A comparative analysis of clinical and epidemiological data and results of treatment of 7 patients suffering from myocardial infarction without obstructive coronary artery disease (main group) and 54 patients with their lesions (control group) aged 45,69,3 and 62,714,2 years, respectively. Both groups were dominated by men (85,7% and 72,2%, respectively). In the main group, dyslipidemia and hypertension were less common (14,3 and 28,6%, respectively) than in the control group (61,1 and 72,2%, respectively). At the same time, the former had a more burdened history of early cardiovascular events in close relatives in 28,6% of cases, and the latter-only in 5,6% of cases. Surgical tactics and features of double antiplatelet therapy in myocardial infarction without obstructive coronary artery disease did not differ from the standard approach. In both groups, active surgical tactics prevailed, consisting in performing percutaneous coronary intervention and installing a coronary stent in the infarct-related artery (85,7 and 83,3%, respectively). The choice of dual antiplatelet therapy in the main group did not differ from the control group and was characterized by a significantly higher frequency of clopidogrel administration (71,4 and 72,2%, respectively). When comparing the left ventricular ejection fraction before and after percutaneous coronary intervention, it turned out that in patients of the main group, in contrast to the control group, the value of the left ventricular ejection fraction did not change significantly (52,56,4 and 51,39,5, respectively). The etiology and pathogenesis of myocardial damage in patients suffering from myocardial infarction without obstructive coronary artery disease is characterized by significant heterogeneity, which requires additional examinations and differential diagnostics to identify the underlying causes of this condition.

Highlights. Patients with epicardial obesity develop myocardial fibrosis (the underlying mechanism of left ventricular diastolic dysfunction) the preclinical diagnosis of which is difficult to perform. In this regard, the search for non-invasive methods for diagnosing diastolic dysfunction at an early stage, including the methods of determining the serum level of biomarkers of heart failure and studying the parameters of left ventricular mechanics using speckle-tracking echocardiography, seems quite relevant.Background. Currently, the search for serum biomarkers and non-invasive methods for diagnosing diastolic dysfunction (DD) of the left ventricle (LV) at the preclinical stage in obese patients is relevant.Aim. To study the levels of heart failure biomarkers and their association with profibrotic factors and LV mechanics in patients depending on the presence of epicardial obesity (EO).Methods. Out of 143 men with general obesity, depending on the severity of EO, determined by the thickness of epicardial adipose tissue (tEАT), 2 groups of patients were identified: the EO (+) group with tEАT 7 mm or more (n = 70), and the EO (–) group with tEАT less than 7 mm (n = 40). The exclusion criteria from the study were: arterial hypertension, type 2 diabetes mellitus, coronary artery disease, and the presence of LVDD detected by echocardiography (echo). Levels of profibrotic factors (type I and type III collagen, procollagen type I C-terminal propeptide (PICP), matrix metalloproteinase-3 (MMP-3), transforming growth factor-β (TGF-β), vascular endothelial growth factor A (VEGF-A), sST2, and NT-proBNP were determined in all patients using enzyme immunoassay. With the help of speckle-tracking echocardiography, the mechanics of LV were analyzed.Results. The EO (+) group presented with increased sST2 level (22.11±7.36 ng/mL) compared to the EO (–) group (sST2 level 9.79±3.14 ng/mL (p<0.0001). In the EO (+) group, a significant influence of tEAT on sST2 level was identified (F = 8.57; p = 0.005). In the EO (+) group, an increase in the level of MMP-3, type I collagen, type III collagen, PICP, transforming growth factor-β, and VEGF-A was revealed. Moreover, in the EO (+) group, a statistically significant relationship between sST2 and type III collagen was revealed (p = 0.01). When comparing the parameters of speckle-tracking echo, the EO group (+) presented with increased LV untwisting rate of –128.31 (–142.0; –118.0) deg/s-1 (p = 0.002), and increased time to LV peak untwisting rate of – 476.44 (510.0; 411.0) msec compared with the EO group (–) (p = 0.03). Moreover, a significant association between LV untwisting rate and sST2 level was revealed in the EO (+) group (r = 0.35; p = 0.02).>˂0.0001). In the EO (+) group, a significant influence of tEAT on sST2 level was identified (F = 8.57; p = 0.005). In the EO (+) group, an increase in the level of MMP-3, type I collagen, type III collagen, PICP, transforming growth factor-β, and VEGF-A was revealed. Moreover, in the EO (+) group, a statistically significant relationship between sST2 and type III collagen was revealed (p = 0.01). When comparing the parameters of speckle-tracking echo, the EO group (+) presented with increased LV untwisting rate of –128.31 (–142.0; –118.0) deg/s-1 (p = 0.002), and increased time to LV peak untwisting rate of – 476.44 (510.0; 411.0) msec compared with the EO group (–) (p = 0.03). Moreover, a significant association between LV untwisting rate and sST2 level was revealed in the EO (+) group (r = 0.35; p = 0.02).Conclusion. The data obtained indicate that patients with EO have LVDD, which could not be detected using echo criteria for LVDD, and the determination of serum levels of the heart failure biomarker - sST2 can be used for the diagnosis of LVDD at the early stage.