“Calcium build-up within the middle layer of the breast’s arterial wall, known as breast arterial calcification (BAC), is commonly seen on mammograms,” explains Carlos Iribarren, MD, MPH, PhD. “There is increasing evidence, however, that BAC correlates with angiographically-defined cardiovascular artery disease and indicates increased risk for cardiovascular disease (CVD) outcomes. This is particularly important given that CVD, including coronary heart disease, is one of the two leading causes of death among women in the United States.”

For a paper published in Circulation: Cardiovascular Imaging, Dr. Iribarren and colleagues sought to clarify the potential role of BAC evaluation on primary prevention CVD risk stratification. The researchers recruited and examined more than 5,000 women aged 60-79 who had a screening mammogram at one of nine Kaiser Permanente Northern California hospitals between October 24, 2012, and February 13, 2015. The women had no prior history of CVD or breast cancer.

Women With BAC 51% More Likely to Experience Heart Disease, Stroke

After a mean follow-up period of 6.5 years, the researchers reported 155 atherosclerotic CVD (ASCVD) events (3.0%) and 427 global CVD events (8.4%). All age-adjusted rates per 1,000 person-years were consistently higher for women with BAC than those without BAC, and statistically significant for ischemic stroke, CVD death, hard ASCVD, cerebrovascular disease, cardiomyopathy, peripheral arterial disease, deep venous thrombosis/pulmonary embolism, retinal vascular occlusion, and global CVD (Table).

BAC greater than 0 mg was reported in 26.5% of participants. Individuals with BAC were older, more likely to be White or Hispanic, less likely to be Black or Asian, and less likely to have pursued graduate studies or a professional degree. Women with BAC had non-clinically significant higher HDL-C, a higher prevalence of prediabetes and diabetes, higher systolic blood pressure, and higher prevalence of hypertension.

“We found that women who had BAC present on their mammogram were 51% more likely to develop heart disease or have a stroke compared with women who did not have BAC,” Dr. Iribarren says. “Women with BAC were also 23% more likely to develop any type of CVD, including heart disease, stroke, heart failure, and diseases of the peripheral arteries.”

Dr. Iribarren and colleagues point out that the wide availability and acceptance of routine mammograms could present a unique opportunity for clinicians to extend the conversation with patients about cancer screening to include heart health. “Physicians may be able to leverage this opportunity to discuss ways to optimize heart health, such as engaging in regular physical activity, adhering to a healthy diet, avoiding smoking and maintaining a healthy weight,” he says.

Plan to Investigate BAC as a Predictor in Younger Women

This study has moved the needle in favor of reporting BAC and incorporating it into risk stratification, the study team notes. “We are continuing to conduct research in this area,” Dr. Iribarren says. “However, we will most likely need to see a clinical trial demonstrate that BAC reporting does improve risk factor profile and compliance with treatments before we see BAC reporting and integration into risk stratification become routine.”

This research is part of the MultIethNic Study of BrEast ARterial Calcium Gradation and CardioVAscular Disease, or, study launched by the researchers in 2010. Previous MINERVA analyses showed BAC was associated with the ankle brachial index (a measure of peripheral arterial disease), but not with mild cognitive impairment or dementia or bone mineral density.

“Going forward, we plan to investigate whether BAC is also helpful in predicting CVD among younger women, aged 40 through 59,” he says.