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Circulation. 2018 Oct 23;138(17):1819-1827. doi: 10.1161/CIRCULATIONAHA.118.033505.

Astronaut Cardiovascular Health and Risk Modification (Astro-CHARM) Coronary Calcium Atherosclerotic Cardiovascular Disease Risk Calculator.

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Department of Internal Medicine (A.K., J.A.d.L., B.D.L.), at the University of Texas Southwestern Medical Center, Dallas, TX.
Division of Cardiology (A.K., J.A.d.L., B.D.L.), at the University of Texas Southwestern Medical Center, Dallas, TX.
Division of Cardiology, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, CA (M.J.B.).
The National Heart, Lung, and Blood Institute's the Framingham Heart Study, Framingham, Massachusetts; Cardiology Section, Department of Medicine, Boston Veteran's Administration Healthcare (C.J.O.).
Department of Clinical Sciences (C.A.A.) at the University of Texas Southwestern Medical Center, Dallas, TX.
National Aeronautics and Space Agency, Johnson Space Center, Houston, TX (J.L.).
Department of Mathematics, Boston University, MA (J.M.M.).
Department of Biostatistics, University of Washington, Seattle (R.L.M.).
Divison of Cardiology, Georgetown University; and MedStar Georgetown University Hospital and MedStar Health Research Institute, Washington, DC (A.T.).
Institute for Exercise and Environmental Medicine, Presbyterian Hospital, Dallas, TX (B.D.L.).



Coronary artery calcium (CAC) is a powerful novel risk indicator for atherosclerotic cardiovascular disease (ASCVD). Currently, there is no available ASCVD risk prediction tool that integrates traditional risk factors and CAC.


To develop a CAC ASCVD risk tool for younger individuals in the general population, subjects aged 40 to 65 without prior cardiovascular disease from 3 population-based cohorts were included. Cox proportional hazards models were developed incorporating age, sex, systolic blood pressure, total and high-density lipoprotein cholesterol, smoking, diabetes mellitus, hypertension treatment, family history of myocardial infarction, high-sensitivity C-reactive protein, and CAC scores (Astro-CHARM model [Astronaut Cardiovascular Health and Risk Modification]) as dependent variables and ASCVD (nonfatal/fatal myocardial infarction or stroke) as the outcome. Model performance was assessed internally, and validated externally in a fourth cohort.


The derivation study comprised 7382 individuals with a mean age 51 years, 45% women, and 55% nonwhite. The median CAC was 0 (25th, 75th [0,9]), and 304 ASCVD events occurred in a median 10.9 years of follow-up. The c-statistic was 0.784 for the risk factor model, and 0.817 for Astro-CHARM ( P<0.0001). In comparison with the risk factor model, the Astro-CHARM model resulted in integrated discrimination improvement (0.0252), and net reclassification improvement (0.121; P<0.0001), as well. The Astro-CHARM model demonstrated good discrimination (c=0.78) and calibration (Nam-D'Agostino χ2, 13.2; P=0.16) in the validation cohort (n=2057; 55 events). A mobile application and web-based tool were developed to facilitate clinical application of this tool ( ).


The Astro-CHARM tool is the first integrated ASCVD risk calculator to incorporate risk factors, including high-sensitivity C-reactive protein and family history, and CAC data. It improves risk prediction in comparison with traditional risk factor equations and could be useful in risk-based decision making for cardiovascular disease prevention in the middle-aged general population.


calcification of joints and arteries; coronary vessels; risk assessment

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