Breast arterial calcification on mammography and risk of coronary artery disease: a SCOT-HEART sub-study

To assess the prevalence of breast arterial calcification (BAC) in patients who also underwent routine surveillance mammography, and to determine the association with cardiovascular risk factors, coronary artery calcification, and coronary artery disease on coronary computed tomography angiography (CCTA).

Four hundred and five female participants were identified who had undergone CCTA and subsequent mammography in the SCOT-HEART randomised controlled trial of CCTA in patients with suspected stable angina. Mammograms were assessed visually for the presence and severity of BAC.

BAC was identified in 93 (23%) patients. Patients with BAC were slightly older (63±7 versus 59±8 years, p<0.001), with a higher cardiovascular risk score (19±11 versus 16±10, p=0.022) and were more likely to be non-smokers (73% versus 49%, p<0.001). In patients with BAC, coronary artery calcification was present in 58 patients (62%; relative risk [RR] 1.26, 95% confidence intervals [CI]: 1.04, 1.53; p=0.02), non-obstructive coronary artery disease in 58 (62%; RR 1.27, 95% CI: 1.04 to 1.54, p=0.02), and obstructive coronary artery disease in 19 (20%; RR 1.62, 95% CI: 0.98, 2.66; p=0.058). Patients without BAC were very unlikely to have severe coronary artery calcification (negative predictive value 95%) but the diagnostic accuracy of BAC to identify coronary artery disease was poor (AUC 0.547).

Although BAC is associated with the presence and severity of coronary artery calcification, the diagnostic accuracy to identify patients with coronary artery disease or obstructive coronary artery disease is poor.