MINOCA (myocardial infarction with nonobstructive coronary arteries)
MINOCA is myocardial infarction with nonobstructive coronary arteries, defined by infarction criteria but less than 50 percent stenosis on angiography, requiring a search for the underlying mechanism such as plaque disruption, coronary spasm, spontaneous dissection, microvascular dysfunction, or embolism. Diagnosis pairs the infarction criteria with angiography and often cardiac MRI and intracoronary imaging, and treatment targets the identified cause.
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What this article covers
- Overview
Definition: MINOCA (myocardial infarction with nonobstructive coronary arteries) is a myocardial infarction meeting universal criteria but with less than 50 percent stenosis in any major coronary…
- Epidemiology
A notable minority of MIs, more common in women and younger patients than obstructive MI.
- Risk factors
Female sex and younger age relative to typical obstructive coronary disease.
- Pathophysiology
Plaque disruption: rupture or erosion of a nonobstructive plaque with transient thrombosis or embolization.
- Clinical features
ACS presentation: acute chest pain or an anginal equivalent with a rising troponin.
- Differential diagnosis
Obstructive coronary MI: an infarct with a culprit lesion, distinguished from MINOCA by an epicardial stenosis of 50 percent or more on angiography rather than nonobstructive coronaries (NSTEMI).
- Diagnosis
Establish with the infarction criteria plus nonobstructive angiography, then pursue the mechanism: MINOCA is diagnosed when the universal MI criteria are met (rising troponin with ischemia) and…
- Management
First, treat the identified mechanism specifically: antiplatelet (aspirin 81 mg PO daily) and statin (atorvastatin 40 to 80 mg PO daily) therapy for plaque disruption; a calcium channel blocker…
- Complications
Recurrent infarction or angina if the mechanism is untreated.
- Prognosis
Better on average than obstructive MI but with meaningful recurrent-event risk.
- Prevention
Treat and control the identified mechanism and its risk factors.
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