Background/Objectives: Despite growing evidence on quantitative computed tomography (CT) analysis of coronary plaques and pericoronary adipose tissue (PCAT), their association with myocardial perfusion (MP) in patients with first acute myocardial infarction (AMI) with obstructive coronary artery disease (MICAD) and non-obstructive coronary arteries (MINOCA) remain unclear. The aim of this study was to assess the relationship between quantitative CT coronary plaque components and PCAT characteristics with MP, myocardial blood flow (MBF) and coronary flow reserve (CFR) obtained by dynamic single-photon emission computed tomography (SPECT) in patients with AMI. Methods: Patients with a first episode of AMI were included in the study. All patients underwent coronary CT angiography with quantitative assessment of plaque volume (PV) and burden (PB), as well as PCAT volume and attenuation. Dynamic SPECT was performed on cadmium–zinc–telluride gamma-camera for quantitative assessment of MP parameters, stress and rest MBF, and CFR. Results: A total of 31 patients (median age 62 [56–70] years) were analyzed, including MICAD (n = 21) and MINOCA (n = 10). MICAD patients had significantly higher total PV and PB, mainly due to non-calcified and fibrofatty components (p < 0.05), while low-attenuation (LAP) and calcified plaques (CP) did not differ between groups. PCAT volumes were higher in MICAD (p < 0.05), whereas PCAT attenuation showed no differences. Dynamic SPECT revealed lower stress MBF and CFR in MICAD (p < 0.05). Correlation analysis showed positive associations of PV and PB with MP summed stress and rest scores, except LAP or CP; PB was negatively associated with MBF. In addition, PCAT volume correlated negatively with stress and rest MBF and CFR, as well as PCAT attenuation correlated positively with stress-induced MP abnormalities. Conclusions: Patients with MICAD demonstrated a greater extent of atherosclerosis and larger PCAT volume compared with MINOCA. Moreover, PCAT volume demonstrated inverse associations with MBF and CFR, indicating a potential link between PCAT characteristics and microvascular dysfunction.

Aim. To compare standard indices of myocardial perfusion scintigraphy (MPS) and quantitative indicators of myocardial dynamic single-photon emission computed tomography (SPECT) in patients with non-obstructive coronary artery disease (NOCAD).Material and methods. The study included patients with symptoms or signs of myocardial ischemia and NOCAD (<50%). All patients underwent dynamic myocardial SPECT with assessment of standard MPS indices (summed stress score (SSS), summed rest score (SRS), summed difference score (SDS)) and quantitative indicators (stress and rest myocardial blood flow (MBF), myocardial flow reserve (MFR) and stress/rest MBF difference (ΔMBF)).Results. According to MPS, 15 (26%) patients had signs of myocardial perfusion dysfunction (SSS ≥2,0). Standard MPS indices had low values as follows: SSS 0,0 (0,0; 2,0), SRS 0,0 (0,0; 0,0), SDS 0,0 (0,0; 2,0). According to dynamic myocardial SPECT, 22 (38%) patients had a reduced MFR <2,0. Quantitative indicators were characterized by greater variability compared to the MPS data as follows: stress MBF 1,34 (1,03; 1,64) ml/min/g, rest MBF 0,58 (0,42; 0,73) ml/min/g, MFR 2,42 (1,48; 2,85), ΔMBF 0,68 (0,36; 1,09). In 7 (12%) patients, ischemic myocardial changes (SSS ≥2,0) was associated with a reduced MFR <2,0, and in 28 (48%) without signs of ischemia (SSS <2,0) the MFR was within normal values ≥2,0. However, 15 (26%) had a normal radiopharmaceutical distribution and a reduced MFR, which may indicate the initial stages of microvascular dysfunction, which did not lead to myocardial ischemia.Conclusion. The dynamic SPECT allows in ~30% of cases to identify MBF and MFR disorders in NOCAD patients with normal results of standard SFM.

