Coronary Artery Calcium Scoring: Ready for Routine Use?
CAC improved predictive accuracy when added to traditional risk factors.
Coronary artery calcium (CAC) scores as assessed by computed tomography correlate with burden of atherosclerosis and risk for future adverse coronary events. In this analysis, U.S. investigators examined a cohort of 5878 ethnically diverse patients without known atherosclerosis or diabetes to assess whether CAC scoring at baseline, added to traditional risk factors, allowed reclassification of patients into higher- or lower-risk groups for subsequent adverse cardiac events.
Of 209 events that occurred during 6 years of follow-up, 122 were death, myocardial infarction, or resuscitated cardiac arrest. Patients were categorized as low (5-year risk, 0%–<3%), intermediate (3%–10%), and high (>10%) risk for incident adverse cardiac events by demographics and traditional risk factors (i.e., tobacco use, systolic blood pressure, antihypertensive use, and total and HDL cholesterol levels). When CAC scoring was added to this model, risk prediction improved significantly; more patients were categorized to low- or high-risk groups (77% with CAC vs. 69% without CAC), and fewer patients were in the intermediate-risk category.
Comment: In this analysis, CAC scores added value to standard risk factors in the prediction of subsequent events. Editorialists emphasize that CAC score is a promising predictor but that routine use cannot be recommended until its effect on outcomes, as well as risks and costs, is evaluated. Moreover, several promising novel risk factors, such as high-sensitivity C-reactive protein and carotid intima-media thickness, are under investigation and should be considered alongside CAC score as possible predictors.
Published in Journal Watch General Medicine May 4, 2010
Polonsky TS et al. Coronary artery calcium score and risk classification for coronary heart disease prediction. JAMA 2010 Apr 28; 303:1610. [Medline® Abstract]
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