Stress Echocardiography by the ABCDE Protocol ln the Assessment of Prognosis of Stable Coronary Heart Disease.

AIM: To assess the role of clinical indicators and parameters of stress echocardiography performed according to an extended protocol as predictors for the occurrence of a composite cardiovascular endpoint (CCVEP) in IHD. MATERIAL AND METHODS: The study included 186 patients (60.2% men, mean age 60.6±9.9 years) with an established (n=73; 39.2%) and suspected (60.8%) diagnosis of IHD. Stress EchoCG with adenosine triphosphate (38.2%), transesophageal pacing (15.1%), dobutamine (2.6%), and bicycle ergometry on a recumbent ergometer (44.1%) was performed. The stress EchoCG protocol included assessment of regional wall motion abnormalities (WMA), B-lines, LV contractile reserve (CTR), coronary reserve (CR), and heart rate reserve. The median follow-up period was 13 [9; 20] months. The composite CCVEP included death from cardiovascular diseases and their complications, acute coronary syndrome, and revascularization and was defined at the first of these events. Statistical analysis was performed with the Statistica 16.0 and SPSS Statistics 23.0 software packages. Differences were considered statistically significant at p<0.05. RESULTS: Invasive or noninvasive coronary angiography was performed in 90.3% of patients; obstructive coronary disease (stenosis ≥50%) was detected in 67.9% of cases. During the follow-up period, 58 (31.2%) patients had cardiovascular complications. The risk of developing CCVEP was associated with the pretest probability (PTP) of ischemic heart disease (odds ratio, OR, 1.05; 95% confidence interval, CI, 1.02-1.08), dyslipidemia (DLP) (OR 0.40; 95% CI 0.20-0.82), carotid atherosclerosis (OR 0.39; 95% CI 0.18-0.86), LV ejection fraction (OR 0.96; 95% CI 0.93-0.99), appearance at peak stress of new significant (2 LV segments or more) regional WMAs (OR 0.32; 95% CI 0.18-6.55), decreased LV CTR (OR 0.46; 95% CI 0.27-0.79) and CR (OR 0.33; 95% CI 0.18-0.61); p<0.05 for all. In a multivariate analysis with Cox regression, the model with clinical indicators included PTP of IHD (OR 1.04; 95% CI 1.01-1.07; p=0.01) and DLP (OR 0.14; 95% CI 0.02-1.01; p=0.05) as predictors. The model with stress EchoCG parameters included the appearance of new significant WMAs (OR 0.33, 95% CI 0.16-0.65; p=0.001) and reduced <2.0 CR (OR 0.44; 95% CI 0.24-0.82; p=0.01). A comparative analysis of Kaplan-Meier curves confirmed statistically significant differences in the dynamics of the CCVEP occurrence depending on the absence or presence of hemodynamically significant WMAs and/or reduced CR during stress EchoCG (p<0.01). CONCLUSION: Reduced LV CR and WMA during stress EchoCG in patients with suspected or confirmed IHD are significant independent predictors for the CCVEP occurrence. Among clinical indicators, PTP of IHD and DLP are of the greatest importance for prognosis.

Endothelial dysfunction markers and immune response indices in cosmonauts' blood after long-duration space flights.

Space flight factors are known to cause a malfunction in the human immune system and lead to damage to blood vessels. The hemostatic function of endothelium during space missions and its interaction with human immunity has not been determined so far. In this work, we investigated the markers of endothelial activation and damage (plasma concentrations of soluble thrombomodulin fraction (sTM), von Willebrand factor (vWF), highly sensitive C-reactive protein (hs-CRP)), as well as the level of D-dimer and compared them to the immunological parameters characterizing the state of human humoral and cellular immunity. The immune status of long-duration ISS crewmembers was assessed by whole-blood testing, and comprehensive postflight immune assessment included the analysis of leukocyte distribution. Flow cytometry was applied to determine the absolute counts and the percentage of lymphocyte subsets: B cells (CD19+), T cells (CD3+, CD3+CD4+, CD3+CD8+), NK cells (CD3-CD16+CD56+, CD11b+CD56+), and activated subsets (CD3+CD25+ and CD3+HLA-DR+). The in vitro basal cytokine production was investigated in whole blood cell culture. The cytokines IFN-gamma, IL-1-beta, IL-4, IL-6, IL-10, IL-18, and TNF-alpha were measured in plasma and the 24-h supernatants by a sensitive enzyme-linked immunosorbent assay. A significant increase in the plasma levels of vWF and hs-CRP and a decrease in the concentration of sTM after spaceflights were detected. Divergent changes in the parameters characterizing the state of the immune system were observed. We propose that the changes revealed may lead to an increase in the procoagulant activity of blood plasma, suppression of protein C activation and thrombin inhibition, as well as to an increase in the adhesive-aggregate potential of platelets, especially in case of changes in the rheological characteristics of blood flow during re-adaptation to ground conditions. We also speculate that the immune system might play an important role in vessel damage during long-duration missions.

