Breast Arterial Calcification May Increase Risk of ASCVD

New research published in Circulation: Cardiovascular Imaging suggests that breast arterial calcification (BAC), a common incidental finding in mammography, has potential utility for primary cardiovascular disease (CVD) prevention and could be considered a risk-enhancing factor for atherosclerotic CVD (ASCVD) among postmenopausal women.

Cancer and CVD—including coronary heart disease—are the top 2 causes of death among American women, authors explained, and despite recommendations, “attendance to screening mammography is 68% among women 50 and older and 71% among women 50 to 64 and in managed care is 88.4% overall.”

Although BAC is currently not considered a clinically actionable finding on mammography and is not included in CVD primary prevention guidelines, past evidence has indicated it may be associated with angiographically defined coronary artery disease. “BAC represents medial calcium deposits leading to vascular stiffness and is related more closely to diabetes and hypertension,” authors explained.

To better understand the potential relationship between BAC and CVD risk, researchers assessed data from the Multiethnic Study of Breast Arterial Calcium Gradation and Cardiovascular Disease (MINERVA).

All participants were between the ages of 60 and 79 years when they underwent regular mammography screenings at Kaiser Permanente facilities between October 2012 and February 2015.

Any individual with a history of myocardial infarction, coronary revascularization, stroke, heart failure, and other potentially confounding conditions were excluded from the final cohort.

Screenings from 5059 women were ultimately assessed for BAC status (presence vs absence) and quantity (calcium mass mg). Of these, 26.5% had a BAC greater than 0 mg, while after a mean (SD) follow-up of 6.5 (1.6) years, 155 individuals (3%) had an ASCVD event and 427 (8.4%) had global CVD events.

Incident ASCVD was defined as acute myocardial infarction, ischemic stroke or CVD death; composite of global CVD was ascertained based on incidence of ischemic heart disease, cerebrovascular disease, heart failure, cardiomyopathy, deep vein thrombosis/pulmonary embolism, cardiac arrest, peripheral arterial disease, retinal vascular occlusion, or CVD death.

Analyses adjusted for traditional CVD risk factors revealed:

• BAC presence was associated with a 1.51 (95% CI, 1.08-2.11; P = .02) increased hazard of ASCVD and a 1.23 (95% CI, 1.002-1.52; P = .04) increased hazard of global CVD.
• While there was no evidence of dose-response association with ASCVD, a threshold effect was found for global CVD at very high BAC burden (95th percentile when BAC present).
• BAC status provided additional risk stratification of the pooled cohorts equations risk.

“We noted improvements in model calibration and reclassification of ASCVD: the overall net reclassification improvement was 0.12 (95% CI, 0.03-0.14; P = .01) and the bias-corrected clinical-net reclassification improvement was 0.11 (95% CI, 0.01-0.22; P = .04) after adding BAC status,” authors noted.

Women with BAC were more likely to be White or Hispanic; had a higher prevalence of diabetes, prediabetes, and hypertension; and had higher systolic blood pressure.

Contrary to previous studies, the researchers did not find an association between smoking and BAC in this cohort.

Findings also imply “women with BAC at borderline or intermediate ASCVD risk may be candidates for more aggressive treatment, and women with BAC already at high risk may be candidates for intensification of therapy,” researchers wrote.

Results may not be generalizable to younger women or those without insurance and investigators were unable to assess the importance of localized vs diffuse BAC in the current analysis.

“Further research in large cohorts with longer follow-up period is needed to better delineate the dose-response association between BAC burden and CVD outcomes and to establish the value of BAC in women before age 60,” they concluded.

Reference

Iribarren C, Chandra M, Lee C, et al. Breast arterial calcification: a novel cardiovascular risk enhancer among postmenopausal women. Circ Cardiovasc Imaging. Published online March 15, 2022. doi:10.1161/CIRCIMAGING.121.013526