The Heart Attack You Didn't See Coming

A Heart Attack With Open Arteries MINOCA stands for myocardial infarction with non-obstructive coronary arteries. As its name suggests, it's a type of heart attack without any blockages (obstructions) in the main coronary arteries. A related condition, called INOCA (ischemia with non-obstructed coronary arteries), has many of the same symptoms but without the actual heart attack. When diagnosing a heart attack, doctors typically look for blockages in the main coronary arteries. If any are found, they use various methods (such as bypass surgery, angioplasty, or stents) to restore blood flow. Then they prescribe medication, dietary changes, exercise, and other lifestyle changes to prevent more arterial plaque and clots from forming. Conrad, who lives in Yucaipa, CA, already had a healthy lifestyle. She was a vegetarian with normal blood pressure and cholesterol, and no family history of heart disease. In fact, she'd finished a 5K the weekend before her symptoms started. The morning after, her primary care doctor told her she'd probably had a heart attack and should get to the ER. A blood test showing elevated levels of a protein called troponin later confirmed that. She was admitted to the hospital and given an angiogram (imaging of the inside of blood vessels — in this case, in the heart). There was no sign of plaque in her main coronary arteries. "I'll never forget it," she says. "One of the techs in the room said, 'Your arteries are perfectly clear. You should celebrate with some McDonald's french fries.'" Conrad says that before she was discharged, she wasn't given any explanation for her heart attack, no prescription for medication, not even a referral to a cardiologist. "My husband and I were driving home, and we were like, 'OK, what now?'" MINOCA may account for up to 25% to 30% of all heart attacks in women (and less than 10% in men), according to C. Noel Bairey Merz, MD, director of the Barbra Streisand Women's Heart Center at Cedars-Sinai Medical Center in Los Angeles. The symptoms of MINOCA are the same as those of a classic heart attack that happens in someone with coronary artery disease. But because no blockages are found in the main coronary arteries, patients often leave the hospital unsure about what caused their MINOCA heart attack and how to prevent another one. During the next 3 years, Conrad estimates she had 20 more episodes. None were as severe as the first one and, as far as she knows, none were heart attacks. She visited the ER three more times, but after being sent home as before, she stopped going. Searching for a Cause As with Conrad, MINOCA or INOCA can seriously affect a person's life. Consider the findings of a survey published in January 2023, based on 297 people in an international INOCA patient support group: 34% had lived with symptoms of chest pain, pressure, or discomfort for more than 3 years before their INOCA diagnosis. 78% were wrongly told at some point that their symptoms weren't related to their heart. 75% cut their work hours or stopped working altogether due to their condition. About 70% said their mental health and life outlook had declined. What Happens in the Heart Cardiologist Harmony Reynolds, MD, of NYU Langone Health and colleagues recently studied the blood vessels of 301 women who had had heart attacks. In their study, published in 2021, they took a different approach. Instead of using the typical angiogram to look for arterial plaque, they used various forms of imaging with higher resolutions. This allowed them to look beyond the main coronary arteries and search for trouble elsewhere. With 85% of MINOCA patients in the study, they were able to attribute the women's heart attacks to small plaques and clots in these smaller blood vessels. "Your arterial system is a lot like a tree," Reynolds says. "It has large trunks and smaller and smaller branches. If a clot forms in the trunk, it can get carried into a smaller branch. 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."