[Problematic aspects of pulmonary hypertension due to left heart disease: focus on combined postcapillary and precapillary pulmonary hypertension].

Рulmonary hypertension (PH) is a common complication of left heart diseases. In addition to a passive increase of pressure in the venous bed of the pulmonary circulation, leading to an increase of mean pulmonary pressure, signs of precapillary PH could be detected in some patients. Since 2013, a hemodynamic subtype of PH due to left heart diseases combined post/precapillary PH has been identified, with a more unfavorable prognosis and high mortality.

[Metilin Improves Сardiac Function in Rabbits With Chronic Heart Failure].

AIM: To study effects of intravenous infusion of a cardioprotective drug metilin, developed at the "National Medical Research Center of Cardiology" on indices of cardiac function in rabbits in vivo after prolonged administration of doxorubicin. MATERIALS AND METHODS: Animals of the experimental group were intravenously injected with doxorubicin (2 mg / kg once a week) for 8 weeks, animals of the control group received the same volume of saline. Myocardial damage was characterized by an increase in concentration of malondialdehyde (MDA), troponin (TnI) and MB-fraction of creatine kinase (CK-MB) in venous blood and by disturbances in the left ventricle (LV) structure at morphological examination. Metilin effects on cardiac function were assessed by echocardiography and LV catheterization by the Millar catheter tip pressure transducer. RESULTS: Doxorubicin administration led to a decrease of the body mass of animals, an increase of the plasma concentration of cardiac markers CK-MB and TnI, lipid peroxidation (LPO) product MDA in venous blood, and pronounced disturbances in the structure of LV fibers and microvessels. At the same time, a significant decrease of myocardial contractility indices was observed. Manifestations of this decrease were increase of the end-diastolic and end-systolic dimensions (EDD and ESD, respectively), and decreases in the shortening fraction and ejection fraction (SF and EF, respectively) compared to baseline values. These changes indicated development of chronic heart failure (CHF) in animals of the experimental group. Against this background, intravenous infusion of metilin significantly increased SF and EF, but did not affect the heart rate. Beneficial effects of metilin on the indices of cardiac contractility and relaxation were maintained after the infusion was stopped. Noteworthy, metilin exerted greater influence on cardiac function of rabbits with CHF compared to control animals that did not receive doxorubicin. CONCLUSION: The obtained results indicate the potential of metilin to reduce LV dysfunction during chemotherapy with doxorubicin.

[Contractile Function of Isolated Hearts With Preserved and Reduced Ejection Fraction In Vivo].

The aim of the study was comparison of contractile function of isolated hearts of rats with doxorubicin-induced myocardial injury which were tentatively divided according to the level of ejection fraction determined by echocardiography in vivo. After 4 weeks of doxorubicin administration (2 mg/kg subcutaneously once a week) about half of animals had normal (86±1 %) and the other half reduced (61±4 %) ejection fraction. The first group was defined as diastolic heart failure (DHF) and the other as systolic (SHF). The maximal pressure developed by the isolated heart in isovolumic mode was reduced in DHF by 13 %, and in SHF by 34 %. The relaxation index in both groups was lowed by 22-24 %. Both groups were characterized by a decline in the ability to raise developed pressure while increasing coronary perfusion pressure, as well as by the loss of the ability of coronary vessels to maintain a stable flow rate while increasing perfusion pressure. The hearts of control animals were able to raise the cardiac work index (the product of developed pressure and heart rate) during prolonged high frequency (7-9 Hz) stimulation, while the two groups treated with doxorubicin reduced the level of this index. The content of basic energy metabolites (ATP, phosphocreatine, creatine) in both groups was reduced by 20-38 %. The results showed that the hearts in DHF and SHF groups showed approximately the same level of reduction of the contractile function and energy metabolism, and hence their difference in vivo was probably due to varying degrees of mobilization of compensatory mechanisms.

Contractile Function of Isolated Hearts With Preserved and Reduced Ejection Fraction In Vivo.