[COMPREHENSIVE ASSESSMENT OF THE HEMOSTASIS SYSTEM IN TEST-SUBJECTS IN EXPERIMENT "MARS-500"].

The paper is devoted to the hemostasis studies in the course of long-term (520 d) isolation in an airtight chamber. Measured parameters included activated partial thromboplastin time (APTT), international normalized ratio (INR), thrombin time (TT); concentrations of fibrinogen (FBG), plasminogen (PG), Willebrand factor (WF), tissue factor pathway inhibitor (TFPI), and tissue plasminogen activator (TPA), thrombomodulin (TM); activities of the coagulation cascade factors (II, V, VII, X, VIII, IX, XI, XII), antithrombin III (ATIII), protein C (PC), C1-inhibitor (C1), α2-antiplasmin (AP), TPA and TFPI. The investigation revealed a diversity of changes in the plasma fibrinogen concentration, slower blood coagulation in the intrinsic pathway and the final stage, and a relative rise in the activities of ATIII and PC-inhibited factors. The rest parameters showed different trends.

[Effect of physical countermeasures against support load deficiency on the hemostasis system in an experiment with 7-day immersion].

In an experiment with 7-d dry immersion for testing the mechanic foot and electrical muscle stimulation procedures of compensating the support load deficiency the following biochemical parameters were studied: activated partial thromboplastin time, prothrombin time, prothrombin index, international normalized ratio, thrombin time (TT), fibrinogen, soluble fibrin-monomer complexes, D-dimer (DD), plasminogen (PG); antithrombin III activity (ATIII), protein C (PC) and alpha2-antiplasmin (AP). Control subjects (immersed w/o stimulation) did not exhibit significant shifts in the hemostasis system: however, they decreased ATIII, PC and PG in the post-experimental period. Mechanic foot stimulation did not have a noteworthy effect on the hemostasis system functioning during immersion, whereas electromyostimulation increased procoagulant and fibrinolytic activity in blood plasma.

[Status of the water-soluble component of the antioxidant defense system in the conditions of 520-day isolation].

In the 520-d chamber experiment within the international project Mars-500 blood samples of 6 male test-subjects of 28 to 39 years of age were analyzed for water-soluble antioxidants: total bilirubin and uric acid; in addition, total antioxidant capacity of blood plasma was determined. Maximal values of these parameters were associated with the most stressful periods of the experiment, i.e. adaptation to the life in isolation and confinement, simulation of the egress onto Martian surface, and change of the diet. On attainment of the homeostatic equilibrium the parameters stabilized on levels slightly lower relative to baseline (pre-isolation) values. Therefore, dynamics of the water-soluble antioxidants reflected adequately the homeostatic reactions to and compensation by organism of the effects of the 520-day life in isolation and confinement.

[Reference values of Russian cosmonauts blood biochemical indices].

Within the period of 2000 to 2012 the values of 40 diagnostically significant biochemical indices in venous blood were being determined during the pre-flight clinical and physiological examination of 28 Russian cosmonauts aged 35 to 54, members of main and back-up crews of expeditions to the International Space Station. The above examination was conducted 45-30 days prior to the launch. Taking account of the fact that each of the most of the cosmonauts performed several flights over the mentioned period and they were repeatedly included in back-up crews over and over again, each of cosmonauts participated in pre-flight examinations 1 to 5 times. Reference values were calculated for each of the studied indices. It was found that reference interval boundaries for 15 indices were narrower as compared to the generally accepted ranges. The upper boundaries of activity reference ranges of a number of enzymes, as well as of concentration of some metabolites of energy and plasticity metabolism were raised relative to mean population values. Thus, it was found that Russian cosmonauts being a specific professional team featured inherent reference values which differed from mean population values in a number of blood biochemical indices. It is conditioned by peculiarities of selection, physical training and psychic and emotional status of crew members during a pre-flight period.

