Myocardial ischemia in nonobstructive coronary arteries: A review of diagnostic dilemmas, current perspectives, and emerging therapeutic innovations

Table 8 Cardiac magnetic resonance findings and diagnoses in myocardial infarction with nonobstructive coronary arteries

Cause of MINOCA	CMR findings	Description
Acute myocarditis	Lake Louise criteria	CMR shows myocardial edema, capillary leaks, hyperemia, and necrosis/fibrosis. Lake Louise criteria include T2 weighted imaging for edema and T1 weighted imaging before and after contrast for tissue characterization (LGE pattern)
	LGE	LGE typically shows subepicardial or transmural enhancement, often in a nonvascular distribution (inflammatory infiltration rather than ischemic)
	T2 weighted imaging	T2 signal hyperintensity, indicating myocardial edema
	T1 weighted imaging	Helps identify myocardial fibrosis and scar tissue
Takotsubo cardiomyopathy	RWMA	CMR shows apical ballooning with increased myocardial strain in the apex of the (LV) but with absence of coronary artery obstruction
	LGE	LGE is typically absent or minimal in Takotsubo cardiomyopathy, helping to distinguish it from myocardial infarction
	T2 weighted imaging	T2 hyperintensity may show myocardial edema in the involved regions of the LV
	No obstructive coronary disease	No significant coronary artery blockage or stenosis is identified
Plaque rupture	LGE	LGE in a subendocardial or transmural pattern corresponding to a vascular territory, often localized to the area of infarction after plaque rupture
	T2 weighted imaging	Edema is typically seen in a coronary regional distribution, reflecting the infarcted area from the ruptured plaque
	No obstructive coronary disease	Coronary artery spasm or microvascular dysfunction might be present but not significant obstruction
Plaque erosion	LGE	LGE may be present in a subendocardial or transmural pattern, typically corresponding to a vascular territory
	T2 weighted imaging	Edema localized to the region supplied by the affected artery
	No significant obstruction	Coronary imaging may show plaque erosion or microembolism, but not significant stenosis

MINOCA: Myocardial infarction with nonobstructive coronary arteries; CMR: Cardiac magnetic resonance; LGE: Late gadolinium enhancement; RWMA: Transient regional wall motion abnormalities; LV: Left ventricle.