Aim. To study quantitative parameters of coronary atherosclerosis, according to computed tomography coronary angiography (CTCA), and to identify their association with the level of cardiac biomarkers in patients with acute myocardial infarction (MI).Material and methods. The study included patients with newly diagnosed MI. Depending on the coronary artery (CA) stenosis, two groups were formed: 1) MI with obstructive CA ≥50% (MICAD); 2) MI with non-obstructive CA <50% (MINOCA). All patients were assessed for cardiac biomarkers and underwent CTCA.Results. The study included 31 patients as follows: MINOCA group consisted of 10 patients (5 men aged 68 (57; 79) years); MICAD group — 21 patients (13 men aged 62 (56; 68) years). When analyzing cardiac biomarker levels, a significant increase in cardiac troponin I (cTnI) levels was noted on the 4th (p=0,04) and on the 7th day (p=0,0009) in MICAD patients. A significant predominance of the volume (p=0,01) and burden (p=0,004) of low-density plaques was revealed in the MICAD group compared to MINOCA. In addition, MICAD patients had significantly increased values of the total atherosclerotic burden (p=0,01) and the total burden of the soft tissue component of plaques (p=0,04). A significant correlation was found between the plaque volume with cTnI on day 7 (ρ=0,52, p<0,05) and the plaque burden with cTnI on day 7 (ρ=0,43, p<0,05).Conclusion. According to CTCA, the soft tissue component of plaques is associated with coronary atherosclerosis severity and myocardial damage in patients with MI. Soft tissue burden is a predictor of more severe myocardial damage, according to the cardiac biomarker data.

Introduction: Nowadays, coronary computed tomography angiography (CCTA) is a well-established method for identification of coronary artery disease (CAD) in patients with low pre-test probability. Most of these patients have non-obstructive CAD (NOCAD) and microvascular dysfunction. However, the data about the relationships between coronary plaque composition and the values of myocardial blood flow (MBF) and myocardial flow reserve (MFR) is lacking. The purpose of the study is to assess the relationships between quantitative CCTA variables and dynamic CZT SPECT in NOCAD patients.

Aim. To study the relationship between the coronary atherosclerosis involvement area and ischemia severity in terms of the consistency of dynamic single-photon emission computed tomography (SPECT) and myocardial perfusion scintigraphy (MPS) data with coronary angiography in patients with multivessel coronary artery (CAD) disease.Material and methods. The study included 327 patients with suspected or confirmed coronary artery disease (CAD), who previously underwent dynamic SPECT, MPS and invasive or computed tomography coronary angiography. Based on the data on coronary artery (CA) involvement, patients were selected: 1) with multivessel CAD (n=171), 2) with single-vessel CAD (n=71) and 3) non-obstructive CAD (n=85). Based on the MPS data, the presence and impaired perfusion area at rest and during the stress test, as well as the degree of their discrepancy were assessed: summed stress score (SSS), summed rest score (SRS) and summed difference score (SDS). The values of myocardial blood flow (MF) and MF reserve (MFR) were assessed using dynamic myocardial SPECT.Results. Standard MPS indices did not differ between the groups with non-obstructive, single-vessel and multivessel CAD as follows: 2,0 (0,0; 4,0) vs 5,0 (2,0; 7,0) vs 5,0 (3,0; 9,0) — SSS; 0,0 (0,0; 1,0) vs 3,0 (0,0; 5,0) vs 2,0 (0,0; 4,0) — SRS; 2,0 (0,0; 3,0) vs 3,0 (1,0; 6,0) vs 2,0 (0,0; 5,0) — SDS, respectively. The transient ischemic dilation did not differ between the study groups.Dynamic SPECT revealed a decrease (p<0,01) in global stress MF and MFR in patients with multivessel CAD compared to groups with non-obstructive and isolated single-vessel atherosclerosis: 1,07 (0,69; 1,49) vs 1,46 (1,08; 1,88) vs 1,48 (0,93; 1,89); 1,64 (1,16; 2,33) vs 2,28 (1,52; 2,93) vs 2,36 (1,58; 3,07), respectively.Net Reclassification analysis showed that MFR allows for correct reclassification of a significant proportion of patients with CAD compared to MPS (NRI=0,31, p=0,001).Conclusion. Dynamic myocardial SPECT is an adequate tool for assessing the ischemia volume in patients with extensive coronary involvement, and global MFR can be considered as one of the selection criteria for myocardial revascularization. The results obtained in this study require further study.

