The use of computer simulation methods has become an indispensable component in identifying drugs against the SARS-CoV-2 coronavirus. There is a huge body of literature on application of molecular modelling to predict inhibitors against target proteins of SARS-CoV-2. To keep our review clear and readable, we limited ourselves primarily to works that use computational methods to find inhibitors and test the predicted compounds experimentally either in target protein assays or in cell culture with live SARS-CoV-2. Some works containing results of experimental discovery of corresponding inhibitors without using computer modelling are included as examples of a success. Also, some computational works without experimental confirmations are also included if they attract our attention either by simulation methods or by databases used. This review collects studies that use various molecular modelling methods: docking, molecular dynamics, quantum mechanics, machine learning, and others. Most of these studies are based on docking, and other methods are used mainly for post-processing to select the best compounds among those found through docking. Simulation methods are presented concisely, information is also provided on databases of organic compounds that can be useful for virtual screening, and the review itself is structured in accordance with coronavirus target proteins.

Two solvent models, COSMO (old parametrization) and COSMO2 (new parametrization) are compared for a set of protein–ligand complexes in quantum quasi-docking, which is two-stage docking: positioning of a ligand in a target protein and calculation of binding enthalpy of the protein–ligand system using the PM7 quantum-chemical semiempirical method. In quantum quasi-docking, a wide spectrum of unique low-energy minima of the protein–ligand system is first found while employing the classical force field. Then energies of all these minima are recalculated within one of the continual models using the modern PM7 method with allowance for the solvent, and the global energy minimum is determined among the recalculated energies. The solution of the quantum quasi-docking problem is the position of the ligand in the protein corresponding to the global minimum of the protein–ligand system energy calculated by the quantum-chemical method with allowance for the solvent. Effectiveness of quantum quasi-docking is defined by the value (below 2 Å) of the root-mean-square deviation of ligand atoms from one another in two positions, namely, the position of the ligand in the protein corresponding to the calculated global energy minimum and the experimentally found crystallized position of the ligand with the protein. Comparison is performed for ten protein–ligand test complexes with well-defined structures taken from the Protein Data Bank, for which the ligand–protein binding enthalpy is measured and the positioning of the ligand in the protein is successful in quasi-docking within both solvent models used. In both methods, PM7 + COSMO and PM7 + COSMO2, a high correlation coefficient of the experimental and calculated ligand–protein binding enthalpy is obtained for both calculation techniques. Allowance for moveability of protein atoms in calculations of binding enthalpy leads to an increase in its negative values and to a slight decrease in the correlation coefficient of the experimental and calculated values. The role of hydrogen bonds between protein and ligand atoms is revealed: their contribution to binding enthalpy ranges from 14 to 24

Computer aided structural based approach was used to find inhibitors of SARS-CoV-2 nsp16 (2'-O-methyltransferase). Docking based virtual screening of three libraries, Enamine Coronavirus Library, Enamine Nucleoside Mimetics Library, and Chemdiv Nucleoside Analogue Library, was performed. In total, 39350 3D-structures of low molecular weight ligands were docked into a model of nsp16 prepared using the structure of 6WKQ complex from the Protein Data Bank. Docking was performed by the SOL docking program. For the best SOL scored ligands, the protein-ligand binding enthalpy was calculated using the PM7 semiempirical quantum-chemical method with the COSMO implicit solvent model. The most promising eleven compounds were purchased and their inhibitory activity against the recombinant viral nsp16 protein was measured using MST assay with Monolith NT.115. As a result, two compounds, Z195979162 and Z1333277068, from Enamine Coronavirus Library demonstrated dissociation constants Kd for nsp16/nsp10 complex equal to 2.0 and 5.0 μM. The relative stability of these ligands in their docked positions in the nsp16 S-adenosylmethionine (SAM) binding site was confirmed in the molecular dynamics simulations along 70 ns trajectories. Z195979162 and Z1333277068 compounds belong to two chemical classes: 1,4-disubstituted tetrahydropyridines and derivatives of pyrazole-5-carboxamide, respectively, and can be good starting points for further hit optimization in the field of nsp16 inhibitors design.

