Research led by Harvard Medical School shows the level of plaque clogging a person’s arteries is likely more relevant for judging heart attack risk in men than in women.
The study, published in Circulation: Cardiovascular Imaging, showed that while women have significantly lower levels of coronary artery plaque than men, this does not necessarily translate to lower risk for cardiovascular disease and events such as heart attacks.
Heart disease is the main cause of death for both men and women in the U.S., but it is becoming increasingly clear that symptoms and risks for this major killer are not the same in men and women. For example, men often experience heart attack or other cardiovascular events at an earlier age whereas women have a similar risk but later in life.
“Our findings underscore that women are not ‘protected’ from coronary events despite having lower plaque volumes,” said senior author Borek Foldyna, MD, PhD, an assistant professor in radiology at Harvard Medical School in Boston, in a press statement.
“Because women have smaller coronary arteries, a small amount of plaque can have a bigger impact. Moderate increases in plaque burden appear to have disproportionate risk in women, suggesting that standard definitions of high risk may underestimate risk in women.”
The current study included 4267 participants (2199 women) aged 60.4 years on average. It involved people who had stable chest pain but no previous diagnosis of coronary artery disease. Participants underwent coronary CT angiography and were tracked for about two years to see how plaque levels aligned with cardiac event risk.
Around 55% of the women in the group had coronary artery plaque versus 75% of the men. Risk of having a major cardiac event like a heart attack went up at a lower level of coronary plaque in women (20%) than in men (28%). Women with a 32% total plaque burden and men with a 42% total plaque burden both had a 50% increased risk of having a major adverse cardiovascular event compared with those without plaque. Similar findings were also seen for noncalcified plaque burden.
Overall, women in the study had a higher risk for cardiovascular events at a lower level of plaque burden than men and risk in women increased more steeply than risk in men.
“Our findings suggest that applying uniform thresholds across sexes to determine whether patients’ plaque measures put them at high risk for a major adverse cardiovascular event may underestimate risk in women,” said first author Jan Brendel, of the Cardiovascular Imaging Research Center in the Mass General Brigham Department of Radiology.
“Based on the apparent differences in risk trajectories between men and women, incorporating sex, and even age, into the interpretation of plaque metrics is an important next step toward more individualized risk assessment.”
