You've heard that cholesterol can lead to clogged arteries and raise your risk for a heart attack, and that's true. But what you might not realize is that you can have a heart attack even if your arteries don't have any blockages. That's the case for at least one-third of women who've had heart attacks, says C. Noel Bairey Merz, MD, director of the Barbra Streisand Women's Heart Center at Cedars-Sinai in Los Angeles. Yet even their doctors often don't realize what's happened.
When Merz and her colleagues took a group of women who had complained of chest pain yet were told not to worry because imaging tests (angiograms) didn't show any blockages, they found that 8% had scars on their heart -- indicating that a heart attack had happened. Their research was published in 2018 in the journal Circulation.
How is that possible? While a blocked artery is a major cause of heart attacks, it's hardly the only one. Acute myocardial infarction, what most people call a heart attack, simply means that blood flow to the heart's own blood vessels is cut off so that heart muscle cells die, says Merz.
Much of the time, that happens because a fatty deposit (called a plaque) that's already clogging an artery becomes unstable and breaks off, further slowing or stopping blood flow. But even smaller amounts of plaque that don't normally mess with circulation can break off and form blood clots, which then restrict blood flow and cause small heart attacks, says Merz.
"Women can also have heart attacks from less common problems, like SCAD -- spontaneous coronary artery dissection -- which is when the inner lining of an artery separates," she adds. Another possible cause is a spasm in a coronary artery, which could restrict blood flow if it goes on long enough or ends up forming a clot.
Unfortunately, women who have a heart attack due to one of these lesser-known causes tend not be taken seriously. "Doctors didn't believe that they had a real heart attack," Merz says of the women with chest pain who were found to have heart scars in the Circulation study.
The takeaway: If you have persistent or severe chest pain, see a cardiologist. If you're told not to worry because your arteries are open, seek a second opinion. Other tests, such as a cardiac MRI or a coronary flow reserve test, might reveal that you really do have a serious heart issue -- maybe you've even had a heart attack -- and that treatment is called for.
Ask Your Doctor
What can I do for my heart?
What symptoms might suggest a heart attack?
What heart screening tests do I need?
Where can I go for a second opinion?
Your primary care doctor should be able to refer you to a different cardiologist, or you can head to a medical center that has a specialized women's heart program.
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