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 4^th (p=0,04) and on the 7^th 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.

Background: Studies have demonstrated that patients with non-obstructive coronary artery disease (NOCAD) have an increased risk of myocardial infarction and all-cause mortality, particularly due to coronary microvascular dysfunction (CMD). Moreover, the features of atherosclerotic plaque can affect myocardial blood flow (MBF); however, data on these findings remain limited. Therefore, this study aimed to assess the impact of quantitative coronary computed tomography angiography (CCTA)-derived atherosclerotic plaque features on myocardial perfusion and MBF in NOCAD patients measured using dynamic cadmium–zinc–telluride single-photon emission computed tomography (CZT-SPECT). Methods: Based on the CCTA results, a total of 49 NOCAD patients (stenosis <50%, 29 men, mean age 57.4 ± 9.0 years) were included in the study. In addition to estimating stenosis severity, the plaque volume (mm3) and burden (%) were measured using the coronary bed and separately by structural components (non-calcified, soft-tissue, fibrous, calcified). All patients underwent dynamic CZT-SPECT to assess stress and resting MBF and myocardial flow reserve (MFR). Results: Based on the MFR values, patients were divided into two groups: Group 1 consisted of patients with reduced MFR (<2.0, n = 20), and Group 2 consisted of those with normal MFR (≥2.0, n = 29). Not all patients had severe myocardial perfusion abnormalities, as determined by standard myocardial perfusion imaging indexes. Analysis of the CCTA data demonstrated that small volumes and burdens of atherosclerotic plaques were characteristic of patients. Stress was significantly correlated with total plaque volume (Spearman's rank correlation coefficient (ρ) = –0.402) and burden (ρ = –0.374), as well as non-calcified plaque volume (ρ = –0.341) and burden (ρ = –0.314). Rest significantly correlated with total plaque volume (ρ = –0.504) and burden (ρ = –0.432), and non-calcified plaque volume (ρ = –0.471) and burden (ρ = –0.433). Meanwhile, MFR and standard indexes of myocardial perfusion impairment did not exhibit significant associations with quantitative CCTA parameters. Multivariate logistic regression analysis revealed that only total plaque volume (odds ratio 1.01; 95% confidence interval 1.005–1.030; p < 0.001) was an independent predictor of reduced stress-related MBF of less than 1.5 mL/min/g. Conclusions: Total plaque volume, derived from quantitative CCTA data, represents an independent predictor of reduced stress-related MBF of less than 1.5 mL/min/g, as obtained using dynamic CZT-SPECT, even in the absence of obstructive coronary artery disease (CAD).

Background/Objectives: Coronary computed tomography angiography (CCTA) is a modern method for assessing the total burden of atherosclerotic lesions. The perivascular fat attenuation index (PFAI) is a reliable predictor of major adverse cardiovascular events (MACE). Radiomics extracts substantially more information from images than visual assessment by radiologists. However, the relationships between quantitative parameters of coronary atherosclerosis, the PFAI, and radiomic features of pericoronary adipose tissue (PCAT) in patients with coronary artery disease (CAD) remain unclear. The study aimed to evaluate the associations between PCAT characteristics, including radiomic features, and quantitative parameters of coronary atherosclerosis in stable CAD patients. Methods: The study included 79 patients with stable CAD who underwent CCTA. The patients were divided into two groups: nonobstructive CAD (NOCAD, stenosis < 50%; n = 61) and obstructive CAD (OCAD, stenosis ≥ 50%; n = 18). The CCTA data were analyzed to quantify coronary atherosclerosis parameters (plaque volume and burden), the PFAI, PCAT volume, and radiomic features of PCAT in the proximal segments of major coronary arteries. Results: The study included 79 patients: NOCAD group = 61 patients (age 57.00 (50.00–65.00) years) and OCAD group = 18 patients (age 60.5 (55.75–65.75) years). The OCAD patients exhibited higher plaque volume and burden across all components. No significant between-group differences were observed in PFAI or PCAT volume for any vessel. However, 50% (46/92) of PCAT radiomic features in the proximal right coronary artery (RCA) differed significantly between groups, 42 of which were textural. The PFAI correlated most strongly with soft tissue (ST) plaque volume (ρ = −0.22), and burden (ρ = −0.21) of the soft tissue component of plaques (p < 0.001). The PCAT volume significantly correlated (p < 0.001) with plaque volume (ρ = 0.30) and with individual components—soft tissue (ρ = 0.30), fibrous–fatty (ρ = 0.27), fibrous (ρ = 0.30), calcified (ρ = 0.22), and non-calcified (ρ = 0.30)—as well as with the burden of the soft tissue component (ρ = 0.26). Conclusions: The radiomic features of RCA PCAT differed significantly between the NOCAD and OCAD groups. Quantitative coronary atherosclerosis parameters showed significant associations with the PCAT radiomic features in CAD patients, potentially serving as independent predictors of the MACE risk. In contrast, the PFAI values did not differ between groups and neither PFAI nor PCAT volume associated with atherosclerosis parameters.

