Aim To determine levels of markers for endothelial dysfunction and inflammation, endothelin-1, E-selectin, and tumor necrosis factor α (TNF-α) in patients with ischemic heart disease (IHD) and non-obstructive and obstructive coronary artery (CA) disease. Material and methods This study included 32 patients with verified IHD and non-obstructive (main group, n=19) and obstructive (comparison group, n=13) CA disease. Endothelial dysfunction was diagnosed by photoplethysmography and videocapillaroscopy. Serum concentrations of endothelin-1, E-selectin, and TNF- α were measured in all patients. Results Patients with non-obstructive CA disease showed a tendency towards more pronounced endothelial dysfunction (alternative stiffness index, 7.8 m /s [6.35; 9.08]; reflection index, 36.95 % [23.4; 52.65]; capillary density following reactive hyperemia, 54.33 cap /mm2 [48.92; 75.83]; capillary density following venous occlusion, 74.33 cap /mm2 [67.83; 93.00]) compared to the comparison group (alternative stiffness index, 9.05 m/s [7.08; 10.58]; reflection index, 28.25 % [23.35; 53.75]; capillary density following reactive hyperemia, 66.83 cap /mm2 [50.83; 78.67]; capillary density following venous occlusion, 87.0 cap /mm2 [77.58; 78.67]), although statistically significant differences were not found. Concentration of endothelin-1 was significantly higher in the IHD group with non-obstructive CA disease (0.45 ng/ml [0.28;0.65]) compared to patients with CA atherosclerotic stenosis (0.35 ng/ml [0.25; 0.38], p=0.035). Concentrations of E-selectin did not significantly differ between the groups (main group, 21.1 ng/ml [18.45; 35.03]; comparison group, 28.55 ng/ml [19.08; 35.01], p=0.29). In both groups, concentrations of TNF-α did not exceed the lower threshold of sensitivity (<2.3 pg/ml). Conclusion Endothelial dysfunction and increased endothelin-1 in patients with non-obstructive CA disease along with inflammation may additionally contribute to the pathogenesis of IHD in the absence of hemodynamically significant CA stenoses. Too low level of TNFα in both groups prevented us from using it as a diagnostic marker. Further study is needed that would include a greater number of patients and a search for alternative markers.

Aim        A comprehensive assessment of retinal microcirculation in patients with stable ischemic heart disease (IHD) exhibiting obstructive and non-obstructive coronary artery (CA) lesions. Materials and methods This observational comparative study included 35 patients with stable IHD, divided into those with CA obstructive lesions (n=25) and those with ischemia with non-obstructive coronary arteries (INOCA) (n=10). A control group consisted of 30 healthy volunteers with no cardiovascular risk factors. The groups were matched for age and body mass index. All participants underwent coronary angiography or CT coronary angiography. Tissue perfusion and the amplitude-frequency spectrum of blood flow fluctuations (endothelial component) were assessed via laser Doppler flowmetry (LDF) of the bulbar conjunctiva, and optical coherence tomography angiography (OCT-A) of the macular region was performed using the SOLIX platform (Optovue, USA). Results Compared to the control group, patients with INOCA exhibited significantly higher vascular resistance (σ) and coefficient of variation (Kv), indicating more pronounced perfusion fluctuations. Both obstructive IHD and INOCA groups showed reduced endothelial flow amplitudes, a marker of endothelial dysfunction. OCT-A revealed that while macular vessel density remained stable, all IHD patients had increased foveal avascular zone (FAZ) area and perimeter. Specifically, the FAZ area was more significantly enlarged in obstructive IHD, whereas the FAZ perimeter was greater in INOCA ( p <0.05). The left eye FAZ perimeter showed moderate diagnostic accuracy in differentiating stable IHD patients from healthy volunteers (AUC=0.632). Conclusion LDF of the bulbar conjunctiva effectively captures systemic vascular alterations in IHD and differentiates between obstructive and non-obstructive IHD. The integration of LDF and OCT-A provides a promising multimodal approach for the early detection of microvascular impairment, including in IHD patients.

