It’s become clear in recent years that when women suffer heart attacks, their symptoms often differ from those of men.
And that’s just for a classic heart attack. There’s another type of heart attack that’s on the rise in women that is even harder to see coming…
This type of heart attack is called myocardial infarction with non-obstructive coronary arteries, or MINOCA.
When diagnosing a heart attack, doctors usually examine the coronary arteries for blockages. But in MINOCA, those blockages don’t exist. Here’s what you need to know…
The sinister specter of MINOCA
It used to be thought that MINOCA only represented 6 to 14 percent of heart attacks. But for women, MINOCA may actually account for 25 to 30 percent of all heart attacks.
The symptoms of MINOCA are the same as for a typical heart attack. But because it’s not caused by coronary artery blockage, the usual methods for treating heart attack — stents, angioplasty, bypass surgery — don’t work for MINOCA. That often leaves patients unsure about what caused their MINOCA or what to do to prevent another one.
A related condition, called INOCA, or ischemia with non-obstructed coronary arteries, has many of the same symptoms but without the actual heart attack.
A survey of 297 patients in an international INOCA patient support group found:
- 34 percent had been living with symptoms of chest pain, pressure or discomfort for more than three years before their INOCA diagnosis
- 78 percent were wrongly told their symptoms weren’t related to their heart
- 75 percent cut their work hours or stopped working altogether due to their condition
- 70 percent said their mental health and outlook on life had declined
What’s the cause?
In one 2021 study, researchers took a different approach in studying 301 women who had heart attacks.
Instead of using an angiogram, they used various forms of imaging with higher resolutions that allowed them to examine the vessels beyond the main coronary arteries. In 85 percent of the MINOCA patients in the study, the researchers were able to attribute their heart attacks to small plaques and clots in smaller blood vessels.
This is similar to a common cause of heart disease in women known as coronary microvascular syndrome. When this develops, plaque accumulates in very small arteries of the heart known as microvessels.
Cardiologist Dr. Harmony Reynolds of NYU Langone Health, who was one of the researchers in the study, describes the arterial system as a sort of tree, with large trucks and smaller branches. “If a clot forms in the trunk, it can get carried into a smaller branch,” Reynolds tells WebMD. “If the clot is big enough, it can knock out the entire branch and kill a small part of the heart muscle. That’s what we think happens in some MINOCA patients.”
MINOCA patients are often told they didn’t have a heart attack, and this misdiagnosis can be deadly. According to Reynolds, in the four years after someone has a MINOCA event, they have a 13 percent chance of death from any cause and a 7 percent chance of having another heart attack.
What to do about MINOCA
Investigators still aren’t sure why MINOCA is more common in women than men. Some researchers theorize it could be due to hormones, hormone therapy or the fact that women are physically smaller on average than men. That makes their hearts and blood vessels smaller, so arterial blockages and clots that may not show up on conventional imaging like an angiogram can do more damage.
Not all MINOCA is caused by plaque buildup in the heart’s small arteries. For example, there is spontaneous coronary artery dissection, where interior of an artery wall tears and causes a blockage that feels like a classic heart attack. Or blood vessels can spasm, interrupting normal blood flow and producing heart attack-like symptoms.
Other potential causes include myocarditis, or inflammation of the heart muscle, and stress cardiomyopathy, a reaction to a surge of adrenaline.
If you experience chest pain, pressure or discomfort, make sure your doctor examines all these potential causes so that they can prescribe the proper treatment. For instance, if it’s caused by artery spasms, there is medication that can be prescribed to manage the spasms.
Following a heart-healthy lifestyle may not offer 100 percent protection against MINOCA, but it can certainly help. Make sure you’re eating a healthy diet and getting plenty of exercise, and try to keep your stress levels under control.
Sources:
The Heart Attack You Didn’t See Coming — WebMD
Ischemia with no obstructive coronary artery disease (INOCA): A patient self-report quality of life survey from INOCA international — International Journal of Cardiology
Uncommon heart attack, found more often in women, needs a second look — American Heart Association
Heart Attack Symptoms in Women — American Heart Association