[Intensity of lipid peroxidation and antioxidant protection system indices in the course of a 3-day "dry" immersion experiment].

In the course of a 3-day "dry" immersion experiment involving participation of five male test volunteers aged 25 to 40, in the blood serum of participants were determined the content of LPO (lipid peroxidation) products, namely diene conjugates, malon dialdehyde, shiffbases, as well as the values of the antioxidant protection system (AOP) indices - the concentration of tocopherol as the main lipid antioxidant and the level of general antioxidant activity. During the immersion action no deviations of indices under study from the background values were revealed, with the exception of a certain increase in tocopherol concentration within two hours after experiment beginning. At the restoring period after two hours upon immersion completion a reliable increase of lipid peroxidation products, particularly diene conjugates in participants' blood serum was made evident. At this, the tocopherol content was significantly below the background values. It is therefore concluded that the test participants' adaptation to the simulated weightlessness conditions shows no pronounced stress component, whereas bringing back to normal vital functions after exposure to immersion occurs with significantly pronounced stress reaction development, as demonstrated by considerable growth of LPO processes against the background of AOP system functional activity reducing.

[Metabolic effects of physical countermeasures against deficient weight-bearing in an experiment with 7-day immersion].

Metabolic effects of physical countermeasures against deficient weight-loading were studied in three groups of 21-30 y.o. volunteers for 7-d dry immersion. Blood serum was investigated for 38 biochemical parameters that characterize myocardium, skeletal musculature, hepatobiliary system, kidney, pancreas, GI tract, prostate, and protein-nucleic, carbohydrate, electrolyte and mineral metabolism. Seven-day DI w/o countermeasures (n = 5) increased concentration of conjugated bilirubin, suppressed activities of muscular (creatine phosphokinase MM) and myocardial enzymes (CPK MB, OBDH), and caused an upward trend in cholesterol, its atherogenic LDP fraction and triglycerides. Mechanic sole stimulation (n = 6) intensified, within the physiological norm, erythrocyte hematolysis raising total bilirubin and potassium. Despite the stimulation, activity of muscle and myocardial enzymes made a decrease. Blood creatinine decreased to a less extent than in the immersed group w/o stimulation, however, lipid parameters did not rise. High-frequency stimulation of the lower leg and hip muscles in the course of immersion (n = 5) was noted to heighten the activity of muscle enzymes and potassium level in blood beyond the physiological norm. Change in creatinine did not reach a statistical significance and lipid metabolism parameters were not different from baseline values. Application of these physical methods of counteracting deficiency of weight bearing did not interfere with redistribution of body liquids due to immersion. Values of the parameters under study were mostly within the normal limits throughout the experimental exposure suggesting absence of pathological developments during DI or in consequence of physical stimulation. Therefore, the reactions were obviously of normal adaptive character.

[Intensity of lipid peroxidation and antioxidant protection system indices during re-adaptation period after long-term space flights at the international space station].

In the blood serum of seventeen members of crews which participated in 14 orbital expeditions to the International Space Station with the duration of 125 to 217 days, during the pre-flight period and on the day of landing on the 1st, 7th and 14th days of the rehabilitation period (RP) the content of LPO products was determined, namely diene conjugates (DC), malon dialdehyde (MDA), shiffbases (SB) and the main lipid oxidant - tocopherol (TP). The group of astronauts who made landing in the Space Shuttle spacecraft (8 persons) and the group of astronauts who accomplished space mission in the Soyus TM spacecraft (9 persons) demonstrated a decrease in DC and MDA levels with a rise in TF concentration in the course of the rehabilitation period. Changes in the group of the American spacecraft astronauts were more pronounced. LPO inhibition during the rehabilitation period is recognized [treated] as an adequate reaction to the stress caused by re-adaptation to the ground conditions. Also are discussed probable mechanisms of intergroup differencies in LPO intensity degree: biomembrane phase state changing under the influence of overloads during de-orbiting and stress response intensity during landing in different types of spacecraft.

[Lipid peroxidation and antioxidant protection system in cosmonauts following short-term missions to the International Space Station].