Aim. To study the relationship of coronary microvascular dysfunction (CMD) with the levels of pro- and anti-inflammatory biomarkers in patients with preserved ejection fraction (LVEF) and non-obstructive coronary artery disease (CAD). Material and methods . The study included 118 patients (70 men, mean age, 62,0 [58,0; 69,0] years) with preserved LVEF (62 [59; 64] %) and non-obstructive CAD. Serum levels of N-terminal pro-brain natriuretic peptide (NT-proBNP), high-sensitivity C-reactive protein (hsCRP), interleukin-1β, 6, and 10 were assessed initially by enzyme immunoassay. Coronary flow reserve (CFR) was assessed by dynamic single photon emission computed tomography. CFR ≤2 was a CMD marker. Results. Patients were divided into groups depending on CMD presence: group 1 included patients with CMD (n=45), and group 2 was the control group and included patients without CMD (n=73). HsCRP concentrations were 1,8 times higher (p=0,011) in group 1 compared to group 2. Interleukin-6 levels did not differ significantly between groups (p=0,842), while interleukin-10 concentrations were lower by 21,7 % (p=0,048), and interleukin-1β was 2,7 times higher (p=0,046) in group 1 compared to group 2. According to ROC analysis, hsCRP concentration ≥4,8 g/l (AUC=0,655; p=0,012), and NT-proBNP ≥950,6 pg/ml (AUC=0,792; p<0,001) were identified as markers associated with CMD in patients with non-obstructive CAD, while levels of interleukin-1β, 6 and 10 showed no diagnostic significance. Multivariate regression analysis showed that diastolic dysfunction (odds ratio, 3,27; 95% confidence interval, 2,26-5,64; p<0,001) and NT-proBNP ≥950,6 pg/ml (odds ratio, 2,07; 95% confidence interval, 1,56-4,12; p=0,023) were independent factors associated with CMD. Conclusion . We established that in patients with non-obstructive CAD, the pre­sence of CMD is associated with a higher expression of pro-inflammatory markers and a decrease in the expression of an anti-inflammatory marker, which may confirm the fact that chronic inflammation is one of CMD pathogenesis links.

(1) Background: The objective of this study was to determine the optimal post-processing model for dynamic cadmium–zinc–telluride single-photon emission computed tomography (CZT-SPECT). (2) Methods: A total of 235 patients who underwent diagnostic invasive coronary angiography within three months of the SPECT and those who had coronary computed tomography angiography (CCTA) before SPECT (within 3 months) were enrolled in this study. Each SPECT study was processed to obtain global and regional stress myocardial blood flow (sMBF), rest-MBF (rMBF), myocardial flow reserve (MFR) and flow difference (FD) estimates obtained with 1-tissue-compartment (1TCM) and net retention (NR) modes, both with and without attenuation correction. (3) Results: The use of AC led to significantly higher sMBF, rMBF and DF values obtained by 1TCM compared those values derived by 1TCM with NAC; the lowest values of stress MBF and rest MBF were obtained by 1TCM_NAC. The resting flow, MFR and DF were significantly (p < 0.005) higher in the AC model than in NAC. All quantitative variables were significantly (p < 0.05) higher in NR_NAC than in the 1TC_NAC model. Finally, sMBF, rMBF and FD showed significantly (p < 0.05) higher values by using 1TMC_AC compared to NR_AC. (4) Conclusions: We suggested that 1-compartment and net retention models correctly reflect coronary microcirculation and can be used for clinical practice for evaluating quantitative myocardial perfusion by dynamic SPECT. Attenuation correction is an important step in post-processing dynamic SPECT data, which increases the consistency and diagnostic accuracy of models.

