Women who are postmenopausal are at higher risk of heart attacks than men of similar age and levels of atherosclerosis, according to results of a large study presented at EACVI 2023, a scientific congress of the European Society of Cardiology (ESC).
“Since atherosclerotic plaque burden is emerging as a target to decide the intensity of therapy to prevent heart attacks, the findings may impact treatment. Our results indicate that after menopause, women may need a higher dose of statins or the addition of another lipid-lowering drug,” said lead author, Sophie E. van Rosendael, of Leiden University Medical Centre, the Netherlands.
She added that, “We also found that women are more likely to have non-obstructive disease. It was formerly thought that only obstructive atherosclerosis caused myocardial infarction but we now know that non-obstructive disease is also risky.”
The study appears in the European Heart Journal – Cardiovascular Imaging.
Atherosclerosis is the narrowing of arteries due to deposits of fat and cholesterol called plaque. In general, women develop atherosclerosis later in life than men and have heart attacks later too, in part because of the protective effect of estrogen.
This study examined whether the prognostic importance of atherosclerotic plaques are the same for women and men at different ages.
The study included 24,950 patients referred for coronary computed tomography angiography (CCTA) and enrolled in the CONFIRM registry, which was conducted in six countries in North America, Europe, and Asia. CCTA is used to obtain 3D images of the arteries in the heart.
Total atherosclerotic burden was rated using the Leiden CCTA score, which incorporates the following items for each coronary segment: plaque presence (yes/no), composition (calcified, noncalcified or mixed), location, and severity of narrowing, for a final value of 0 to 42. Patients were divided into three categories previously found to predict the risk myocardial infarction: low atherosclerotic burden (0 to 5), medium (6 to 20), and high (over 20).
The investigators also analyzed sex differences in the rates of major adverse cardiovascular events, which included all-cause death and myocardial infarction, after adjusting for age and cardiovascular risk factors (hypertension, high cholesterol, diabetes, current smoking and family history of coronary artery disease).
A total of 11,678 women (average age 58.5 years) and 13,272 men (average age 55.6 years) were followed for 3.7 years. The study showed an approximately 12-year delay in the onset of coronary atherosclerosis in women: the median Leiden CCTA risk score was above zero at age 64 to 68 years in women versus 52 to 56 years in men (p<0.001). In addition, the overall plaque burden was significantly lower in women, who had more non-obstructive disease.
“The results confirm the previously reported delay in the start of atherosclerosis in women” van Rosendael said.
In postmenopausal women (age 55 years and older), the risk of major adverse cardiovascular events was higher than men for given level of arteriosclerosis. In postmenopausal women, compared to those with a low burden, those with a medium and high burden had 2.21-fold and 6.11-fold higher risks of major cardiovascular adverse events.
“In this study, the elevated risk for women versus men was especially observed in postmenopausal women with the highest Leiden CCTA score. This could be partly because the inner diameter of coronary arteries is smaller in women,” van Rosendael said.