Ethnic differences in the prognostic value of coronary artery calcification for all-cause mortality.
OBJECTIVE
The purpose of this study was to evaluate the prognostic value of coronary artery calcium (CAC), a known marker of subclinical atherosclerosis, in a large, ethnically diverse cohort of 14,812 patients for the prediction of all-cause mortality.


BACKGROUND
Disparities in case fatality rates for heart disease among ethnic groups are well known. In 2001, rates of death from heart disease were 30% higher among African Americans (AA) than non-Hispanic whites (NHW). Some of this variability may be due to differing pathophysiological mechanisms and effects of underlying atherosclerosis.


METHODS
Ten-year death rates from all causes (total deaths = 505) were compared using risk-adjusted Cox proportional hazards models in AA (n = 637), Hispanic (HS, n = 1,334), Asian (AS, n = 1,065), and NHW (n = 11,776) populations.


RESULTS
Ethnic minority patients were generally younger (0.3 to 4 years), more often persons with diabetes (p < 0.0001), hypertensive (p < 0.0001), and female (p < 0.0001). The prevalence of CAC scores > or =100 was highest in NHW (31%) and lowest for HS (18%) (p < 0.0001). Overall survival was 96%, 93%, and 92% for AS, NHW, and HS, respectively, as compared with 83% for AA (p < 0.0001). When comparing prognosis by CAC scores in ethnic minorities as compared with NHW, relative risk ratios were highest for AA with CAC scores > or =400 exceeding 16.1 (p < 0.0001). Hispanics with CAC scores > or =400 had relative risk ratios from 7.9 to 9.0, whereas AS with CAC scores > or =1,000 had relative risk ratios 6.6-fold higher than NHW (p < 0.0001).


CONCLUSIONS
Consistent with population evidence, AA with increasing burden of subclinical coronary artery disease were the highest-risk ethnic minority population. These data support a growing body of evidence noting substantial differences in cardiovascular risk by ethnicity.
Nasir
Khurram
K
Cardiac MRI PET CT Program, Massachusetts General Hospital Boston, Harvard School of Medicine, Boston, Massachusetts, USA.
Shaw
Leslee J
LJ
Liu
Sandy T
ST
Weinstein
Steven R
SR
Mosler
Tristen R
TR
Flores
Phillip R
PR
Flores
Ferdinand R
FR
Raggi
Paolo
P
Berman
Daniel S
DS
Blumenthal
Roger S
RS
Budoff
Matthew J
MJ
D001741:Black or African American / Q000706:statistics & numerical data; D000368:Aged; D001213:Asian / Q000706:statistics & numerical data; D002114:Calcinosis; D003327:Coronary Disease / Q000000981:diagnostic imaging / Q000208:ethnology* / Q000401:mortality; D003331:Coronary Vessels / Q000737:chemistry* / Q000473:pathology; D005260:Female; D006630:Hispanic or Latino / Q000706:statistics & numerical data; D006801:Humans; D008017:Life Expectancy; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011379:Prognosis; D016016:Proportional Hazards Models; D012307:Risk Factors; D016019:Survival Analysis; D014057:Tomography, X-Ray Computed; D014481:United States / Q000453:epidemiology; D044465:White People / Q000706:statistics & numerical data