Longitudinal results of a prospective study of women with and without breast arterial calcifications showed that women with the calcifications were significantly more likely to have atherosclerotic cardiovascular events than were women without them.
In a 10-year follow-up of a cohort of women receiving screening mammograms, women who did not have cardiovascular disease at baseline and were positive for breast arterial calcifications (BACs) were three times more likely to develop atherosclerotic cardiovascular disease (ASCVD) as those who were BAC negative at baseline (9.8% vs. 3.3%; P = .001).
These results paralleled those found 5 years previously among the cohort. At that point, 6.3% of the BAC-positive group developed ASCVD, compared with 2.3% of the BAC-negative group (P = .003). At 10 years, “multiple logistic regression analysis found BAC to be strongly associated with ASCVD events, with an odds ratio of 2.29,” senior investigator Peter Schnatz, DO, said in an interview.
Based on these results, Dr. Schnatz and his coinvestigators are suggesting that BACs be routinely reported on mammograms and viewed as a marker for the development of cardiovascular disease.
Presenting the unpublished 10-year findings at the annual meeting of the North American Menopause Society, Dr. Schnatz, the society’s 2015-2016 president, said that the BAC-positive group was also more likely to develop risk factors for ASCVD (86.8% vs. 76.3; P = .01).
These risk factors were age, hypertension, hypercholesterolemia, diabetes, and menopause. The other results were significant after the investigators controlled for age, so the increased risk was not merely caused by the passage of time and the normal aging process.
The prospective study compared age-matched controls with and without BACs to determine whether BACs seen on routine mammography can predict the development of ASCVD, by tracking the presence of BACs and gathering information about ASCVD risk factors and events via patient self-report in an annual questionnaire. The events that were considered ASCVD markers were angina, myocardial infarction, an abnormal angiogram, coronary artery bypass grafting, and stroke.
The initial baseline study upon which the longitudinal prospective studies are based gathered data from 1,919 women with a median age of 56, plus or minus 12.7 years (range, 25-96), to determine whether women with BAC had an increased frequency of cardiovascular disease risk factors, and of ASCVD. Baseline findings showed an independent association of BAC with multiple risk factors and with ASCVD events, even after age was controlled for.
Dr. Schnatz, who is a professor of ob.gyn. and internal medicine at Thomas Jefferson University, Philadelphia, said in his presentation that BACs “appear to be a risk indicator of the presence of ASCVD. More importantly, in this first prospective analysis of BAC as a risk predictor, BAC appears to be a risk predictor for the future development of ASCVD.”
Patients were considered BAC positive if their mammograms showed BAC on at least one of two standard views of either or both breasts. The screening mammograms were read in a uniform fashion by 1 of 21 radiologists, who used identical and well-accepted criteria for BACs. Overall, 268 women (14%) were BAC positive, in line with the 9%-17.5% prevalence reported in the literature, Dr. Schnatz said.
BACs are diffuse calcifications of the arterial tunica media, which are common but often unreported by radiologists who find them on screening mammograms, though they are seen in up to 17.5% of mammograms.
Medial arterial calcifications, such as BACs, are fine-grained deposits seen in small- to medium-sized muscular arteries. Though they have been observed for some time, their significance has been unknown, and they are often seen as part of the normal aging process, Dr. Schnatz said. With the advent of newer mammography technology in the 2000s, much smaller calcifications could be seen, and research into the significance of BACs detected on screening mammogram was revived and refined, he said.
“If BAC has value as a marker for coronary artery disease, then mammograms could be a practical tool for detecting CAD risk in women,” Dr. Schnatz said. “This might contribute to earlier detection of vascular damage, especially important in women at high risk of CAD or with unrecognized heart disease.”
Dr. Schnatz said he plans to incorporate BAC status into validated cardiovascular risk predictors, and see how a prediction model that includes BAC fares.
Dr. Schnatz reported having no relevant financial disclosures.
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