OBJECTIVES This study sought to determine whether evaluations of breast arterial calcification (BAC) and low bone mass (LBM) could improve the ability to predict subclinical coronary artery disease (CAD) in asymptomatic women.

BACKGROUND An improved risk stratification strategy beyond the measurement of conventional risk factors is needed to identify women at high risk of CAD.

METHODS The BBC (Women Health Registry Study for Bone, Breast, and Coronary Artery Disease) enrolled 2,100 asymptomatic women who underwent dual-energy X-ray absorptiometry, digital mammography, and coronary computed tomography angiography. We assessed the predicted 10-year atherosclerotic cardiovascular disease (ASCVD) risk and evaluated the presence and severity of BAC, LBM, coronary artery calcification (CAC), and coronary atherosclerotic plaque (CAP).

RESULTS CAC and CAP were found in 11.2% and 15.6% of participants, respectively. In women with CAC or CAP, increasing trends in the presence and severity of both BAC and LBM were observed. Both BAC and LBM were found to be associated with the presence of CAC (unadjusted odds ratios [OR]: 3.54 and 2.22, respectively) and CAP (unadjusted OR: 3.02 and 1.91, respectively). However, in multivariate analysis, only the presence of BAC and BAC score remained as independent predictors. For the prediction of CAC and CAP, addition of the BAC presence to the 10-year ASCVD risk significantly increased the areas under the curve (area under the curve: 0.71 to 0.72; p = 0.016; and area under the curve: 0.66 to 0.68; p = 0.010; respectively) and resulted in net reclassification index improvements (area under the curve: 0.304; p <0.001; and area under the curve: 0.245; p <0.001; respectively).

CONCLUSIONS The presence and severity of BAC and LBM were significantly associated with the risk of subclinical CAD in asymptomatic women. BAC evaluation especially provides an independent and incremental value over conventional risk algorithms. (Women Health Cohort for Breast, Bone and Coronary Artery Disease [BBC]; NCT03235622).