Low breast density is associated with epicardial adipose tissue volume and coronary artery disease

Epicardial adipose tissue volume (EATv), is well correlated with coronary artery disease (CAD), however not reported clinically. Breast density, measured on mammography, has shown promise as a reflector of cardiometabolic risk, with less dense breasts indicating greater proportion of adipose tissue. We aimed to evaluate the association between breast density, EATv and CAD.

Retrospective, cross-sectional study including 153 women who had both clinically indicated coronary computed tomography angiogram (CCTA) and mammography. EATv was quantified using semi-automated software. Breast density was visually assessed by standard 4-level BI-RADS grading (low: BI-RADS A-B, high: BI-RADS CD). CAD was categorised as presence/absence of coronary artery plaque and severity was quantified using CAD-RADS score.

Among 153 patients (mean age 62 ± 10), 103 (67.3 %) had low breast density (high breast adiposity). Low breast density patients were older, had greater rates of hypertension, higher mean BMI (p < 0.001) and EATv (106.6 ± 43.0 ml vs 81.0 ± 31.6 ml, p < 0.001). EATv was predictive of low breast density (OR: 1.02[1.01-1.03], p = 0.006), independent of age and hypertension. Low breast density was strongly associated with presence of CAD (prevalence 75 % vs 48 %, OR: 3.21[1.58-6.53], p = 0.001) independent of EATv, and modifiable (OR: 2.69[1.24-5.92], p = 0.012) and non-modifiable (OR: 2.42[1.04-5.85], p = 0.047) cardiovascular risk factors. Low breast density made up a higher proportion of mild (76.5 %), moderate (73.9 %) and severe (80.0 %) CAD.

Low breast density is associated with higher EATv and independently associated with CAD presence beyond EATv and other cardiovascular risk factors. Mammographic breast density may therefore have value as an early risk identification tool for CAD in women.