Distribution of coronary artery calcium scores by Framingham 10-year risk strata in the MESA (Multi-Ethnic Study of Atherosclerosis) potential implications for coronary risk assessment.
J Am Coll Cardiol 2011;
57:1838-45. [PMID:
21527159 DOI:
10.1016/j.jacc.2010.11.053]
[Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2010] [Revised: 10/18/2010] [Accepted: 11/01/2010] [Indexed: 11/20/2022]
Abstract
OBJECTIVES
By examining the distribution of coronary artery calcium (CAC) levels across Framingham risk score (FRS) strata in a large, multiethnic, community-based sample of men and women, we sought to determine if lower-risk persons could benefit from CAC screening.
BACKGROUND
The 10-year FRS and CAC levels are predictors of coronary heart disease. A CAC level of 300 or more is associated with the highest risk for coronary heart disease even in low-risk persons (FRS, <10%); however, expert groups have suggested CAC screening only in intermediate-risk groups (FRS, 10% to 20%).
METHODS
We included 5,660 Multi-Ethnic Study of Atherosclerosis participants. The number needed to screen (number of people that need to be screened to detect 1 person with CAC level above the specified cutoff point) was used to assess the yield of screening for CAC. CAC prevalence was compared across FRS strata using chi-square tests.
RESULTS
CAC levels of more than 0, of 100 or more, and of 300 or more were present in 46.4%, 20.6%, and 10.1% of participants, respectively. The prevalence and amount of CAC increased with higher FRS. A CAC level of 300 or more was observed in 1.7% and 4.4% of those with FRS of 0% to 2.5% and of 2.6% to 5%, respectively (number needed to screen, 59.7 and 22.7, respectively). Likewise, a CAC level of 300 or more was observed in 24% and 30% of those with FRS of 15.1% to 20% and more than 20%, respectively (number needed to screen, 4.2 and 3.3, respectively). Trends were similar when stratified by age, sex, and race or ethnicity.
CONCLUSIONS
Our study suggests that in very low-risk individuals (FRS ≤5%), the yield of screening and probability of identifying persons with clinically significant levels of CAC is low, but becomes greater in low- and intermediate-risk persons (FRS 5.1% to 20%).
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