Myocardial infarction without coronary artery obstruction: frequency and clinical features in different cardiac magnetic resonance patterns; [Инфаркт миокарда без обструкции коронарных артерий: распространенность и клинико-демографические ассоциации паттернов, выявленных при магнитно-резонансной томографии сердца]

Objective. To study the frequency of different late gadolinium enhancement (LGE) patterns and clinical features of patients with myocardial infarction with myocardial infarction with non-obstructive coronary artery obstruction (MINOCA). Material and methods. Thirty-three patients treated in intensive care unit with a working diagnosis of MINOCA (39.4% male, median age 59 [48-65]) were included in the study. All patients underwent cardiac magnetic resonance (CMR) with LGE in addition to routine examination. According to the results of CMR, the patients were divided into 3 groups: with ischemic pattern of contrast enhancement (“true” MINOCA), with non-ischemic pattern (myocarditis, cardiomyopathies, etc.) and without changes (“unclassified” MINOCA). Results. Ischemic pattern of LGE was found in 6 (18.2%) patients, non-ischemic pattern in 9 (27.3%) and no changes 21 (54.5%) patients. In the group with non-ischemic pattern, myocarditis was diagnosed in 3 (33.3%) patients, takotsubo syndrome in two (22.2%), left ventricular hypertrophy in two (22.2%), dilated cardiomyopathy in one (11.1%) and arrhythmogenic biventricular cardiomyopathy in one (11.1%). Patients with ischemic pattern of LGE were characterized by predominantly male gender (83.3%, p = 0.008), significantly higher creatine creatine phosphokinase-MB (p = 0.05) and creatinine (p = 0.05), lower left ventricular ejection fraction (LV EF) (p = 0.048), higher blood pressure on admission (p = 0.016). Patients with non-ischemic pattern of LGE in one third of cases were of Asian race (p = 0.012) and were characterized by significantly higher level of leukocytes (p = 0.021) and neutrophils (p = 0.039), higher frequency of ST segment elevation on electrocardiogram (p = 0.017). Patients without detectable myocardial changes at CMR were predominantly women (83.3%, p = 0.008) and were characterized by the significantly lowest level of troponin I (p = 0.007). Conclusion. Non-ischemic pattern of contrast enhancement is more often detected in patients with working diagnosis of MINOCA at CMR. The presence of ischemic pattern is associated with traditional risk factors and was characterized by a more pronounced myocardial damage. © 2024 Bakoulev National Medical Research Center for Cardiovascular Surgery. All rights reserved.