In the last few years many women died from heart attacks without blood clots. Autopsies showed that their coronary arteries were wide open and yet they died of heart attacks. Subsequent research showed that men or women can die from heart attacks when the coronary arteries are in spasm. But prolonged stress can close the blood supply to the heart muscle also when only coronary arteries are in spasm. There is a new name for this condition: “myocardial infarction with non-obstructive coronary arteries” or MINOCA.
There is a related condition, INOCA, which stands for ischemia with non-obstructed coronary arteries. However, the difference is that with INOCA there is no heart attack, just chest pain due to ischemia.
Symptoms of MINOCA and frequency
Dr. Noel Bairey Merz, MD is the director of the Barbra Streisand Women’s Heart Center at Cedars-Sinai Medical Center in Los Angeles. He said: “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.” He also stated that MINOCA occurs more in women than in men:
- 25% to 30% of all heart attacks in women are from MINOCA
- Less than 10% of all heart attacks in men are from MINOCA
An example of a patient with MINOCA
A middle-aged woman from Yucaipa, CA had a healthy lifestyle. She was a vegetarian, had a normal cholesterol and blood pressure. There was no family history of heart disease. She finished a 5 K run the weekend her chest symptoms started. She saw her primary care doctor the morning after her chest pain. He told her to go to the emergency room of the hospital. They took blood for a troponin level and an ECG.
Results of the troponin level
Troponin is a heart enzyme, which the heart muscle only releases when there was damage to the heart muscle. Typically, this only happens when you have a heart attack. In her case there was an elevation of the troponin level. The diagnosis was that she had a heart attack. The physician of the emergency room admitted her to the hospital. The following she had an angiogram. This showed open coronary arteries with no atheromatous deposits. The clinical staff sent her home with no further follow-up.
Examples of problems diagnosing INOCA
Here are the findings of a survey from January 2023. This is 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.
- More than half (54%) said their symptoms negatively affected their relationship with their partner or spouse.
Heart Attacks without Blood Clots
Conclusion
There are heart attacks that are not caused by blockage of coronary arteries. They are caused by acute coronary artery spasms. This has the name MINOCA (myocardial infarction with non-obstructive coronary arteries). You also can have chest pains from spasm of the coronary arteries only without evidence of a heart attack. This has the name INOCA (ischemia with non-obstructed coronary arteries). Coronary arteriograms don’t show any blood clots with either MINOCA or INOCA. Physicians still have to catch up with these newest findings. The key point to remember for a patient with chest pain is to go to the nearest emergency room of a hospital for an investigation with a troponin blood test and an ECG.
