Myocardial Infarction with Nonobstructive Coronary Arteries (MINOCA)

Abstract

Myocardial infarction with nonobstructive (<50% stenosis) coronary arteries (MINOCA) is a syndrome involving different etiologies: acute myocardial infarction (AMI) in approximately 26%, acute myocarditis in 27–33%, and takotsubo cardiomyopathy in approximately 9–11% of cases. In patients with MINOCA, cardiac magnetic resonance (CMR) has shown to establish a definitive diagnosis in 70% of patients, whereas around 30% of patients with MINOCA have normal CMR and a good clinical outcome. CMR allows accurate evaluation of wall motion abnormalities using steady-state free precession cine imaging, the presence of myocardial edema using T2-weighted imaging, and the identification of myocardial fibrosis through late gadolinium enhancement (LGE) sequences. In MINOCA patients with underlying AMI, coronary computed tomography angiography allows better evaluation of nonobstructive plaque burden than invasive coronary angiography and in some cases can identify ostial occlusion of small branches.