"Cardiovascular disease is still the leading cause of death in women, and actually, we are no longer making gains in cardiovascular mortality in both men and women. And the fastest growing death rate is in middle aged women," Michos said.
She said cardiac computed tomography (CT) calcium scoring is a good way to perform a baseline assessment of the 10-year risk in women for a heart attack. This can help guide if a patient should be put on preventive statin and aspirin therapy.
"It is important to note in terms of sex differences, although women have a lower prevalence of calcium at any given age compared to men. Whenever calcium is present, that actually carries a greater prognostic risk in women than men," she explained.
On coronary CT angiography (CCTA), she said women often have plaque, but it is usually non-obstructive plaque in the setting of angina. However, non-obstructive disease is still highly associated with major adverse cardiovascular events in both men and women. In women, any high-risk plaques confer a greater risk compared to men. Non-obstructive disease in the left main coronary artery is also associated with a higher cardiac event risk in women.
Michos said physicians need to pay more attention to symptoms in women.
"Women are more likely to have angina compared to men, but in the setting of angina, women are more likely to have non-obstructive disease," Michos explained. "We did such a disservice for years when women would have signs and symptoms of ischemic heart disease and even positive stress tests. They would have a CTA or an angiography and it would show no obstruction and they would be told, ' Oh, it's a false positive, you are fine.'"
She said studies have shown this is not the case, and many women actually have a condition now known as ischemia and no obstructive coronary artery disease (INOCA). Women tend to have smaller arteries than men, so smaller amounts of plaque volume can actually cause ischemia associated with INOCA.
"INOCA is not only associated with risk for major adverse cardiovascular events, but even in comparison with patients with obstructive disease, there can be similar angina burden, similar reduced quality of life, as well as similar number of ischemic segments on stress imaging. So, it is important that this is recognized because these women deserve a diagnosis. Their symptoms are often brushed off, and it is important that we take their symptoms seriously so we can get them on preventive agents such as statins and ARBS, and we can get them on things to control their symptoms, such as calcium channel blockers, nitrates and beta blockers."
Once you rule out obstruction on imaging, you can estimate coronary blood flow reserve, she said. "The artery should be able to dilate twice its normal size, but if not, and their coronary flow reserve is less than 2, then that is a really adverse marker for future events and that is part of the diagnosis for coronary microvascular disfunction (CMD)," Michos said.
Spontaneous coronary artery dissection (SCAD) is another condition found in women at a much higher rate than men. This condition is where the layers of a coronary vessel can tear and the tissue hanging into the vessel can block blood flow. There were several sessions at SCCT on this condition and what to look for in the CT imaging. It often presents as a STEMI or non-STEMI on ECG and there are elevated troponins, so these patients are often taken to the cath lab with the belief it is a heart attack. Michos said invasive angiograms are still the recommended front line imaging test for SCAD because it has better image resolution inside the vessel. If a patient presents later, SCAD can be seen on higher-quality coronary CT.
Up to 60-70% of people who present with SCAD may have fibromuscular dysplasia (FMD), so she said it is important to do a head to pelvis CT scan to look for other areas FMD and aneurisms.
She also said there are other factors that also increase a women's risk of heart disease, including early menopause, adverse pregnancy outcomes include preeclampsia and having autoimmune conditions like lupus rheumatoid arthritis.