In a multifactorial vegetation experiment, the effect of the composition and properties of soils and soil-sandy substrates contaminated with various doses of copper acetate on the morphometric parameters of spring barley seedlings was studied. It has been shown that the germination and vigor of seed germination, as well as the length of roots, aboveground parts, and dry biomass of plants depend in a complex way on the concentration of Cu in soils and substrates, as well as their buffering capacity to heavy metals. The presence of two mechanisms of Cu influence on plant development was established: metabolic at СCu 500 mg/kg of soil and diffusion at СCu 500 mg/kg. Using methods of regression analysis on experimental data, a multiple regression equation was obtained that combines morphometric parameters of plants, concentration of Cu in the substrates, and the buffering capacity of soils to heavy metals. On its basis, in the coordinates of soil buffering capacity – Cu concentration, a curve of values f the maximum permissible concentration of Cu in soils in the concentration range from 17 to 2047 mg/kg. It makes the possibility to separate the zone of permissible development of barley plants (reduction of morphometric parameters by no more than 15%) from the zone of exceeding the accepted value of maximum permissible concentration of Cu. Thus, maximum permissible concentration of Cu is considered not as a fixed value, but as a function of Cu concentration, soil buffering capacity, and plant species.

Background and Aims: To study the role of autonomic regulation of cardiac activity in patients with non-obstructive coronary artery disease (CAD) depending on the presence of heart failure with preserved ejection fraction (HFpEF). Methods: Group 1 included 48 patients with newly diagnosed HFpEF, group 2-17 patients without HFpEF. Non-obstructive CAD was confirmed by computed coronary angiography. NT-proBNP concentrations were determined by ELISA. Heart rate variability was assessed by 24-hour ECG monitoring. LV function parameters were assessed using echocardiography. Results: SDANN correlated with myocardial stress in diastole (r=0.345; p=0.006), and SDNNidx correlated with cardiovascular resistance (r=0.301; r=0.045) and E/e' (r=0.256; r=0.032) (Fig.1). In group 1, SDANN values (p=0.006) were 13.1% lower than in group 2. In group 1, SDNNidx values (p=0.012) were 14.8% higher than in patients of group 2. At night, group 1 showed a decrease in rMSSD by 42.5% (p=0.007) compared with group 2. In group 1 pNN50% values were 2.6 (1.7; 11.5), and in group 2 - 14.6 (6.2; 67.5) ms (p=0.009) (Fig.2). Based on ROC analysis, SDNNidx ≤49 ms (AUS=0.768; p=0.012) and pNN50 ≤5 ms (AUS=0.777; p=0.007) were defined as threshold values associated with the presence of HFpEF in patients with non-obstructive coronary artery disease (Fig.3). Conclusions: Patients with non-obstructive CAD and HFpEF showed a decrease in parasympathetic effects on the heart at night with a parallel increase in the activity of the sympathoadrenal nervous system. SDNNidx and pNN50 values can be used as a marker for diagnosing HFpEF. Funding: Russian Science Foundation No. 22-25-20019 https://rscf.ru/project/22-25-20019/ and funds from the Administration of Tomsk Region”