Blood serum of Russian members (n = 21) of the 8 to 12-day visiting missions to the ISS was analyzed before and after mission for products of lipid peroxidation, i.e. diene conjugates, malone dialdehyde, Schiff bases and tocopherol, the primary lipid antioxidant. No reliable change was found in the parameters postflight as compared with preflight values. It may be concluded that 14 days in orbital flight and the factors of re-entry and early recovery do not affect significantly the mechanisms of free radical lipid oxidation and functioning of the antioxidant protection system.

[Dynamics of the protein content of human urine during 5-day immersion].

Variations in the protein spectrum (12 groups) of native daily urine were studied during 5-day dry immersion (DI) of 14 subjects at the age of 19 to 26 years using gradient electrophoresis in polyacrylamide gel. Protein excretion with urine did not alter in the course of the experiment. However, the urine proteins spectrum trended to some shifts. Excretion of low-molecular proteins decreased and of albumin increased pointing to remodulation of tubular reabsorption initiated by the experimental conditions. Steady growth of the Tamm-Horsfall protein concentration seems to be a defense reaction. There was an incremental decrease in immunoglobulins that could be associated with a reduction of glomerular filter permeability for high-molecular proteins.

[Hemostasis system indices after short-term space flights and during 7-day "dry" immersion experiment].

The present paper deals with studying ofhemostasis system indices after short-term (10-11 days) space flights as well as in the course of the experiment with a 7-day "dry" immersion. The following values were determined: activated partial thromboplastin time, prothrombin time, prothrombin index, international normalized ratio (INR), thrombin time (TT); fibrinogen, soluble fibrin-monomer complexes, D-dimer, plasminogen (PG) concentration; activity of antithrombin III (ATIII), protein C (PC), alpha2-antiplasmin (AP). In the 1st day after space flights a fibrinogen concentration was increased significantly as well as TT shortening tendency and fibrinolysis activation tendency were observed. There were no significant changes in ATI I11 and PC activities. During the immersion period there were no significant changes in investigated indices, with the exception of AP activity increase in 3rd day of experiment. In readaptation period, however, a decrease in ATIII and PC activities as well as PG concentration was observed. Hemostasis system response features after space flights and during immersion are probably due to different intensity and duration of external factors effects.

[Evaluation of the 7-day immersion effect on the renal excretory function].

In an experiment with 7-d immersion of 8 male test-subjects (21-26 y.o.) we investigated excretion with urine of total protein, creatinine, urea, uric acid, glucose, K, Na, Ca, P, Mg, 12 groups of proteins and 5 enzymes. Results of the investigation bring to the conclusion that 7-d immersion does not impact the kidney functioning. Analysis of uroproteinogram failed to detect shifts in glomerular filtration or tubular reabsorption which correlates with the absence of significant changes in uroenzymogram. Even profuse diuresis was unable to provoke abnormally high protein and glucose excretion, whereas electrolyte excretion normalized fairly soon. Increased excretion of creatinine, urea, Ca, Mg and P appears to reflect activation of catabolism in skeletal muscles.

[Dynamics of blood biochemical parameters in an experiment with 7-day immersion].

Blood samples were taken from 8 volunteers (21 to 26 years of age) for 7-day immersion 7 days prior to, on days 3 and 7 of the experiment and on days 1 and 8 of recovery. Serum was analyzed for 38 biochemical markers of the functional state of the myocardium, skeletal muscles, hepatobiliary system, kidney, pancreas, GI tract, prostate, and protein-nucleic, carbohydrate, electrolyte and mineral metabolism. Seven-day immersion was found to alter the biochemical parameters within the physiological norm boundaries. The observed changes included lower activities of enzymes associated with muscular and myocardial constellation, shifts in electrolytes (K, Na, Mg), and increases in the biliary function parameters. Increased concentrations of the lipid metabolism parameters suggest a higher risk of atherogenesis. Biochemical parameters of bone tissues and erythrocyte activity were essentially unchanged. Most of the parameters returned to pre-experimental values by day 8 of recovery.

[Effect of 6-month therapy with simvastatin on lipid transport function of the blood and the state of endothelium in patients with diabetes and hypertension].

