Ethnic Differences in Coronary Calcification

TLDR

Coronary calcification, a marker of coronary atherosclerosis, is known to be higher in US whites than blacks, yet large population‑based comparisons across US ethnic groups have been lacking. The study aimed to uncover the mechanisms behind these ethnic disparities and to evaluate the predictive value of coronary calcium across different ethnic groups. Using computed tomography, the authors measured coronary calcification in 6,814 participants of diverse ethnicities (white, black, Hispanic, Chinese) aged 45–84 years from the Multi‑Ethnic Study of Atherosclerosis. They found that whites had the highest prevalence and burden of calcification, with blacks, Hispanics, and Chinese showing significantly lower relative risks (0.78, 0.85, 0.92) and lower amounts (69–77% of whites), differences that persisted after adjusting for traditional risk factors.

Abstract

There is substantial evidence that coronary calcification, a marker for the presence and quantity of coronary atherosclerosis, is higher in US whites than blacks; however, there have been no large population-based studies comparing coronary calcification among US ethnic groups.Using computed tomography, we measured coronary calcification in 6814 white, black, Hispanic, and Chinese men and women aged 45 to 84 years with no clinical cardiovascular disease who participated in the Multi-Ethnic Study of Atherosclerosis (MESA). The prevalence of coronary calcification (Agatston score >0) in these 4 ethnic groups was 70.4%, 52.1%, 56.5%, and 59.2%, respectively, in men (P<0.001) and 44.6%, 36.5%, 34.9%, and 41.9%, respectively, (P<0.001) in women. After adjustment for age, education, lipids, body mass index, smoking, diabetes, hypertension, treatment for hypercholesterolemia, gender, and scanning center, compared with whites, the relative risks for having coronary calcification were 0.78 (95% CI 0.74 to 0.82) in blacks, 0.85 (95% CI 0.79 to 0.91) in Hispanics, and 0.92 (95% CI 0.85 to 0.99) in Chinese. After similar adjustments, the amount of coronary calcification among those with an Agatston score >0 was greatest among whites, followed by Chinese (77% that of whites; 95% CI 62% to 96%), Hispanics (74%; 95% CI 61% to 90%), and blacks (69%; 95% CI 59% to 80%).We observed ethnic differences in the presence and quantity of coronary calcification that were not explained by coronary risk factors. Identification of the mechanism underlying these differences would further our understanding of the pathophysiology of coronary calcification and its clinical significance. Data on the predictive value of coronary calcium in different ethnic groups are needed.