Aim. To reveal the association between disorders of myocardial blood flow and reserve, according to dynamic single photon emission computed tomography (SPECT), with risk factors for cardiovascular diseases (CVD) in patients with nonobstructive coronary artery disease (CAD).Material and methods. The study included patients with suspected stable nonobstructive (<50%) CAD. Based on the survey data, anamnesis, out- and in-patient medical records, we analyzed main CVD risk factors. All patients underwent dynamic myocardial SPECT and analysis of blood lipid profile in vitro. Depending on myocardial flow reserve (MFR), two groups were formed: 1. With reduced MFR <2,0 (rMFR); 2. With normal MFR ≥2,0 (nMFR).Results. The study included 47 patients divided into 2 following groups: the rMFR group consisted of 24 patients (15 men, age 56,3±9,1 years), the nMFR group — 23 patients (13 men, age 58,4±10,7 years). There was no significant difference in prevalence of CVD risk factors in groups. However, dyslipidemia was detected more often in rMFR patients (p=0,053): 58% vs 30%, respectively. In patients with rMFR, there were significantly higher levels of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C). Correlation analysis revealed significant negative inverse relationships between MFR values with TC (ρ=-0,36, p=0,01) and LDL-C (ρ=-0,38, p=0,009). According to univariate logistic regression, significant predictors of reduced MFR were TC (odds ratio (OR), 2,32; 95% confidence interval (CI), 1,17-4,59; p=0,01) and LDL-C (OR, 2,16; 95% CI, 1,04-4,51; p=0,04). According to a stepwise multivariate logistic regression analysis, only TC was an independent predictor of a decrease in MFR (OR, 2,32; 95% CI, 1,17-4,59; p=0,02).Conclusion. MFR, determined by dynamic SPECT, is associated with TC and LDL-C levels. TC level is an independent predictor of a decrease in MFR.

Aim. To assess the development of adverse cardiovascular events in patients with non-obstructive coronary artery disease (CAD) and coronary microvascular dysfunction (CMD), identified by dynamic myocardial single-photon emission computed tomography (SPECT), during 12-month follow-up compared with patients without CMD.Material and methods. The study included 118 patients (70 men, mean age, 62,0 [58,0; 69,0] years) with preserved ejection fraction (62 [59; 64] %) and non-obstructive CAD. Serum levels of the N-terminal pro-brain natriuretic peptide were assessed at baseline by enzyme immunoassay. Coronary flow reserve (CFR) was assessed by dynamic SPECT. CFR ≤2 was a CMD marker.Results. Six patients discontinued participation in the study due to loss of contact with them, while the rest were divided into groups depending on CMD presence: group 1 included patients with CMD (CFR ≤2; n=42), and group 2 was the control group and included patients without CMD (CFR >2; n=70). Within 12-month follow-up, 25 patients reported adverse events. According to Kaplan-Meier analysis, the prevalence of adverse cardiovascular events was higher in patients with CMD (45,2%, n=19) than in patients without it (8,6%, n=6) (p<0,001). Multivariate regression analysis showed that the presence of CMD (odds ratio (OR), 2,42; 95% confidence interval (CI), 1,26-5,85; p<0,001) and diastolic dysfunction (OR, 3,27; 95% CI, 2,26-5,64; p<0,001) were independent predictors of poor outcomes. The combination of CMD with diastolic dysfunction more than 5 times increased the risk of adverse events (OR, 5,18; 95% CI, 3,61-11,84; p<0,001).Conclusion. We found that in patients with non-obstructive CAD, the presence of CMD, identified by dynamic myocardial SPECT, was associated with a higher risk of adverse cardiovascular events within 12-month follow-up period than in patients without CMD. At the same time, the combination of CMD with diastolic dysfunction more than 5 times increased the risk of adverse outcomes.

