risk factors.


CONCLUSIONS
Although African American men have less CAC than white men, CAC progression occurs at a comparable rate over 4 years.
Taylor
Allen J
AJ
Department of Medicine and Cardiology Service, Walter Reed Army Medical Center, Washington, DC, USA. allen.taylor@medstar.net
Wu
Holly
H
Bindeman
Jody
J
Bauer
Kelly
K
Byrd
Carole
C
O'Malley
Patrick G
PG
Feuerstein
Irwin
I
D001741:Black or African American / Q000706:statistics & numerical data; D002114:Calcinosis / Q000150:complications* / Q000000981:diagnostic imaging / Q000208:ethnology*; D002318:Cardiovascular Diseases / Q000208:ethnology* / Q000209:etiology*; D017023:Coronary Angiography / Q000379:methods; D003324:Coronary Artery Disease / Q000150:complications* / Q000000981:diagnostic imaging / Q000208:ethnology*; D018450:Disease Progression; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D008889:Military Personnel; D015995:Prevalence; D018570:Risk Assessment; D012307:Risk Factors; D014057:Tomography, X-Ray Computed; D014481:United States / Q000453:epidemiology; D044465:White People / Q000706:statistics & numerical data