No abstract

Objective:to determine the cut-off of natriuretic peptide for optimization dyagnosis heart failure in comorbid patients with thyrotoxicosis, to assess the dynamics of this indicator during therapy.Materials and methods:111 patients (58,3±5,6 years) were divided into 4 groups. Te main group consisted of 25 patients with CHD, CHF II-III FC and thyrotoxicosis; the 1st group of comparison - 30 patients with CHD and CHF II-III FC, without thyrotoxicosis; the 2nd group — 30 patients with thyrotoxicosis without CHD, the 3rd group - 26 patients with thyrotoxicosis and CHD, with no signs of CHF. Te fnding of thyroid gland, the level of NT-proBNP was estimated at baseline and afer 6 months therapy. A new cut-off NT-proBNP for the diagnosis of CHF in comorbid patients was calculated by using ROC analysis.Results:the high concentration of NT-proBNP was detected in all patients (more then 125 pg/ml), in the 2nd comparison group — 225.5 (180.1, 376.1) pg/ml. Te NT-proBNP values in the patients of the 1st and 3rd comparison groups did not differ signifcantly. Te highest level of NT-proBNP was detected in the main group — 712.1 (434.3, 893.9) pg/ml. A cut-off of this marker for screening CHF in comorbid patients with CHD and thyrotoxicosis was calculated - 556.4 pg/ml (a sensitivity of 72 %, a specifcity of 100 %, an accuracy of 87.2 % (p <0.001)). Afer 6 months therapy in the 2nd comparison group the level of NT-proBNP decreased by 74 % (р<0,0001) and has reached the normal value (64,6 (42,2;76,3)); in the main group the level decreased by 43% and was 406,7 (309,1; 498,6) pg/ml.Conclusions:the patients of all groups showed an increased concentration of NT-proBNP. Te highest level of NT-proBNP was observed in the group of patients with CHF by CHD and thyrotoxicosis. Te level of NT-proBNP was determined - 556.4 pg/ml, which allows us to diagnose CHF in patients with a combination of CHD and thyrotoxicosis.

Thus, using a rank correlation analysis, a preliminary analysis of the relationship between the increase / decrease in blood creatinine, blood urea, GFR (Cockcroft-Gault) and GFR (CKD-EPI) after coronary angiography with vascular events was performed. A KaplanMeier survival analysis demonstrated the statistically significant effect of contrast-induced nephropathy on the risk of death from myocardial infarction in patients with long-term acute coronary syndrome.

Цель. Оценить диагностическую значимость критериев хронической сердечной недостаточности (ХСН) и изучить особенности структурно-функционального ремоделирования левых отделов сердца у пациентов с ишемической болезнью сердца (ИБС) и тиреотоксикозом. Материал и методы. Обследовали 131 пациента в возрасте 45-65 лет, с ИБС, ХСН и/или тиреотоксикозом. Оценивали клиническое состояние больных и толерантность к физической нагрузке, определяли уровень N-концевого фрагмента предшественника мозгового натрийуретического пептида (NT-proBNP), выполняли Холтеровское мониторирование электрокардиограммы и эхокардиографическое исследование (ЭхоКГ) с допплерографией. Результаты. У пациентов с ИБС, ХСН и тиреотоксикозом чаще, чем у больных с ИБС и ХСН без тиреотоксикоза, определялись нарушения ритма сердца (фибрилляция предсердий, синусовая тахикардия, наджелудочковая экстрасистолия), более выраженный вегетативный дисбаланс с преобладанием активности симпатического звена вегетативной нервной системы. Выявлен повышенный уровень NТ-proBNP (>125 пг/мл) как у пациентов с ХСН, так и у пациентов с тиреотоксикозом, независимо от наличия сердечно-сосудис тых заболеваний. Концентрация NT-proBNP у больных с ИБС и тиреотоксикозом без ХСН превышала пороговое значение в 2,8 раза (р=0,001). Наиболее высокий уровень NT-proBNP у пациентов с ИБС, ХСН и тиреотоксикозом обусловлен влиянием на его секрецию не только ремоделирования левого желудочка (ЛЖ), но и гиперфункции щитовидной железы. Определено более высокое пороговое значение NT-proBNP (по результатам данного исследования-556,4 пг/мл) для диагностики ХСН с сохраненной и промежуточной фракцией выброса (ФВ) ЛЖ у пациентов с ИБС и тиреотоксикозом. При анализе параметров ЭхоКГ у больных с ИБС, ХСН и тиреотоксикозом выявлены достоверно более низкие значения линейных и объемных показателей ЛЖ, диастолическая дисфункция ЛЖ I типа в 100% случаев, промежуточный тип фракции выброса ЛЖ (48%), более частая встречаемость концентрической гипертрофии ЛЖ (84% случаев). Заключение. Для диагностики СН у пациентов с ИБС и тиреотоксикозом необходимо учитывать особенности клинической картины, показателей вариабельности сердечного ритма, ремоделирования ЛЖ, использовать более высокий пороговый уровень NT-proBNP. Ключевые слова: хроническая сердечная недостаточность, ишемическая болезнь сердца, тиреотоксикоз, вегетативный дисбаланс, пороговый уровень NT-proBNP, ремоделирование левого желудочка. Конфликт интересов: не заявлен. 1 ФГБОУ ВО Ростовский государственный медицинский университет Минздрава России, Ростов-на-Дону; 2 ГБУ РО Ростовская областная клиническая больница, Ростов-на-Дону, Россия.

