Coronary artery calcium score and risk of coronary artery disease

January 01, 0001

Coronary artery calcium score and risk of coronary artery disease

The coronary artery calcium score (CACS) has been found to predict future coronary heart disease (CHD) events. These US researchers sought to determine whether adding CACS to a prediction model based on traditional risk factors improves classification of risk. CACS was measured by CT in participants of the Multi-Ethnic Study of Atherosclerosis (MESA), a population-based cohort(n=6814). Participants with diabetes were excluded. Five-year risk estimates for incident CHD events were categorized as 0% to less than 3%, 3% to less than 10%, and 10% or more using Cox proportional hazards models. Model 1 used age, sex, tobacco use, systolic blood pressure, antihypertensive medication use, total and high-density lipoprotein cholesterol, and race/ethnicity. Model 2 used these risk factors plus CACS.

The authors found: "During a median of 5.8 years of follow-up among a final cohort of 5878, 209 CHD events occurred, of which 122 were myocardial infarction, death from CHD, or resuscitated cardiac arrest. Model 2 resulted in significant improvements in risk prediction compared with model 1 (net reclassification improvement = 0.25). In model 1, 69% of the cohort was classified in the highest or lowest risk categories compared with 77% in model 2. An additional 23% of those who experienced events were reclassified as high risk, and an additional 13% without events were reclassified as low risk using model 2."

The authors concluded: "In this multi-ethnic cohort, addition of CACS to a prediction model based on traditional risk factors significantly improved the classification of risk and placed more individuals in the most extreme risk categories."

This study suggest that the addition of coronary artery calcium scoring to other risk factors improves risk stratification.

For the full abstract, click here.

JAMA 303(16):1610, 28 April 2010 © 2010 the American Medical Association
Coronary Artery Calcium Score and Risk Classification for Coronary Heart Disease Prediction. Tamar S. Polonsky, Robyn L. McClelland, Neal W. Jorgensen, et al.

Category: K. Circulatory. Keywords: coronary artery calcium scoring, risk factors, coronary artery disease, computerized tomography, risk stratification, cohort study, journal watch.
Synopsis edited by Dr Paul Schaefer, Toledo, Ohio. Posted on Global Family Doctor 1 June 2010

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