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 May 3;57(18):1838-45. doi: 10.1016/j.jacc.2010.11.053.


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%).

Publication types

  • Multicenter Study

MeSH terms

  • Age Factors
  • Aged
  • Aged, 80 and over
  • Calcinosis / diagnostic imaging
  • Calcinosis / epidemiology*
  • Coronary Angiography
  • Coronary Artery Disease / diagnostic imaging
  • Coronary Artery Disease / epidemiology*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Multivariate Analysis
  • Prevalence
  • Prospective Studies
  • Racial Groups
  • Risk Assessment
  • Sex Factors
  • Tomography, X-Ray Computed
  • United States / epidemiology