Comparison of Non-Newtonian Models of One-Dimensional Hemodynamics

The paper is devoted to the comparison of different one-dimensional models of blood flow. In such models, the non-Newtonian property of blood is considered. It is demonstrated that for the large arteries, the small parameter is observed in the models, and the perturbation method can be used for the analytical solution. In the paper, the simplified nonlinear problem for the semi-infinite vessel with constant properties is solved analytically, and the solutions for different models are compared. The effects of the flattening of the velocity profile and hematocrit value on the deviation from the Newtonian model are investigated.

Fixed combination of ramipril and indapamide in patients with hypertension and non-alcoholic fatty liver disease: focus on the large arteries

Objective. To assess the effect of antihypertensive therapy with ramipril and indapamide on the elasticity of the vascular wall of the large arteries in relation to insulin resistance and chronic low-intensity inflammation in patients with hypertension (HTN) and non-alcoholic fatty liver disease (NAFLD). Design and methods. An open prospective controlled study was conducted: 30 patients with HTN stage I–II in combination with NAFLD (Fatty Liver Index (FLI) > 60) at the age of 45–65 years were included. Washout period was scheduled 5–7 days before the baseline examination, followed by the prescription of one of the fixed combinations of ramipril (2,5/5 mg/day) and indapamide (0,625/1,25 mg), depending on the required dosage (Konsilar-D 24 VERTEX AO, Russia) and were given recommendations on lifestyle changes and weight loss. A clinical examination was carried out, indicators of daily blood pressure (BP) monitoring and central aortic pressure (CAP), pulse wave velocity (PWV), lipid and carbohydrate metabolism, chronic low-intensity inflammation and the severity of insulin resistance before and after treatment were analyzed. Results. After 24-week therapy with a fixed combination of ramipril and indapamide at an average dosage of 4,04 ± 1,24 and 1,01 ± 0,31 mg, respectively, 100% of patients with HTN and NAFLD achieved target BP levels. According to 24-hour BP monitoring data, a significant decrease in systolic BP (SBP) and diastolic BP (DBP) was observed, both in the daytime (Δ12 mm Hg, р = 0,0001; Δ5,5 mm Hg, р = 0,0019, respectively), and at night (Δ13,5 mm Hg, р = 0,0006; Δ5,5 mm Hg, р = 0,0054, respectively). In addition, there was a significant decrease in CAP in the daytime (SBPao p = 0,0011, DBPao p = 0,0022) and night hours (SBPao p = 0,0015, DBPao p = 0,00124), and a statistically significant decrease in augmentation index (day p = 0,0460, night p = 0,0182). When evaluating clinical data and bioimpedance measurements, a decrease in waist circumference (p = 0,0000), hip circumference (p = 0,0001), the proportion of subcutaneous (p = 0,0134) and visceral (p = 0,0019) fat was found, which may indicate a decrease in the severity of visceral obesity. Also, during treatment, there is a decrease in the severity of insulin resistance (and the concentration of tumor necrosis factor alpha (TNF-α) (p < 0,0001) and CRP (p = 0,0002) in blood plasma. Finally, fixed combination of ramipril and indapamide led to a significant decrease in vascular stiffness (p = 0,0166) and a decrease in the proportion of patients with PWV paradoxical test (p = 0,0320). Correlation analysis showed that increased stiffness of the large arteries in patients with HTN and NAFLD is closely related to insulin resistance and lipid metabolism. At the same time, after 24-week therapy by a fixed combination of ramipril and indapamide, a decrease in the vascular stiffness in patients with HTN and NAFLD significantly correlated with the TNF-α concentration. Conclusions. A 24-week therapy by the fixed combination of ramipril and indapamide iin patients with HTN and NAFLD is associated with the persistent decrease in BP and CAP, both during the day and at night. There was a decrease in the vascular rigidity in muscular arteries. The treatment and recommendations for changing the lifestyle are associated with the decrease in the severity of abdominal obesity and insulin resistance, as well as the decrease in the severity of low-intensity systemic inflammation in patients with HTN and NAFLD, and a significant correlation was established between a decrease in TNF-α and an increase in the vascular elasticity of muscle and elastic type arteries.