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 evaluate the influence of epicardial adipose tissue (EAT) volume and density, based on computed tomography (CT) data, on the severity of myocardial injury assessed using cardiac biomarkers. Material and methods. The study included patients with newly diagnosed acute myocardial infarction (MI). All patients underwent invasive coronary angiography. Two following groups were formed: 1) MI with obstructive coronary artery disease (MICAD) (stenosis ≥50%); 2) MI with non-obstructive coronary arteries (MINOCA) (stenosis <50%). Cardiac biomarker levels (cardiac troponin I (cTnI), cardiac creatine phosphokinase (CPK-MB)) were determined at admission, 24 hours later, and on days 4 and 7. CT coronary angiography was performed on day 7 hospitalization. EAT volume and density were calculated using CT data. Results . The study included 31 patients as follows: 21 with MICAD (age 62 (56; 68) years) and 10 with MINOCA (age 68 (57; 79) years). MICAD patients had higher levels of cardiac biomarkers. Significant differences in EAT volume were found between MICAD and MINOCA patients (p<0,05). The median EAT volume in MICAD patients was greater than in MINOCA patients: 125 (69,4; 169) cm3 and 70,9 (62,4; 140) cm3, respectively. EAT density did not differ significantly as follows: MICAD -76,3 (-80; -71,6) HU, MINOCA -77,6 (-82,7; -73) HU. In the total sample, a significant nonparametric correlation was found between EAT volume and left ventricular end-diastolic mass (ρ=0,41; p=0,032), body surface area (ρ=0,55; p=0,002), and body mass index (ρ=0,54; p=0,003). EAT density negatively correlated with left ventricular enddiastolic mass (ρ=-0,39; p=0,041), body surface area (ρ=-0,54; p=0,003), and body mass index (ρ=-0,57; p=0,002). In the MINOCA group, negative correlations were obtained between biomarker levels and EAT volume, as well as significant positive correlations between CPK-MB at 24 h and cTnI on the 7th day with EAT density. EAT density was positively associated with elevated cTnI levels on day 7 (odds ratio (OR) 2,0, 95% confidence interval (CI) 1-3,5, p<0,05), CPK-MB at 24 h (OR 1,3, 95% CI 1-2,0, p<0,05), and CK-MB on day 4 (OR 2,0, 95% CI 1-3,5, p<0,05). Conclusion. In the acute period after acute MI, in patients with MINOCA, the EAT phenotype, characterized by a smaller volume and higher density, is associated with greater myocardial damage according to biomarker assessment, while in MICAD, the relationship between EAT properties and cardiac biomarkers is predominantly absent.

Aim. To evaluate the informative value of a 3D physicomathematical model of local hemodynamics based on coronary computed tomography angiography (CCTA) data for noninvasive determination of the functional significance of coronary artery (CA) stenosis. Material and methods . The study included 15 patients (mean age 57,6±8,9 years) with stable coronary artery disease (CAD). All patients underwent CCTA, and 9 patients underwent myocardial perfusion scintigraphy (MPS). Based on the CCTA images, 3D coronary artery models were constructed, in which fractional flow reserve (CT-FFR) was calculated at rest and during simulated hyperemia using COMSOL Multiphysics®. The modeling results were compared with the stenosis degree and ischemia signs based on the MPS data. Results . A total of 76 coronary vascular segments were analyzed. CT-FFR in simulated hyperemia values were significantly lower (p<0,001) in segments with stenosis ≥50% (0,53 [0,37-0,65]) and ≥70% (0,47 [0,34-0,55]) compared to non-obstructive lesions <50% (0,88 [0,83-0,96]) and <70% (0,87 [0,81-0,95]). A negative correlation was found between the stenosis degree and CT-FFR in simulated hyperemia (ρ=-0,485, p<0,05). ROC analysis demonstrated high diagnostic accuracy of CT-FFR in simulated hyperemia for stenoses ≥50% (AUC=0,9; sensitivity 93,7%; specificity 86,7%) and ≥70% (AUC=0,9; sensitivity 100%; specificity 83,6%). In vascular regions with perfusion defects according to MPS data, CT-FFR in simulated hyperemia were significantly lower (0,49±0,21 vs 0,82±0,18, p<0,001). Logistic analysis showed that a decrease in CTFFR in simulated hyperemia ≤0,68 was associated with an increased odds of regional ischemia (odds ratio 0,497; 95% confidence interval 0,33-0,73; p<0,001). Conclusion. The pilot study results confirm that the three-dimensional CT-FFR model, based on CCTA, is highly informative for assessing the anatomical and functional significance of coronary artery stenoses and can be used for non-invasive diagnosis of myocardial ischemia.