A virtual structure-oriented screening of candidates for inhibitors of blood coagulation factor XIIa was carried out. This coagulation factor is one of the most promising therapeutic targets for the development of anticoagulants without disturbing normal hemostasis. The screening was carried out in the database of organic compounds of the Voronezh State University, consisting of more than 19 thousand molecules. At the first stage of virtual screening, ligands were positioned in the active center of factor XIIa using the SOL docking program. At the second stage, for the best ligands, the protein-ligand binding enthalpy was calculated using the MOPAC program and the PM7 quantum-chemical method, taking into account the solvent in the COSMO continuum model. All calculations were carried out using the supercomputing resources at Lomonosov Moscow State University. In total, more than 30 thousand ligand conformers are docked, and for more than 400 of the best of them, the protein-ligand binding enthalpy was calculated. 16 compounds are selected as the most promising candidates for subsequent in vitro testing of their ability to inhibit factor XIIa.

Docking and quantum-chemical methods have been used for screening of drug-like compounds from the own database of the Voronezh State University to find inhibitors the SARS-CoV-2 main protease, an important enzyme of the coronavirus responsible for the COVID-19 pandemic. Using the SOL program more than 42000 3D molecular structures were docked into the active site of the main protease, and more than 1000 ligands with most negative values of the SOL score were selected for further processing. For all these top ligands, the protein-ligand binding enthalpy has been calculated using the PM7 semiempirical quantum-chemical method with the COSMO implicit solvent model. 20 ligands with the most negative SOL scores and the most negative binding enthalpies have been selected for further experimental testing. The latter has been made by measurements of the inhibitory activity against the main protease and suppression of SARS-CoV-2 replication in a cell culture. The inhibitory activity \of the compounds was determined using a synthetic fluorescently labeled peptide substrate including the proteolysis site of the main protease. The antiviral activity was tested against SARS-CoV-2 virus in the Vero cell culture. Eight compounds showed inhibitory activity against the main protease of SARS-CoV-2 in the submicromolar and micromolar ranges of the IC50 values. Three compounds suppressed coronavirus replication in the cell culture at the micromolar range of EC50 values and had low cytotoxicity. The found chemically diverse inhibitors can be used for optimization in order to obtain a leader compound, the basis of new direct-acting antiviral drugs against the SARS-CoV-2 coronavirus.

Docking and quantum-chemical methods have been used for screening of drug-like compounds from the own database of the Voronezh State University to find inhibitors the SARS-CoV-2 main protease, an important enzyme of the coronavirus responsible for the COVID-19 pandemic. Using the SOL program more than 42000 3D molecular structures were docked into the active site of the main protease, and more than 1000 ligands with most negative values of the SOL score were selected for further processing. For all these top ligands, the protein-ligand binding enthalpy has been calculated using the PM7 semiempirical quantum-chemical method with the COSMO implicit solvent model. 20 ligands with the most negative SOL scores and the most negative binding enthalpies have been selected for further experimental testing. The latter has been made by measurements of the inhibitory activity against the main protease and suppression of SARS-CoV-2 replication in a cell culture. The inhibitory activity \of the compounds was determined using a synthetic fluorescently labeled peptide substrate including the proteolysis site of the main protease. The antiviral activity was tested against SARS-CoV-2 virus in the Vero cell culture. Eight compounds showed inhibitory activity against the main protease of SARS-CoV-2 in the submicromolar and micromolar ranges of the IC50 values. Three compounds suppressed coronavirus replication in the cell culture at the micromolar range of EC50 values and had low cytotoxicity. The found chemically diverse inhibitors can be used for optimization in order to obtain a leader compound, the basis of new direct-acting antiviral drugs against the SARS-CoV-2 coronavirus.

The paper presents the results concerning the application of docking programs FLM to combined use of the MMFF94 force field and the semiempirical quantum-chemical method PM7 in the docking procedure. At the first step of this procedure a fairly wide range of low-energy minima of the protein-ligand complex is found in the frame of the MMFF94 force field using the FLM program. The energies of all these minima are recalculated using the PM7 method and the COSMO solvent continuum model at the second step. On the basis of these calculations the deepest minimum of the protein-ligand energy, calculated by the PM7 method with COSMO solvent, is determined, which gives the position of the ligand closest to its position in the crystal of the protein-ligand complex. It is shown that the first step of the combined procedure is performed more quickly and more efficiently in vacuum, rather than with a solvent model.