The aim of the study was comparison of contractile function of isolated hearts of rats with doxorubicin-induced myocardial injury which were tentatively divided according to the level of ejection fraction determined by echocardiography in vivo. After 4 weeks of doxorubicin administration (2 mg/kg subcutaneously once a week) about half of animals had normal (86±1%) and the other half reduced (61±4%) ejection fraction. The first group was defined as diastolic heart failure (DHF) and the other as systolic (SHF). The maximal pressure developed by the isolated heart in isovolumic mode was reduced in DHF by 13%, and in SHF by 34%. The relaxation index in both groups was lowed by 22-24%. Both groups were characterized by a decline in the ability to raise developed pressure while increasing coronary perfusion pressure, as well as by the loss of the ability of coronary vessels to maintain a stable flow rate while increasing perfusion pressure. The hearts of control animals were able to raise the cardiac work index (the product of developed pressure and heart rate) during prolonged high frequency (7-9 Hz) stimulation, while the two groups treated with doxorubicin reduced the level of this index. The content of basic energy metabolites (ATP, phosphocreatine, creatine) in both groups was reduced by 20-38%. The results showed that the hearts in DHF and SHF groups showed approximately the same level of reduction of the contractile function and energy metabolism, and hence their difference in vivo was probably due to varying degrees of mobilization of compensatory mechanisms.

[Analysis of Urine Proteome in Patients With Postinfarction Cardiosclerosis Combined With Hypertensive Disease for Assessing Endothelial Dysfunction].

In our study urine protein composition of 18 healthy volunteers was compared with that of 18 patients with ischemic heart disease and concomitant hypertension. Liquid chromatography-mass-spectrometry (LC-MS) analysis of the second fraction of morning urine was carried out using nano-line high performance liquid chromatograph and hybrid mass spectrometer. The analysis revealed 23 proteins expressed in the endothelium, according to the information contained in the database Bgee, and 49 proteins, with direct functional link with the processes in the endothelium in the reconstruction of associative networks using ANDSystem program. Comparison of urine proteome of healthy people and patients with postinfarction cardiosclerosis revealed proteins specific for patients with cardiovascular disease. Thus, proteins vitronectin, syndecan-4, a histidine rich glycoprotein, endothelial protein C receptor, colony stimulating factor, cathepsin D and sekretogranin-1 may be considered as potential markers for cardiovascular diseases. Further research in this area should be conducted for clinical and experimental verification of these hypotheses.

[The Time Course of Formation Of Systolic Dysfunction of the Heart in Doxorubicin Cardiomyopathy].

The anthracycline-induced cardiomyopathy is a frequent and menacing complication of antitumor therapy leading to chronic heart failure. A study of the formation of heart failure can reveal early signs of the development of systolic dysfunction of the heart. In this work in rats we studied cardiac function at different duration of doxorubicin treatment, the most effective anthracycline antibiotic. Cumulative doses of doxorubicin were 8-20 mg/kg, and the term of study lasted from 6 to 20 weeks. The echocardiography and catheterization of the left ventricle (LV) have been use. The ejection fraction and other indicators of LV contractility decreased steadily with increasing dose and duration of the study, in parallel with rat survival. However, the cardiac output related to the unit of body weight, as well as diastolic LV size, remained at a level close to control within 8-10 weeks. Only after 20 weeks when the ejection fraction decreased from 81+/-1 to 49+/-4%, diastolic LV volume increased by 59%. Invasive indicators of myocardial contractility and relaxability significantly decreased by 11 and 19% after doxorubicin dose of 8 mg/kg, while time of preejection and time of systole increased by 18 and 10%. These changes progressed with increasing doses of doxorubicin. At each dose, the relaxation constant declined relatively deeper than contractility index by 8-25%. The results show that: 1) the gradual formation of cardiac insufficiency mobilizes a variety of compensatory mechanisms that retard cardiac dilatation; 2) the development of systolic dysfunction takes place with a predominantly violation of relaxation process; 3) an elongation of the preejection period and duration of systole may serve as noninvasive criteria for the formation of the systolic dysfunction.

[The Action of Apelin-12 and Its Analog on Hemodynamics and Cardiac Contractile Function of Rats With Isoproterenol-Induced Myocardial Lesion].

Introduction of isoproterenol (beta-adrenoreceptor agonist) into rats is one of the widespread experimental models of heart failure. It is caused by diffuse ischemic damage of cardiomyocytes, followed by development of substitutive fibrosis. Apelin is a natural regulator of the myocardial contractility. The effects of apelin molecule fragment, apelin-12 and its more stable synthetic analogue, apelin-12-2 on cardiac contractile function of rats with isoproterenol-induced myocardial lesion (IML) and control animals has been studied in this work using invasive (catheterization of the left ventricle) and non-invasive (echocardiography and impedansometry) methods. Infusion of both peptides was made by sequentially increasing rate from 0.5 to 50 µg/kg/min. In the control group, efficacy of apelin-12 was low while apelin-12-2 moderately but significantly increased indices of myocardial contractility and relaxability. These changes were more pronounced in rats with IML and, in addition, the heart rate and LV systolic pressure increased in this group. These results correlate well with echocardiographic studies which showed increases of LV end diastolic volume, stroke volume and ejection fraction by 17-38%. These alterations are probably due to improved Ca2+ transport in cardiomyocytes, as in experiments on isolated cardiomyocytes both apelins have facilitated and improved Ca2+ removal from myoplasma. The results allow to conclude that apelin-12-2 seems to be a promising candidate for further development as a therapeutic agent in heart failure.