MO473INTERACTION OF SCLEROSTIN AND OSTEOPROTHERIN IN THE DEVELOPMENT OF VASCULAR CALCIFICATIONS AT STAGE 3-5 OF CHRONIC KIDNEY DISEASE

Background and Aims: Background and Aims: . Vascular calcification (VC) due to bone-mineral metabolism disorders is a predictor of high cardiovascular mortality in patients with late-stage chronic kidney disease (CKD) . The established bone-vascular axis in CKD, which relates to interactions between changes in the bone and vascular systems that have similar mechanisms, allows bone metabolism inhibitors to act as potential risk factors for VC. Morphogenetic protein osteoprotegerin (OPG) and glycoprotein sclerostin are opposite inhibitors of bone metabolism: OPG inhibits osteoclastogenesis, sclerostin has an inhibitory effect on osteoblastogenesis. Although both proteins are recognized as high-risk factors for remodeling the heart and large arteries in patients with CKD, the mechanisms and possibilities for correcting these changes are not fully clear. of the study was to investigate the mechanisms of the relationship between OPG and sclerostin in the development of cardiovascular complications due to calcification of the aorta and large arteries in the late stages of CKD. Method: Method The cross-sectional study included 105 patients with stage 3-5 CKD [49 men; 64.0 (23.0-76.0)years]. The glomerular filtration rate determined using the CKD-EPI equation was 38.4 (8.6–92.3) ml / min / 1.73 m2. The general clinical examination included assessment of hematopoiesis (hemoglobin, hematocrit, ferritin and transferrin), determination of total protein and albumin levels, cholesterol, electrolytes (sodium, potassium) in the blood, and indicators of nitrogen metabolism (creatinine, urea). Parameters of bone-mineral metabolism – parathyroid hormone (PTH), calcium, phosphorus, alkaline phosphatase of blood serum-were evaluated. The level of morphogenetic protein OPG and glycoprotein sclerostin was determined using commercial ELISA kit from Biomedica (Austria) by enzyme immunoassay. The morphofunctional features of the aorta and large arteries were studied by duplex scanning using the Doppler effect. We determined the peak systolic velocity of blood flow in the aortic arch (Vps-peak systolic velocity) , which indirectly indicates the state of the aortic wall and its lumen. Echocardiography with Doppler imaging was performed on the "ALOKA 4000" device. The LV myocardial mass index (LVMI), LV hypertrophy variants, LV systolic and diastolic function were determined. Results Cardiovascular damage, which manifests itself in the form of various variants of left ventricular hypertrophy, aortic rigidity, arteriosclerosis and vascular calcification, and directly correlated with the severity of renal failure, was detected in 86% of the examined patients with stage 3-5 CKD. The level of OPG and sclerostin in the blood serum increased with the progression of renal failure from the 3rd to the 5th. The main associations with Vps changes were high OPG levels [OR = 2.39 95% confidence interval (95% CI) (1.34–4.86) for levels ranging from 5.98 to 9.26 pmol / L and OR = 5.54 95% CI (2.64–13.5) for levels ≥9.26 pmol / L; P &lt;0.0001] and high sclerostin levels [OR = 2.64 95% CI (1.42–5.16) for levels ranging from 0.744 to 1.211 ng / ml and OR = 3.69 95% CI (1.76–7.31) for a level ≥1.211 ng / ml; P = 0.0001]. Thus, the logistic regression model showed that the risk of aortic calcification was significantly increased when both OPG (≥5.98 pmol / L) and sclerostin (≥0.744 ng / ml) levels were high [ uncorrected model: OR = 11.93 (4.54–25.2); P &lt;0.0001; on the model adjusted for generally recognized cardiovascular disease risk factors: OR= 5.55 (1.43–1914); P = 0.02]. Conclusion The results suggest that bone metabolism inhibitors, OPG and sclerostin, are independently associated with aortic calcification with potential additive effects in patients with stage 3-5 CKD. The risk of vascular calcification was significantly increased when OPG and sclerostin levels were high

Takayasu arteritis

Takayasu arteritis is a rare form of the vasculitis of large arteries. It is a disease difficult to diagnose and treat, often unpredictable in terms of outcome and life-treatening. Despite its low prevalence, Takayasu arteritis deserves close attention for therapists, cardiologists, rheumatologists and angiosurgeons. This article presents classifications, features of the clinical course of the disease, possibilities of the visualization diagnosis of the lesions of arteries, assessment of the disease activity. The issues of the contemporary drug therapy, interventional and surgical treatment methods and complications of the disease are presented.