This mysterious type of heart attack can be deadly, and it’s the kind women are more likely to experience

Miniature doctor and nurse "team specialists" observing and discussing about human heart, Science and Medical ConceptNixx Photography/Shutterstock

When we think of a heart attack, we tend to think of a blocked artery. Cholesterol plaque builds up on artery walls; eventually there’s a blockage, and the heart stops. But a significant number of heart attacks occur in people with no blockage and very little plaque, according to the NYU Langone Medical Center. This type of attack is known as MINOCA, an acronym for “myocardial infarction [medical lingo for heart attack] with non-obstructive coronary arteries.” Doctors tend to think of MINOCA as less severe and not that dangerous. That’s just not true, according to a new study. Check out 9 things everyone should know about heart attacks.

Researchers at the University of Alberta in Canada followed more than 36,000 patients for 12 years to determine the frequency and dangers of MINOCA. The results, published in the International Journal of Cardiology, showed that 6 percent of heart attack patients had a MINOCA—with little to no artery plaque. About 1 percent died in the hospital after their MINOCA (compared with 2.7 percent of those who had blocked-artery heart attacks). Over the next five years, 11 percent of MINOCA patients died, compared with 16 percent of patients with traditional heart attacks. The research also revealed that the gender split for men and women suffering a MINOCA was 50-50; with regular heart attacks, the split is 75 percent male, 25 percent female. Make sure your diet includes at least some of these 50 best foods for your heart.

According to study author Kevin R. Bainey, MD, assistant professor of medicine in the Division of Cardiology at the University of Alberta in Edmonton, Canada, and his colleagues, women—and their doctors—need to take note that women are more likely to have MINOCA. Previous research has found that MINOCA can be up to five times more common in women than in men. Learn more about the physical and emotional ways that heart disease is different for women.

“Historically, MINOCA has been seen as a benign condition, and patients are commonly sent home without any treatment or lifestyle advice,” Dr. Bainey told CTVnews.com. “Yet we found that after one year’s time, 5 percent of patients either had another heart attack or died of a heart attack. Patients need to know that this condition is real, it is associated with adverse outcomes, and they need to probe their physicians for more information about the condition and ways to prevent a second heart attack, including making important lifestyle changes like eating healthier and exercising.” Check out 8 sneaky heart-attack symptoms women may ignore.