By Nick Klenske
Research shows how mammography can be used not only for breast cancer screening, but also to evaluate a woman’s risk for cardiovascular disease.
Breast cancer is a major cause of death for women, but it isn’t the leading cause. That distinction goes to heart disease. In fact, in the United States, heart disease kills five times more women than breast cancer every year.
But that doesn’t mean the two diseases don’t cross paths.
According to Matthew Nudy, MD, a cardiologist at Penn State, and Alyssa (Lisa) Watanabe, MD, a radiologist at the University of Southern California Keck School of Medicine in Los Angeles, the path to assessing heart disease risk could be improved with breast cancer screening.
“Breast arterial calcification (BAC), as seen on mammography, is an important—albeit underreported—risk marker for cardiovascular disease,” said Dr. Nudy during a Wednesday session.
Drs. Nudy and Watanabe recently co-authored a study that evaluated whether women who have higher severity of BAC, or who have progression of BAC on sequential mammograms, are at an elevated risk for a major adverse cardiovascular event (MACE).
“Measuring BAC progression on sequential mammograms may be a useful predictive tool for identifying women at the highest risk for heart disease and stroke.”
Alyssa (Lisa) Watanabe, MD
The study evaluated over 40,000 mammograms in over 20,000 women, with imaging follow-up ranging from six months to 10 years and clinical follow-up between six months and 15 years.
An AI-based model was then used to generate a quantitative BAC case score for each four-view mammogram. Women with BAC were assigned to quartiles based on how severe the calcium was for their age. BAC positive scores were age-adjusted to derive percentiles: 1st-25th (Q1),26-50th (Q2), 51-75th (Q3) and 76-100th (Q4).
BAC severity scores and progression rates in BAC positive women were compared to MACE outcomes. Women who were BAC negative were used as a reference control group.
Higher but stable BAC quartiles were associated with high hazard ratios (HRs). HRs were 1.41 for Q2, 1.28 for Q3, and 2.11 for Q4. In those showing BAC progression, the hazard ratios rose to 2.19 for Q1→Q3, 8.66 for Q1→Q4, and 1.90 for Q3→Q4. These effects were even more pronounced in women under 65, with HRs of 2.80 (Q1→Q3), 10.86 (Q1→Q4), and 2.01 (Q3→Q4).
Based on this work, the researchers concluded that the presence of BAC on a mammogram is associated with a significantly higher risk for MACE. They further found that BAC severity, when normalized for age, is a marker of a further increase in risk.
“A major conclusion of our study is that women who have progression of BAC on sequential mammograms are at an elevated risk of developing cardiovascular disease compared to women with stable or no BAC,” Dr. Nudy explained.
“Measuring BAC progression on sequential mammograms may be a useful predictive tool for identifying women at the highest risk for heart disease and stroke,” Dr. Watanabe added.
Having shown that mammography can be used to screen for both breast cancer and heart disease risk, the study’s authors recommend that BAC presence be reported on screening mammograms.
“Reporting BAC provides an opportunity to identify at-risk patients earlier, implement guideline-based preventive strategies and hopefully, reduce long-term cardiovascular risk,” Dr. Watanabe said.
While BAC reporting and grading is recommended by the Canadian Society of Breast Imaging (SBI), the SBI and the European Society of Breast Imaging have not yet issued position statements. The BIRADS 5th edition currently describes BAC reporting as optional.
“Mammography has the potential to identify subclinical cardiovascular disease in women aside from breast cancer screening alone and this may be an important opportunity to improve risk assessment of cardiovascular disease in women,” Dr. Nudy concluded.
Access the presentation, “Breast Arterial Calcification Progression on Mammograms Predicts Risk of Major Adverse Cardiovascular Events,” (W3-SSCA07-2) on demand at RSNA.org/MeetingCentral.
