This article is more than 5 years old. Information may no longer be current.
Routine mammography could be useful for CV risk assessment in women
CHICAGO — The assessment of breast arterial calcification on digital mammography may be a useful strategy to screen for coronary artery calcification in women, researchers reported at the American College of Cardiology Scientific Session.
“Many women fear breast cancer much more than they fear CVD. [Digital] mammography is a commonly performed screening exam [for breast cancer], but we don’t routinely screen for CVD, although it kills [10 times] more women than breast cancer,” Laurie Margolies, MD, associate professor of radiology at Icahn School of Medicine at Mount Sinai, said during an ACC briefing.
Laurie Margolies
Margolies and fellow investigators aimed to present a “practical, accessible way of assessing a woman’s risk for CVD.” Breast arterial calcification (BAC) includes the number of vessels, length of involvement and density of calcification. “BAC is easily evaluable on every mammogram at no additional cost and radiation, but is not reported,” she said.
Quantitative association
The researchers compared BAC with coronary artery calcification (CAC) in 292 asymptomatic women, including 33 with known CAD, who underwent digital mammography and non-gated CT within 1 year. Both BAC and CAC were evaluated using scores of 0 to 12. A second radiologist blinded to the CAC results reviewed the mammograms. BAC was evaluated on a scale from 0 to 12 by increasing severity and CAC was measured on CT using a validated severity score of 0 to 12.
BAC was observed in 42.5% of women. It was associated with older age (P < .0001), chronic kidney disease (P < .0001) and hypertension (P = .0007). CAC was found in 47.6% of women.
The overall mean BAC score was 2.2 and mean CAC score was 1.6. The frequency of BAC > 0 was 27% for women aged 39 to 59 years, 47% for women aged 60 to 69 years and 69% for women aged 70 to 92 years (P < .0001). The frequency of CAC > 0 increased from 28% to 55% to 79%, respectively, among the age groups (P < .0001).
All BAC variables predicted CAC score (P < .0001). In multivariable analysis, the OR for CAC > 0 was 3.2 for BAC score 4 to 12; 2 for age; and 2.2 for hypertension.
The sensitivity, specificity, positive predictive value, negative predictive value and overall accuracy of BAC > 0 for CAC > 0 was 63%, 76%, 70%, 69% and 70%, according to Margolies. The researchers also observed fewer false positives among younger patients.
The researchers also compared BAC to the Framingham Risk Score and the 2013 Cholesterol Guidelines Pooled Cohort Equations. BAC appeared to be as strong a predictor for CV risk as the Framingham Risk Score and the Pooled Cohort Equations. When the researchers added 33 asymptomatic women with established CAD, BAC was more powerful than both risk-assessment formulas, according to a press release.
“This study is the first to demonstrate the strong quantitative association of BAC by digital mammography with CAC in a large female cohort, its superiority to individual standard CV risk factors and its equivalence to the risk factor-based paradigms for the identification of women with CAC, with borderline additive value to the Pooled Cohort Equations,” the researchers wrote in JACC: Cardiovascular Imaging.
Potentially practice-changing
Margolies said this study is “potentially practice-changing in how radiologists read and report mammograms. … BAC-positive women should undergo further risk assessment, preferably with a gated CAC scan, with subsequent adjustment or institution of statins as indicated by the CAC score.”
The researchers noted that the predictive power of BAC should be evaluated in a large, prospective, outcomes-based trial. Future prospective trials are needed to determine what the prognostic significance of BAC might be. Because the study involved women who received both mammography and CT scan for clinical indications, these women may have been more likely than the average woman to have coexisting conditions, although Harvey Hecht, MD, professor at the Icahn School of Medicine at Mount Sinai and director of cardiovascular imaging at Mount Sinai St. Luke’s Hospital, said in the release that these were unrelated to heart disease.
“The message is if a woman is getting a mammogram, look for [BAC]. It's a freebie and provides critical information that could be lifesaving for some women,” Hecht said in the release. “The more [BAC] a woman has, the more likely she is to have calcium in her heart’s arteries as well. If all it requires is to take a closer look at the images, how can we ignore it?,” he said. – by Katie Kalvaitis
Reference:
Hecht HS, et al. Poster 1184-256. Non Invasive Imaging: Non Contrast CT. Presented at: American College of Cardiology Scientific Session; April 2-4, 2016; Chicago.
Margolies L, et al. JACC Cardiovasc Imaging. 2016;doi:10.1016/j.jcmg.2015.10.022.
Disclosure: This study was supported in part by the Flight Attendants Medical Research Institute. Hecht reports consulting for Philips Medical Systems. Margolies reports no relevant financial disclosures.
Perspective
Back to Top
CAC screening has been a powerful tool at assessing CV risk, especially in higher-risk patients. This study is important, because it extends the possibilities that arterial calcification in general, may predict outcomes. Importantly though, this study used a protocol of mammography, with expert radiology interpretation— all of these things are important. The finding that this type of arterial calcification represents a risk is very interesting. But we don’t yet know what to do with patients with this type of arterial calcification. One would assume they should be referred to a cardiologist for further risk assessment of diabetes, hypertension, hyperlipidemia, etc. Does this study suggest that mammography is a 'twofer?' Is a woman of any age going to be able to be screened for vascular disease at the same time as she is screened for breast cancer? This is potentially very exciting, but [the excitement] has to be tempered. The message could go out that all you need to do is get a mammogram and you’ll know if you have heart disease. That is a very bad message. What I will tell patients asking me about this study is that you can’t just go back and ask a radiologist to look at your last mammogram to assess your risk of CVD. This type of mammography is not ready for prime time for all breast-imaging centers to be able to identify this type of calcification, because there will be a learning curve for radiologists. Larger studies with broader outcomes need to be performed. And there is a need for team-based care with radiologists, primary care physicians and CV specialists working together to assess risks and advise women as to the best course of action.