(1) Background: The results of the international studies support the assumption that coronary microvascular dysfunction (CMD) occurs significantly more often than previously identified and is associated with adverse outcomes. However, there is a lack of the accurate comprehension of its pathophysiology. The objectives of this study were to evaluate the clinical and instrumental features of CMD and to assess its prognostic value during 12 months of follow-up period. (2) Methods: A total of 118 patients with non-obstructive coronary artery disease (CAD) and preserved LV ejection fraction (62 [59; 64]%) were enrolled in the study. Serum levels of biomarkers were analyzed by enzyme-linked immunoassay. CMD was defined as the reduced myocardial flow reserve (MFR) ≤ 2 obtained by dynamic CZT-SPECT. Two-dimensional transthoracic echocardiography with evaluation of LV diastolic dysfunction was performed baseline. (3) Results: Patients were divided into groups depending on the presence of CMD: CMD+ group (MFR ≤ 2; n = 45), and CMD− group (MFR > 2; n = 73). In CMD+ group, the severity of diastolic dysfunction, the levels of biomarkers of fibrosis and inflammation were higher than in CMD− group. Multivariate regression analysis showed that the presence of diastolic dysfunction (OR 3.27; 95% CI 2.26–5.64; p < 0.001), the hyperexpression of NT-proBNP ≥ 760.5 pg/mL (OR 1.67; 95% CI 1.12–4.15; p = 0.021) and soluble ST2 ≥ 31.4 ng/mL (OR 1.37; 95% 1.08–2.98; p = 0.015) were independent factors associated with CMD. Kaplan–Meier analysis showed that a rate of the adverse outcomes was significantly (p < 0.001) higher in patients with CMD (45.2%, n = 19) than in patients without it (8.6%, n = 6). (4) Conclusions: Our data suggest that the presence of CMD was associated with the severe diastolic dysfunction and hyperexpression of the biomarkers of fibrosis and inflammation. Patients with CMD had higher rate of the adverse outcomes than those without it.

X-ray computed tomography coronary angiography (CTCA) is a current method for diagnosing ischemic heart disease. Although this method has a high specificity and a negative predictive value in diagnosing coronary obstructions, there are limitations in determining the hemodynamic significance of the stenosis. Extensive use of noninvasive methods for evaluation of coronary hemodynamics, specifically evaluation of the fractional flow reserve (FFR) is limited due to its high cost and risks of complications. Mathematical modeling of coronary circulation and its reserve based on CTCA data is an up-to-date method that has been experimentally confirmed and clinically validated. This method showed a high diagnostic efficacy in several large studies that used the invasive determination of FFR as a << gold standard >>. This review addresses the current state of studies on mathematical modeling for fractional coronary reserve in patients with ischemic heart disease, as well as the limitations and prospects of this method.

Background. Over the past few years, scientific data have demonstrated that patients with non-obstructive coronary artery disease can have high risk for adverse cardiovascular events (ACE) despite the absence of severe coronary obstruction. From this point of view, some patients require special monitoring and treatment; we have to find new methods for stratification of the risk of ACE. Aims to study the association of coronary artery calcification (CCA) with indicators of myocardial blood flow (MBF) and myocardial flow reserve (MFR) in patients with non-obstructive coronary artery disease (CAD). Methods. The study included patients (n = 52) with non-obstructive CAD ( 50%), identified by CCTA. All patients received dynamic myocardial SPECT according to the two-day rest-stress protocol with the radiopharmaceutical agent 99mTc-methoxy-isobutyl-isotnitrile and the pharmacological stress-test (adenosine triphosphate 160 mcg/kg/min) to determine quantitative indicators of MBF and MFR. Depending on the calcium index (CI), three groups of patients were formed: 1 without CCA (CI = 0 Agatston units), 19 patients; 2 Mild CCA (CI = 1100 Agatston units), 21 patients; 3 Moderate CCA (CI = 101400 Agatston units), 12 patients. Results. The study included 52 patients (age 55.0 9.8 years, 36 men). The groups differed statistically significantly (p 0.05) in terms of quantitative scintigraphic parameters: stress-MBF, MFR and MBF. When analyzing the groups in pairs, it was found that stress-MBF and MBF were significantly lower in the group with moderate CCA compared to the group without CCA, and MFR was lower in the group with moderate CCA compared to the groups without CCA and with mild CCA. Correlation analysis revealed significant relationships between CI and scintigraphic parameters: stress-MBF ( = 0.46; p = 0.003), MFR ( = 0.48; p = 0.001), MBF ( = 0.48; p = 0.0008), SSS ( = 0.34; p = 0.02) and SDS ( = 0.28; p = 0.046). Conclusions. Even with non-obstructive CAD, identified by CCTA, there is a decrease in MBF and MFR inversely proportional to the level of CI, which can be considered as an early marker of impaired vasodilation reserve of the vascular wall, which develops in atherosclerosis of the coronary artery.