The development of different phenotypes of coronary artery (CA) lesions is regulated via many various factors, such as pro-inflammatory agents, zinc-dependent endopeptidases, growth factors and circulating microRNAs (miRs). To evaluate the expression levels of miR-34a, miR-145 and miR-222, tumor necrosis factor α (TNF-α), matrix metalloproteinases (MMP-1, -9, -13 and -14) and vascular endothelial growth factor (VEGF) in patients with different phenotypes of coronary artery disease (CAD): ischemia/angina with non-obstructive coronary arteries (INOCA/ANOCA) and obstructive CAD (oCAD) compared with a control group. This cross-sectional observational study included 157 subjects with a verified CAD diagnosis (51 patients with INOCA, 76 patients with oCAD and 30 healthy volunteers). The expression of miR-34a, miR-145 and miR-222 (RT-PCR) and the levels of VEGF, TNF-α, MMP-1, MMP-9, MMP-13 and MMP-14 (ELISA) were estimated in plasma samples. A higher concentration of MMP-9 was found in oCAD-group samples compared to the INOCA/ANOCA group. The INOCA/ANOCA group was characterized by higher levels of TNF-α. Based on multivariate regression analysis, a mathematical model predicting the type of CA lesion was constructed. MiR-145 was the independent predictor of INOCA/ANOCA (p = 0.006). Changes in concentrations of MMP-9 and MMP-14 were found in both investigated CAD groups, with MMP-9 levels being significantly higher in obstructive CAD samples than in INOCA/ANOCA, which confirms the role of inflammation in the development of atherosclerosis. A multivariate regression analysis allowed us to achieve a model that can predict the phenotype of stable CAD, and MiR-145 can be assumed as an independent predictor of INOCA/ANOCA.

MicroRNAs and the WNT signaling cascade regulate the pathogenetic mechanisms of atherosclerotic coronary artery disease (CAD) development. Objective: To evaluate the expression of microRNAs (miR-21a, miR-145, and miR-221) and the role of the WNT signaling cascade (WNT1, WNT3a, WNT4, and WNT5a) in obstructive CAD and ischemia with no obstructive coronary arteries (INOCA). Method: The cross-sectional observational study comprised 94 subjects. The expression of miR-21a, miR-145, miR-221 (RT-PCR) and the protein levels of WNT1, WNT3a, WNT4, WNT5a, LRP6, and SIRT1 (ELISA) were estimated in the plasma of 20 patients with INOCA (66.5 [62.8; 71.2] years; 25% men), 44 patients with obstructive CAD (64.0 [56.5; 71,0] years; 63.6% men), and 30 healthy volunteers without risk factors for cardiovascular diseases (CVD). Results: Higher levels of WNT1 (0.189 [0.184; 0.193] ng/mL vs. 0.15 [0.15–0.16] ng/mL, p < 0.001) and WNT3a (0.227 [0.181; 0.252] vs. 0.115 [0.07; 0.16] p < 0.001) were found in plasma samples from patients with obstructive CAD, whereas the INOCA group was characterized by higher concentrations of WNT4 (0.345 [0.278; 0.492] ng/mL vs. 0.203 [0.112; 0.378] ng/mL, p = 0.025) and WNT5a (0.17 [0.16; 0.17] ng/mL vs. 0.01 [0.007; 0.018] ng/mL, p < 0.001). MiR-221 expression level was higher in all CAD groups compared to the control group (p < 0.001), whereas miR-21a was more highly expressed in the control group than in the obstructive (p = 0.012) and INOCA (p = 0.003) groups. Correlation analysis revealed associations of miR-21a expression with WNT1 (r = −0.32; p = 0.028) and SIRT1 (r = 0.399; p = 0.005) protein levels in all CAD groups. A positive correlation between miR-145 expression and the WNT4 protein level was observed in patients with obstructive CAD (r = 0.436; p = 0.016). Based on multivariate regression analysis, a mathematical model was constructed that predicts the type of coronary lesion. WNT3a and LRP6 were the independent predictors of INOCA (p < 0.001 and p = 0.002, respectively). Conclusions: Activation of the canonical cascade of WNT-β-catenin prevailed in patients with obstructive CAD, whereas in the INOCA and control groups, the activity of the non-canonical pathway was higher. It can be assumed that miR-21a has a negative effect on the formation of atherosclerotic CAD. Alternatively, miR-145 could be involved in the development of coronary artery obstruction, presumably through the regulation of the WNT4 protein. A mathematical model with WNT3a and LRP6 as predictors allows for the prediction of the type of coronary artery lesion.

