Understanding MINOCA

(Heart attack without major artery blockages)

What is MINOCA?

MINOCA stands for Myocardial Infarction with Non-Obstructive Coronary Arteries. It refers to a heart attack (MI) where tests show damage to the heart muscle, but the coronary arteries have less than 50% narrowing — meaning no significant blockage to explain the event.

MINOCA is a syndrome, not a single disease — it has many possible underlying causes.

Who Gets MINOCA?

More common in women (about 2–3 times more likely than in men)

Seen in people with or without traditional risk factors

Often occurs at younger ages than typical heart attacks

Accounts for about 6–8% of all heart attacks

What Causes MINOCA?

Several mechanisms can injure the heart muscle without a big blockage:

Coronary vasospasm — sudden artery narrowing

Coronary microvascular dysfunction — small vessels not supplying enough blood

Spontaneous coronary artery dissection (SCAD) — tear in artery wall

Clot or embolus that dissolves before testing

Stress-induced heart failure (Takotsubo syndrome)

Other rare or unknown mechanisms

Symptoms of MINOCA

The symptoms are often the same as a typical heart attack:

Chest pain, pressure, or discomfort

Sweating, nausea, lightheadedness

Shortness of breath

Pain in arms, jaw, back, or neck

CMD often causes angina-like symptoms, but tests for blockages may come back “normal,” which can delay diagnosis.

How is MINOCA Diagnosed?

Cardiac MRI

Intravascular imaging (OCT or IVUS)

Tests for vasospasm or clotting disorders

How is MINOCA Treated?

Treatment depends on the underlying cause, but may include:

General Measures

Antiplatelet medications (aspirin, sometimes clopidogrel)

Statins to improve vessel health

Beta-blockers or ACE inhibitors if appropriate

Lifestyle changes: stop smoking, heart-healthy diet, exercise, stress management

Cause-Specific Treatments

For example:

Vasospasm → calcium channel blockers & nitrates

SCAD → conservative care & careful monitoring

Takotsubo → heart failure management

Beta-blockers are usually avoided in pure vasospasm, as they may worsen symptoms in some patients.

Takeaway

MINOCA is a real heart attack, even when coronary arteries appear normal on angiography. Because MINOCA has multiple possible causes, careful evaluation is essential to guide the right treatment. If you have experienced symptoms or a prior diagnosis of MINOCA, schedule an appointment with Insight Heart Health for a comprehensive assessment.