The state of lipid transport function of the blood, blood contents of stable nitrogen metabolites, and proinflammatory cytokines (TNF-a and IL-1b) during therapy with simvastatin were studied in 29 patients receiving combination antihypertensive therapy with angiotensin converting enzyme inhibitors (ACEI) and verapamil. Lipid lowering action of simvastatin was realized just in 1 month of treatment and remained sustained for half a year (average duration). 6 months after addition of simvastatin to antihypertensive therapy substantial (58.4%, p=0.044) rise of plasma content of stable nitrogen metabolites took place. At the same time therapy with metoprolol in a similar group of patients exerted no considerable effect on blood plasma concentration of nitrate and nitrite anions. Lowering of median values of TNF-alpha from 20.13 (12.67-52.80) to 11.34 (3.31-31.29) pg/ml (p<0.0038) was also noted at the background of combination antihypertensive therapy. This happened without distinct affair with degree of lipid lowering action of simvastatin. The results of the study document positive effect of half year treatment of patients with concomitant hypertension and diabetes with simvastatin (10-20 mg/day) in combination with ACEI and verapamil on metabolism of nitric oxide and plasma content of TNF-alpha which realizes independently from degree of hypolipidemic action of simvastatin.

[Characteristics of cosmonauts' metabolism after extended missions on the international space station].

In eight Russian members of the ISS crews 1 to 5 enzymes and some other metabolites were analyzed in blood in the pre- launch period, on the landing day, and on days 6-8 and 14-19 of recovery. Deviations in the biochemical parameters were typically within the physiological norm without clinical implications. Biochemical deviations on the landing day seemed to relate to metabolic shifts due to long-term microgravity and, on the other hand, were a reaction to acute gravitational stress on return to 1 g. Dynamics of a number of parameters was markedly different as compared with the data from cosmonauts who had made long missions to the Mir space station, but this can be attributed to different g-profiles during descent and blood sampling schedule. In two to three wks the parameters regained normal values suggesting that negative effects of readaptation to the Earth's gravity were fully remedied.

[Lipid peroxidation and activity of diagnostically important blood enzymes in rats during 35 days head-down suspension]. / Perekisnoe okislenie lipidov i aktivnost' diagnosticheski znachimykh fermentov krovi u krys pri 35-sutochnom vyveshivanii v antiortostaticheskom polozhenii.

In the experiment with 35-d head-down suspension of rats concentrations of lipid peroxidation (LPO) products and values of antioxidant defense (AOD) parameters were determined in the lever, skeletal muscles, myocardium, and blood plasma. In addition, activity of 11 plasma enzymes characteristics of these tissues was evaluated. LPO was found to be activated in the lever, myocardium and skeletal muscles in the first and 4-5 weeks of suspension. The period between weeks 2 and 4 marked phase variation of LPO intensity which could have baseline or increased values. Plasma LPO was inhibited due to AOD activation pointing to compensatory processes on the level of organism and absence of pathologies in the organs and tissues under study. As a rule, activity of the plasma enzymes directly or indirectly participating in energy metabolism was reduced. Enzymes-catalysts of other types of metabolism predominantly elevated activity during LPO intensification. Canonic analysis established a significant correlation of LPO, AOD and activity of plasma enzymes, and LPO and AOD in the rat's lever and plasma enzymes. These correlations between LPO, AOD and activity of diagnostically important enzymes can be used to diagnose and predict changes in the state of organism caused by simulated factors of space flight.

[Lipid peroxidation and activity of diagnostically significant enzymes in cosmonauts after flights of various durations]. / Perekisnoe okislenie lipidov i aktivnost' diagnosticheski znachimykh fermentov u kosmonavtov posle poletov razlichnoi prodolzhitel'nosti.

Concentrations of the products of peroxide oxidation of lipids (POL), indices of the system of antioxidant defence (SAD), and the activity of 13 diagnostically significant organic/tissue specific enzymes (DSE) were determined in blood serum of cosmonauts who had participated in short (5-9 days, n = 8), long (125-179 days, N = 15), and superlong (241-366 days, n = 5) missions. To feature an interrelation of the indices under study, the canonical correlation analysis of a set of POL and SAP parameters and DSE activity was performed. Compared with pre-flight values, changes in the POL and SAP parameters were significant in serum only after the long-duration missions. Signs of POL activation were noted following the superlong missions. After the long-duration missions increased was the activity (mainly, within the norm) of DSEs, specific for the organs and tissues functioning of which is stressed in the period of post-flight readaptation (skeletal muscles, myocardium, liver). After the superlong missions, the DSE activity either remained essentially unchanged or decreased. In all the tested groups, highly reliable correlations between POL, SAP, and the DSE activity, traditionally applied in clinical diagnostics, were observed. These advocate for the use of POL and SAP indices in medical diagnostics and prognosis of cosmonauts' health.