Aim. To study the levels of fibrosis markers in patients with stable coronary artery disease (CAD) and various types of coronary artery (CA) lesions (obstructive and non-obstructive), to identify possible differences for diagnosing the types of coronary obstruction.Material and methods. The observational study included three groups of patients: with non-obstructive (main group, coronary artery stenosis <50%; n=20) and obstructive (comparison group, hemodynamically significant coronary artery stenosis according to the results of coronary angiography; n=20) CAD and healthy volunteers (control group; n=40). Transforming growth factor beta 1 (TGF-β1) and matrix metalloproteinase 9 (MMP-9) levels were measured in plasma by enzyme immunoassay. According to the results of echocardiography, all patients included in the study were divided into four groups depending on the type of myocardial remodeling.Results. TGF-β1 levels were significantly higher in patients with obstructive CAD (p=0.008) than in patients with non-obstructive CAD and healthy volunteers (p 0.05). There were no statistically significant differences in TGF-β1 levels depending on the type of left ventricular remodeling (p=0.139). The maximum level of MMP-9 was in the group with obstructive coronary disease and significantly differed from the main group (p <0.001) and the control group (p=0.04).Conclusio. The maximum levels of TGF-β1 and MMP-9 were found in the group with obstructive coronary artery disease. The levels of these biomarkers in the main group were statistically different from the values obtained in the control group. Thus, considering the pathogenesis of the development of non-obstructive CAD, the use of fibrosis markers TGF-β1 and MMP-9 may be promising for diagnosing the severity of CA obstruction.

Aim . To assess the levels of matrix metalloproteinases (MMP), vascular endothelial growth factor (VEGF), and miRNA-34a expression in patients with ischemic heart disease (IHD) and obstructive and nonobstructive coronary artery (CA) disease. Material and methods . This cross-sectional observational study included 64 patients with IHD (diagnosis verified by coronary angiography or multislice computed tomography coronary angiography), of which 33 (51.6%) were men aged 64.9±8.1 years. 20 patients had nonobstructive CA disease (stenosis <50%), and 44 had hemodynamically significant stenoses. The control group consisted of 30 healthy volunteers. MMP-1, -9, -13, and -14, miRNA-34a, and VEGF were measured in all patients. Results . The concentration of MMP-1 was significantly higher in patients with ischemia and nonobstructive CA disease (INOCAD) (p=0.016), and the concentration of MMP-9 was the highest in the group with obstructive CA disease (p<0.001). The concentrations of MMP-13 and MMP-14 did not differ significantly between the groups. The highest VEGF concentrations were observed in the INOCAD group (p<0.001). The expression of miRNA-34a significantly differed between the IHD groups with different types of CA disease and controls (p <0.001). Patients with hemodynamically significant stenosis showed moderate relationships between the concentrations of MMP-14 and VEGF (ρ=0.418; p=0.024), as well as between VEGF and miRNA-34a (ρ=0.425; p=0.022). Patients with INOCAD had a significant negative correlation between the concentrations of MMP-13 and VEGF (ρ= –0.659; p=0.003). Correlation analysis showed in all IHD patients a moderate relationship of the concentrations of MMP-1 and MMP-14 with VEGF (ρ=0.449; p=0.002 and p=0.341; p=0.019, respectively). According to ROC analysis, a MMP-9 concentration above 4.83 ng/ml can be a predictor for the presence of hemodynamically significant CA obstruction in IHD patients; a VEGF concentration higher than 27.23 pg/ml suggests the absence of hemodynamically significant CA stenosis. Conclusion . IHD patients with INOCAD had the greatest increase in MMP-1, whereas patients with obstructive CA disease had the highest level of MMP-9. According to our data, concentrations of MMP-9 and VEGF can be used to predict the degree of CA obstruction. The expression of miRNA-34a was significantly higher in IHD patients with INOCAD and CA obstruction than in the control group, which suggested a miRNA-34a contribution to the development and progression of coronary atherosclerosis. In the future, it may be possible to use this miRNA as a diagnostic marker for IHD.