CAC scoring improves CVD event prediction
MedWire News: Coronary artery calcium (CAC) scoring improves cardiovascular disease (CVD) event risk stratification in individuals with no history of such events, study findings show.
The results also indicate that the use of biomarkers, such as C-reactive protein (CRP) and interleukin (IL)-6, improves risk prediction, but does not improve risk classification, say the authors.
They explain: "CAC is a direct measurement of atherosclerosis and in this regard serves as a risk marker rather than a risk factor, as is the case for biomarkers."
The study involved 1286 CVD-free individuals with a mean age of 59 years. All were followed up for a mean period of 4.1 years during which CVD event rates were monitored.
As reported in the American Journal of Cardiology, 35 CVD events occurred over the follow-up period. Specifically, two (6%) CVD-related deaths, eight (23%) myocardial infarctions, six (17%) strokes, and 19 (54%) late coronary revascularizations occurred.
The accuracy of CVD-event risk estimation by various models was determined by c-statistic. Framingham Risk Score (FRS; based on age, smoking status, cholesterol, and blood pressure level) produced a c-statistic of 0.73.
This c-statistic increased to 0.84 when log CAC was added to the conventional FRS model. This inclusion of CAC produced a significant net improvement of 0.35 in risk stratification.
Individual and combined inclusion of five biomarkers (IL-6, CRP, myeloperoxidase, B-type natriuretic peptide, and plasminogen activator-1) into the FRS model did not improve the c-statistic obtained. But elevated levels of multiple biomarkers were found to double an individual's CVD-event risk.
Daniel Berman (Cedars-Sinai Medical Centre, Los Angeles, California, USA) and co-authors say: "Any new potential marker of disease should add significant predictive information beyond traditionally acquired information."
They conclude that the ability of CAC score to improve the predictive accuracy of FRS demonstrates its utility in performing prognostic assessments in CVD-free individuals.
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By Lauretta Ihonor