RACIAL-DIFFERENCES IN CORONARY CALCIUM PREVALENCE AMONG HIGH-RISK ADULTS

A total of 1,461 asymptomatic high-risk adult subjects were studied wi th digital subtraction fluoroscopy and conventional cinefluoroscopy to detect coronary calcium, Ethnicity and risk factor data were recorded . No subject had a history or electrocardiographic evidence of prior m yocardial infarction. The prevalence of coronary calcium by digital su btraction fluoroscopy (58%). Substantial ethnic differences in prevale nce were noted: 36% of African American subjects, 60% of Caucasian sub jects and 60% of Asian American subjects had definite radiographic evi dence of coronary calcium. The difference in prevalence between Africa n American and other subjects was significant (p<0.0001) by chi-square test for all 3 races. These differences persisted in the unsubtracted cinefluoroscopic images (p <0.0001) and after controlling for age, ge nder, and other risk factors (p = 0.003). After 20 +/- 11 months of fo llow-up, African Americans had more coronary artery disease events (13 %) than Caucasians (6%) or Asian Americans (5%) (p = 0.04). Thus, Afri can Americans have a significantly lower prevalence of coronary calciu m than do Caucasians or Asian Americans. Based on the follow-vp result s, these differences in prevalence are not explained by differences in coronary artery disease risk.