The paper presents the results concerning the use of the supercomputer docking program SOL-P, which performs a search for low-energy minima of protein—ligand complexes in the MMFF94 force field without using a grid of precalculated potentials for protein—ligand interactions. The SOL-P docking program can be applied to the generalized docking of ligands with a large number of internal rotational degrees of freedom (torsions). This program is based on a tensor train global optimization algorithm. The SOL-P program was successfully applied to the docking of oligopeptide ligands consisting of 3–6 amino acid residues and having 18–25 internal rotational degrees of freedom.

The blood coagulation system plays an important role in health and disease. It is a complex network of proteolytic reactions that is activated during injuries and controls the formation of a fibrin clot. Although new components and reactions have not been discovered for thirty years, during this time there has been a revolution in understanding of how this system works and what enzymes are the optimal targets for the therapy. At the same time, new methods of drug development, first of all, computer docking, which are ideally suited for the discovery of inhibitors of blood clotting enzymes, have appeared. In this review, an attempt has been made to correlate the lines of development of new ideas about the mechanisms of coagulation, new methods of searching for drugs and their combination, thanks to which now there are more and more potentially interesting molecules that can change the face of the anticoagulant therapy in the near future. In the review, molecular modeling methods, primarily docking, which are increasingly used at the initial stage of developing new drugs, the role of docking at the initial stage of developing new inhibitors are briefly considered and the structure of the active centers of factors Xa and XIa, which determines their interaction with inhibitors, are discussed in detail.

Aim. To evaluate the 5-year results of renal denervation (RDN) in patients with resistant arterial hypertension (AH). Materials and methods. The study included 14 patients to whom, during the 2011-2013 period RDN has been completed. Before and after the intervention, office blood pressure, quality of life indicators according to the EQ-5D questionnaire, mass index bodies, indicators of kidney function were duly assessed. Results. Five years after RDN, office BP decreased from 165/110 to 139/95 mm Hg. Art. (p

AIM:to investigate the myocardial expression of some structural proteins and markers of cellular proliferation and innate immunity for assessing their possible diagnostic and prognostic role in patients with chronic myocarditis.SUBJECTS AND METHODS:The investigation enrolled 23 patients (16 men; mean age, 52.0±12.4 years (range, 27 to 73) with various forms of noncoronarogenic myocardial injury who underwent right ventricular endomyocardial biopsy (n=4), intraoperative left ventricular biopsy (n=17) or autopsy (n=2). Prior to their morphological examination, the patients were divided into two groups: 1) 10 patients with dilated cardiomyopathy and presumptive myocarditis; 2) 13 patients with valvular heart disease, hypertrophic cardiomyopathy, myxoma, and chronic pulmonary thromboembolism, presumptively without myocarditis. Along with myocardial histological and immunohistochemical (IHC) examinations, the expression of vimentin, desmin, c-kit, Ki-67, and Toll-like receptors (TLR) 2 and 9 was determined. Polymerase chain reaction was used to identify whether herpes viruses of and parvovirus B19 genomes were present in the blood and myocardial samples; indirect ELISA was applied to estimate the blood level of antibodies against various cardiac antigens.RESULTS:According to the histological findings, active/borderline lymphocytic myocarditis was diagnosed in all the patients (Group 1) and in 6 patients (Group 2) in conjunction with the underlying disease (only in 9 and 7 patients, respectively), viral genome was detected in the myocardium of 15 patients, including in 5 without morphological signs of myocarditis (parvovirus B19 (n=11), herpesvirus 6 (n=4), herpes simplex virus types 1 and 2 (n=1), Epstein-Barr virus (n=2), and cytomegalovirus (n=1)), and in the blood (n=4). A marked correlation was found between TLR2 and TLR9 expressions and the morphological pattern of active myocarditis in the absence of this correlation with the expression level of other studied markers. The expression level of TLR2 in patients with and without borderline myocarditis was 0 [0; 0,75] and in those with active myocarditis was 1.5 [1; 1,5] points; that of TLR9 was 2 [2; 2] and 4 [3; 4] points, respectively (p<0.001). The expression of TLR2 and TLR9 in patients with borderline myocarditis was lower than in those without myocarditis (0 [0; 0] versus 0 [0; 1] and 2 [1,5; 2] versus 2 [2; 3] points), which can reflect cardiomyocyte destruction/depletion at later stages of the disease. There was also a close correlation between the expression level of TLR2 and that of TLR9 (r=0.824; p<0.001) and with Ki-67 levels (r=-0.531 and r=-0.702; p<0.01). There was also a correlation of the expression of the studied markers with viral persistence (desmin), the degree of myocardial dysfunction and cardiosclerosis (c-kit), which calls for further investigations.CONCLUSION:Determination of the myocardial expression level of TLR2 and TLR9 may serve as an immunohistochemical marker for myocarditis and preservation of its activity, which is especially valuable in patients with borderline forms. The marked expression of these markers for innate immunity may reflect both one of the mechanisms of genetic predisposition to myocarditis and its severe course and their secondary activation in the pathogenesis of the disease and is a potential target of therapy.

