Author + information
- Received October 3, 2011
- Revision received January 2, 2012
- Accepted January 20, 2012
- Published online September 1, 2012.
- Tochi M. Okwuosa, DO⁎,
- Philip Greenland, MD†,
- Hongyan Ning, MD, MS†,
- Kiang Liu, PhD† and
- Donald M. Lloyd-Jones, MD, ScM†,⁎ ()
- ↵⁎Reprint requests and correspondence:
Dr. Donald M. Lloyd-Jones, Department of Preventive Medicine and Bluhm Cardiovascular Institute, Northwestern University, 680 North Lake Shore Drive, Suite 1400, Chicago, Illinois 60611
Objectives The purpose of this study was to assess the prevalence and distribution of coronary artery calcium (CAC) across Framingham Risk Score (FRS) strata and therefore determine FRS levels at which asymptomatic, young to early middle-age individuals could potentially benefit from CAC screening.
Background High CAC burden is associated with increased risk of coronary events beyond the FRS. Expert panel recommendations for CAC screening are based on data obtained in middle-age and older individuals.
Methods We included 2,831 CARDIA (Coronary Artery Risk Development in Young Adults) study participants with an age range of 33 to 45 years. The number needed to screen ([NNS] number of people in each FRS stratum who need to be screened to detect 1 person with a CAC score above the specified cut point) was used to assess the yield of screening for CAC. CAC prevalence was compared across FRS strata using a chi-square test.
Results CAC scores >0 and ≥100 were present in 9.9% and 1.8% of participants, respectively. CAC prevalence and amount increased across higher FRS strata. A CAC score >0 was observed in 7.3%, 20.2%, 19.1%, and 44.8% of individuals with FRSs of 0 to 2.5%, 2.6% to 5%, 5.1% to 10%, and >10%, respectively (NNS = 14, 5, 5, and 2, respectively). A CAC score of ≥100 was observed in 1.3%, 2.4%, and 3.5% of those with FRSs of 0 to 2.5%, 2.6% to 5%, and 5.1% to 10%, respectively (NNS = 79, 41, and 29, respectively), but in 17.2% of those with an FRS >10% (NNS = 6). Similar trends were observed when findings were stratified by sex and race.
Conclusions In this young to early middle-age cohort, we observed concordance between CAC prevalence/amount and FRS strata. Within this group, the yield of screening and possibility of identifying those with a high CAC burden (CAC score of ≥100) is low in those with an FRS of ≤10%, but considerable in those with an FRS >10%.
- coronary artery calcium
- coronary heart disease
- Framingham Risk Score
- number needed to screen
- risk factors
Work was supported (or partially supported) by contracts from University of Alabama at Birmingham, Coordinating Center, N01-HC-95095; University of Alabama at Birmingham, Field Center, N01-HC-48047; University of Minnesota, Field Center and Diet Reading Center (Year 20 Exam), N01-HC-48048; Northwestern University, Field Center, N01-HC-48049; Kaiser Foundation Research Institute, N01-HC-48050; University of California, Irvine, Echocardiography Reading Center (Year 5 & 10), N01-HC-45134; Harbor-UCLA Research Education Institute, Computed Tomography Reading Center (Year 15 Exam), N01-HC-05187; Wake Forest University (Year 20 Exam), N01-HC-45205; New England Medical Center (Year 20 Exam), N01-HC-45204 from the National Heart, Lung, and Blood Institute. All authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- Received October 3, 2011.
- Revision received January 2, 2012.
- Accepted January 20, 2012.
- American College of Cardiology Foundation