[Complex study of the rat heart at isoproterenol damage].

Introduction of isoproterenol (an agonist of beta-adrenoreceptors) to rats is one of the widespread experimental models of cardiac failure. It is caused by damage of cardiomyocytes with the subsequent development of substitutive fibrosis. The purpose of the given work was the complex characteristic of cardiac function by means of invasive and noninvasive (echocardiography and impedansometry) methods of research. Isoproterenol was injected twice with a daily interval in dozes 85, 120, 150 or 180 mg/kg. Echocardiographic study of the heart in 2 weeks revealed obvious attributes of cardiac failure (left ventricular dilatation, lowered ejection fraction) in the groups which have received high cumulative dozes of isoproterenol (300-360 mg/kg). The catheterization of the left ventricle in these groups has shown raised enddiastolic pressure, decreased maximal rate of pressure development and fall, and also lowered indices of myocardial contractility and relaxability. In the groups which have received smaller isoproterenol dozes, apparent decrease in relaxability parameters (constants of isovolumic and auxovolumic relaxation) has been revealed at only slightly changed parameters of contractility. A strong correlation between echocardiographic and invasive parameters of myocardial contractility has been found. The phase analysis of the cardiac cycle has shown a lengthening of isometric phases of contraction and relaxation, as well as duration of ejection due to shortening duration of filling of both ventricles. Cardiomyocytes isolated from hearts with obvious cardiac failure responded to electrostimulation by arrhythmic contractions and also by much slowed and incomplete removal of free Ca++ from the myoplasm. Results allow to conclude that relatively smaller extent of myocardial damage is accompanied by decreased relaxability at slightly changed contractility, while at greater degree of damage both processes fail, but delay of relaxation still prevails.

[The study of hypotensive action of dinitrosyl-iron complex with glutathione containing drug oxacom in healthy volunteers].

On the basis of earlier executed studies of hypotensive effect of dinitrosyl iron complexes (DNIC) with glutathione, the drug has been created in industrial conditions named oxacom. Preliminary pharmacological studies of oxacom have not revealed negative qualities. The drug has been now tested in 14 healthy men in whom at single intravenous introduction it caused typical response - a decrease of diastolic as well as systolic arterial pressure on 24-27 mmHg through 3-4 min with subsequent very slow restoration in 8-10 hours. The heart rate after initial rise was quickly normalized. Echocardiography revealed unaltered cardiac output in spite of reduced cardiac filling by 28%. The multilateral analysis of clinical and biochemical data has revealed an absence of essential alterations which could lead to pathological consequences. The drug is recommended for carrying out of the second phase of clinical trial. The comparative study of the efficiency of hypotensive action of oxacom, S-nitrosoglutathione (GS-NO) and sodium nitrite (NO2) in rats has shown that the duration of effect was the greatest at oxacom action.

[Amount of circulating endothelium precursors in patients with stable angina of effort and patients with acute non-ST-elevation coronary syndrome].

AIM: To measure and compare the level of circulating precursors of endothelial cells in patients with acute coronary non-ST-elevation syndrome (NSTES), patients with stable effort angina (SEA) before coronary stenting and after it and persons with documented absence of coronary heart disease (CHD). MATERIAL AND METHODS: The trial included 19 patients with acute coronary NSTES, 20 patients with SEA and 14 patients free of CHD. Blood samples were stained with antibodies CD45-FITC (Becton Dickinson), CD34-PerCP (Becton Dickinson), KDR-PE (R&D systems). Count of cell populations was measured with flow cytofluorimetry (FACSCalibur (Becton Dickinson). RESULTS: SEA patients had the number of circulating cells CD34+ including hematopoietic cells and endothelial precursors (EP) two times lower versus that in the controls (0.650 +/- 0.086 and 1.216 +/- 0.242%, respectively, p = 0.037). No significant differences were found by the number of CD34+KDR+ cells between the groups. A trend was found to lower number of CD34-KDR+ cells in EA patients compared to control. The differences reached significance on day 1 and 3-5 after endovascular interventions (0.067 +/- 0.022, 0.060 +/- 0.017 and 0.188 +/- 0.052%, respectively, p = 0.024 and p = 0.021). CONCLUSION: The count of blood CD34+ cells in combination with other indicators can be used as an additional factor confirming the presence of chronic myocardial ischemia.