The prevalence of ischemic pattern of heart damage in patients with acute myocardial infarction depending on the presence of obstructive coronary artery disease: magnetic resonance study

Currently, there are practically no works that are devoted to the analysis of different types of damage to ischemic and nonischemic patterns in patients with acute myocardial infarction (AMI), depending on the nature of atherosclerotic lesions of the coronary arteries.In this regard, the aim of this work was to evaluate the frequency of ischemic pattern of heart damage in patients with AMI depending on the presence of obstructive coronary artery disease.Material and Methods. The study retrospectively included patients with a working diagnosis of acute coronary syndrome (ACS) who underwent contrast-enhanced cardiac magnetic resonance (MR) imaging (CMR) during the first week after hospitalization. A 1.5 T CMR was performed using a standard protocol. T2-WI, T1-WI, and IR-images were visually assessed for edema and scar/necrosis, respectively. The pattern of acute ischemic damage to the left ventricular (LV) myocardium was an increase in the signal intensity on T2-WI as a sign of myocardial edema and late gadolinium enhancement (LGE) with a typical ischemic nature of contrast enhancement: subendocardial/subtransmural/transmural. The non-ischemic nature of myocardial injury was defined as intramyocardial/subepicardial LGE.Results. Based on invasive coronary angiography (ICA) data, patients were divided into two groups: group of myocardial infarction (MI) and coronary artery disease (MICAD group) and group of MI and non-obstructive coronary arteries (MINOCA group). It was found that the frequencies of occurrence of subendocardial pattern of cardiac LGE in early CMR did not differ in the groups of AMI patients against the background of obstructive and non-obstructive coronary artery disease (CAD). The most characteristic MR-pattern in MICAD patients was transmural LGE, including that in combination with microvascular obstruction (MVO). The most characteristic MR-pattern in MINOCA patients was mid-wall/insertion point LGE. Subepicardial LGE occurred with equal frequency in MICAD and MINOCA patients.Conclusion. The most pathognomonic MR-pattern of myocardial damage in AMI against the background of obstructive CAD was the transmural type of LGE with or without the phenomenon of MVO. Identification of the subendocardial type of LGE in patients with MINOCA allowed to stratify these patients into a higher risk group with a further change in treatment tactics.