ev UDC 669.15The paper addresses the action of a high-temperature hydrogen-containing fluid on mechanical properties of a low-alloy carbon hypopearlitic steel 09G2S which is used for the manufacture of a gasoline-producing reactor vessel for a catalytic reformer unit. The vessel metal had 180,000 running hours at a hydrogen-containing fluid temperature 280°C and pressure 4.0 MPa. It is demonstrated that a long-term operation of the material in contact with gaseous hydrogen has caused its natural ageing. Further hydrogen saturation of test specimens at 580°C and 10 MPa for 17 h has resulted in a so-called hydrogen-induced strain hardening of the material. The influence of gaseous hydrogen on the state of carbide phases in the base metal and weld is studied by the x-ray spectrum analysis and nuclear gamma resonance method. The amount of a carbide phase (cementite) in steel has been found to grow due to natural ageing at elevated temperatures. The high-temperature hydrogen saturation makes the cementite decomposition process more intensive, and no cementite recovery occurs even when the material is heated up to 580°C.Introduction. The interaction between commercial steels and hydrogen was the subject of numerous studies [1][2][3][4][5][6][7] which have demonstrated that the physicochemical action of hydrogen on the metal, which is accompanied by chemical interaction of the gas with the alloy's individual components and phases, tend to cause irreversible microstructural alterations in the metal. Also, a unique effect of the structural factor on the behavior of alloys in a hydrogen medium was noted more than once. Archakov [5] substantiates the conclusion that the hydrogen resistance of steels depends on the nature of the carbide phase that governs the metal-carbon interatomic bond strength as well as on the presence of other elements dissolved in the phase.The processes of carbide precipitation and growth are known to depend on the structure. Due to the difference in their rates at the grain boundaries and in the matrix (the maximum rate is at the grain boundaries and minimum one in the matrix precipitates), carbides are redistributed between the body and boundaries of the grains, predominantly at the grain boundaries. The concentration of carbides at the grain boundaries or their accumulation inside a grain has been found to promote localization of absorbed hydrogen, which in turn impairs the microstructure stability, degradation of properties and local fracture in the material. Specifically, the researchers [4, 5] point out a deteriorated cementite stability (due to the domination of covalent bond and a low concentration of electron gas in this iron-carbon compound) and the possibility of dissolution of less stable carbides under certain conditions: the cementite decomposition at elevated hydrogen temperatures and pressures, which is accompanied by the methane formation and steel decarburization.Considering that the process equipment of oil refinery facilities has to work under the conditions of hydrogenation proce...