Cardiovascular magnetic resonance in myocardial infarction with non-obstructive coronary arteries patients: A review

Abstract

The diagnosis of myocardial infarction with non-obstructive coronary arteries (MINOCA) necessitates documentation of an acute myocardial infarction (AMI), non-obstructive coronary arteries, using invasive coronary angiography or coronary computed tomography angiography and no clinically overt cause for AMI. Historically patients with MINOCA represent a clinical dilemma with subsequent uncertain clinical management. Differential diagnosis is crucial to choose the best therapeutic option for ischemic and non-ischemic MINOCA patients. Cardiovascular magnetic resonance (CMR) is able to analyze cardiac structure and function simultaneously and provides tissue characterization. Moreover, CMR could identify the cause of MINOCA in nearly two-third of patients providing valuable information for clinical decision making. Finally, it allows stratification of patients with worse outcomes which resulted in therapeutic changes in almost half of the patients. In this review we discuss the features of CMR in MINOCA; from exam protocols to imaging findings.

Keywords: Acute coronary syndrome unobstructed coronaries; Acute myocardial infarction; Acute myocarditis; Cardiovascular magnetic resonance; Takotsubo cardiomyopathy.

Figure 1

Cardiovascular magnetic resonance findings in patients with myocardial infarction with non-obstructive coronary arteries. Adapted from Pasupathy S et al[13]. CMR: Cardiovascular magnetic resonance; MINOCA: Myocardial infarction with non-obstructive coronary arteries.

Figure 2

Thirty-three years old male presented with acute chest pain, nonspecific short-tau wave abnormalities, increased troponin values and negative invasive coronary angiography. A: Short axis T2-weighted short-tau inversion recovery image, a transmural hyperintense areas with central hypointensity is seen in the inferior wall (arrows); B: Late gadolinium enhancement image: the hypointense areas correspond with areas of microvascular obstruction and is thought to represent myocardial hemorrhage (arrows); C: T2 map; D: T1 map. The cardiovascular magnetic resonance study is in accordance with acute myocardial infarction with sign of microvascular obstruction and hemorrhage.

Figure 3

Thirty-seven years old male presented with acute chest pain, increased troponin values and negative invasive coronary angiography. A: A short axis T2-weighted short-tau inversion recovery image, a subepicardial and hyperintense areas is seen in the infero-lateral wall (arrows); B: Late gadolinium enhancement image with evidence of the same alteration (arrows); C: T2 map; D: T1 map. The cardiovascular magnetic resonance study is in keeping with acute myocarditis.

Figure 4

Thirty eight years old female presented with acute chest pain, increased troponin values and negative coronary angiogram. A and B: Diastolic and systolic 4-chamber cine-SSFP images: there is a minimum “apical ballooning” appearance with a relative left ventricle apical akinesia with preserved function of the remaining segments, which causes the typical “apical ballooning” appearance; C and D: T2-weighted short-tau inversion recovery images with evidence of myocardial edema in apical segments (arrows); E and F: Ate gadolinium enhancement images without presence of areas of increased signal intensity; G-I: T1-map; J-L: T2-map. M-O: T1 native, extracellular volume and T2 mapping bull’s eye, there is a marked increase in values in the apical segments (T1 mapping: 1350 ms; extracellular volume: 38%, T2 mapping: 70 ms). The cardiovascular magnetic resonance images are in keeping with Takotsubo syndrome.