Coronary artery calcium scanning: Clinical paradigms for cardiac risk assessment and treatment
Received 3 May 2005; accepted 12 July 2005.
Background
Coronary artery calcium (CAC) scanning is being increasingly used for cardiac risk assessment in asymptomatic patients, particularly in those with a Framingham 10-year risk of 10% to 20%. Physician awareness of this technology and its appropriate uses and limitations is crucial to appropriate use.
Methods
With the goal of establishing clinical paradigms, this document integrates the results of key published articles, Framingham Risk Score, National Cholesterol Education Program Adult Treatment Plan III guidelines, American College of Cardiology/American Heart Association exercise testing and angiographic guidelines, and the authors' extensive clinical experience.
Results
Coronary artery calcium scanning is best used in the asymptomatic population with a 10% to 20% risk of cardiac events over 10 years, with selected application in higher and lower risk categories. In the 10%-20% risk patient, coronary artery calcium scores >100 or >75th percentile for age and sex transform the moderately high-risk patient to higher risk status with the attendant recommendation for more aggressive therapy; scores from 11 to 100 and <75th percentile are consistent with the 10%-20% 10-year risk status and scores from 0 to 10 and <75th percentile convert the patient to lesser risk categories. If stress testing is planned in the asymptomatic patient, it should be preceded by coronary artery calcium scanning and performed only for scores >400; it should always precede coronary angiography in these patients.
Conclusions
Coronary artery calcium scanning is an important risk assessment tool with direct clinical applications; it is of particular utility in the Framingham 10%-20% 10-year risk population.
aLenox Hill Heart and Vascular Institute, New York, NY
bHarbor-UCLA Research and Education Institute, Harbor-UCLA Medical Center, Torrance, CA
cDepartment of Imaging, Cedars-Sinai Medical Center, Los Angeles, CA
dDepartment of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA
eThe Burns and Allen Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA
fGeorge Washington University School of Medicine, Washington, DC
gOhio State University School of Medicine, Columbus, OH
Reprint requests: Harvey S. Hecht, MD, FACC, Lenox Hill Heart and Vascular Institute, 130 E. 77th St., New York, NY 10021.
ABSTRACT