Could mammograms detect clogged arteries as well as breast cancer? Yes, says new research

A woman’s routine mammogram is a bulwark against dying of breast cancer, which strikes 1 in 8 women over a lifetime. But new research suggests that, with little extra cost or effort, a woman’s mammogram could also tell whether she is being stalked by a far more dangerous killer of women - coronary heart disease.

Heart disease kills about 1 in 4 women, and coronary heart disease - a buildup of plaque in the arteries leading to the heart - is its most common form. But giving a woman warning that she may have dangerous plaque buildup there might be as easy as asking the radiologist who reads her mammograms what he or she sees in the blood vessels that are clearly visible inside the breast.

Physicians meeting this week at an American College of Cardiology scientific session in Chicago are expected to hear about a simple way to wring more lifesaving out of the 37 million mammograms performed every year in the United States. It was published last week in the Journal of the American College of Cardiology’s JACC: Cardiovascular Imaging.

It turns out that radiologists checking breast images for abnormal masses have always been able to see plaque in the arteries that bring oxygenated blood to the breasts. The question was, was it meaningful? How often do calcifications in those arteries indicate the presence of calcifications in the coronary arteries, which can impede blood flow to the heart and break lose, causing heart attacks?

Today, a woman with no symptoms of clogged arteries, including chest pain and shortness of breath, generally relies on one of two risk calculators to guide decisions such as whether she should take a statin or other medication aimed at reducing her heart attack risk. Toting up her age, family medical history, smoking and weight status, blood pressure and cholesterol profile, her physician can calculate her Framingham Risk Score. Many of the same measures are also used in the 2013 Cholesterol Guidelines Pooled Cohort Equations.

But could the information already on a mammogram predict just as well whether a woman should take specific steps to avert a heart attack?

Radiologists and cardiologists at Mount Sinai in New York City devised a “breast arterialization score” for 325 women who had had, within the same year, both a digital mammogram and a CT scan of their chest. The CT scan would show definitively whether the woman had coronary artery calcification, or CAC. So the study’s aim was to determine just how closely correlated plaque buildup in the breast arteries are to CAC.

None of the women had symptoms of coronary artery disease. Most, however, were at increased heart disease risk by virtue of their having been referred to get a CT scan to screen for lung cancer or pulmonary disorder. The CT scans showed that almost 48% had signs of plaque buildup in their coronary arteries.

In those women who had coronary artery calcification as shown by CT scan, the breast arterialization score predicted it 63% of the time. Using BAC to predict coronary artery calcification gave a false positive 24% of the time. As a predictor of a woman’s coronary arterial calcification, a woman’s breast arterial calcification, or BAC, score was superior to the Framingham Risk Score and superior to the 2013 cholesterol guidelines, the study found.

The BAC score was best at predicting coronary artery calcification in women older than 70. But even in women 39 to 59, its authors suggested the BAC score uncovered about half of women at higher risk for heart disease - and at an age when they probably would not have been flagged by other measures.

Dr. Larry Altshuler, director of oncology intake at Cancer Treatment Centers of America, said the findings could be a “game-changer” when it comes to women’s health.

“Many women, especially younger women, are unaware of their heart health,” Altshuler said. With earlier warning that plaque could be accumulating in their coronary arteries, more women could take control of their health and take action to prevent heart attacks or strokes, he added.

The authors concluded that looking at the blood vessels in a women’s mammogram for indications of heart disease risk is promising, and should be studied in a larger trial.

Even so, wrote Drs. Khurram Nasir and John W. McEvoy in an accompanying editorial in JACC, it’s not premature to suggest that radiologists who detect breast arterial calcification make note of those findings in reporting to a woman’s primary care physician. They wrote that, guided by further research, experts will need to determine whether women with elevated BAC scores should be put on statin drugs or referred for CT scans to confirm suspicions.

Plumbing mammograms for more detailed information about a woman’s health is not entirely new. Radiologists were long able to detect breast density in certain women by reading their mammograms, but did not until recently report it.

But while breast density may affect a woman’s risk for breast cancer, looking for evidence of heart disease in a mammogram has the potential to prevent many more women’s deaths.

Women are more than seven times likelier to die of heart disease than of breast cancer in any given year. But because breast cancer campaigns have had such a high profile, women tend to be more scared of getting breast cancer than they are of developing heart disease.

While experts in recent years have squabbled over how young women should start getting mammograms and how often they need them, fear of breast cancer has made screening a regular occurrence for most women. If those mammograms could offer early warning of blocked arteries, lots of women might be saved.

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