Impact of coronary calcium on arterial age and coronary heart disease risk estimation using the MESA arterial age calculator.

BACKGROUND: We evaluated the impact of arterial age calculation on reclassification of global coronary heart disease risk using the Framingham risk score. METHODS: We applied CHD risk factor data from the Prospective Army Coronary Calcium Project to the MESA arterial age calculator (available at http://www.mesa-nhlbi.org). Subjects (N=1998) were studied with measured CHD risk factors and electron beam computed tomography for the identification of coronary artery calcium. Framingham risk scores (FRS), using the 10-year CHD risk model with and without arterial age, were calculated using the MESA arterial age calculator. RESULTS: The mean FRS of the cohort (42.9 + or - 2.7 years, male gender 82%) was 4.5 + or - 3.6%. Coronary calcium was present in 394 subjects (19.7%). Application of the arterial age calculator increased mean age from 42.9 + or - 2.7 to 43.6 + or - 10.4 years (P<.001), and the mean FRS increased from 4.5 + or - 3.6 to 7.3 + or - 8.1% (P<.001). Reclassification was seen primarily among male subjects, in whom the mean age (chronological vs. arterial age) increased from 42.9 + or - 2.7 to 44.2 + or - 11.0 (P<.001) and the prevalence of high CHD risk increased from 0.6% (10 of 1639) to 10% (165 of 1639; P<.001). CONCLUSION: Among healthy individuals ages 40-50, application of the MESA arterial age calculator reclassifies 1 in 10 men from low to intermediate risk and 1 in 15 men from low to high risk.