Results of the combined use of the classical force field and the recent quantum chemical PM7 method for docking are presented. Initially the gridless docking of a flexible low molecular weight ligand into the rigid target protein is performed with the energy function calculated in the MMFF94 force field with implicit water solvent in the PCM model. Among several hundred thousand local minima, which are found in the docking procedure, about eight thousand lowest energy minima are chosen and then energies of these minima are recalculated with the recent quantum chemical semiempirical PM7 method. This procedure is applied to 16 test complexes with different proteins and ligands. For almost all test complexes such energy recalculation results in the global energy minimum configuration corresponding to the ligand pose near the native ligand position in the crystalized protein-ligand complex. A significant improvement of the ligand positioning accuracy comparing with MMFF94 energy calculations is demonstrated.

The novel docking algorithm is presented and it is applied to the docking problem with flexible ligand and moveable protein atoms. The energy of the protein-ligand complex is calculated in the frame of the MMFF94 force field in vacuum. The conformation space of the system coordinates is formed by translations and rotations of the ligand as a whole, by the ligand torsions and also by Cartesian coordinates of the selected target protein atoms. The algorithm is realized in the novel parallel docking SOL-P program and results of its performance for a set of 30 protein-ligand complexes are presented. It is shown that mobility of the protein atoms improves docking positioning accuracy. The SOL-P program is able to perform docking of a flexible ligand into the active site of the target protein with several dozen of protein moveable atoms – up to 157 degrees of freedom.

Preparation of the target-protein, particularly the protein protonation method can affect considerably the spatial arrangement of the attached hydrogen atoms and the charge state of individual molecular groups in amino acid residues. This means that the calculated protein-ligand binding energies can vary significantly depending on the method of the protein preparation, and it also can lead to the different docked positions of the ligand in the case of docking (positioning of the ligand in the protein active site). This work investigates the effect of the hydrogen atoms arrangement method in the target protein on the protein-ligand binding energy. All hydrogen atoms of target-protein are fixed or movable. The comparison of the protein-ligand binding energies obtained for the test set of target-proteins prepared using six different programs is performed and it is shown that the protein-ligand binding energy depends significantly on the method of hydrogen atoms incorporation, and differences can reach 100 kcal/mol. It is also shown that taking into account solvent in the frame of one of the two continuum implicit models smooths out these differences, but they are still about 10 - 20 kcal/mol. Moreover, we carried out the docking of the crystallized (native) ligands from the protein-ligand complexes using the SOL program and showed that the different methods of the hydrogen atoms addition to the protein can give significantly different results both for the positioning of the native ligand and for its protein-ligand binding energy.

AIM:To determine the diagnostic value of different clinical, laboratory, and instrumental signs in the diagnosis of myocarditis in patients with the picture of idiopathic arrhythmias, dilated cardiomyopathy (DCM) and in a comparison group when comparing with myocardial morphological examination. SUBJECTS AND METHODS:A study group included 100 patients (35 women; mean age, 44.7±12.5 years) with idiopathic arrhythmias (n=20) and DCM as a syndrome (n=100). All underwent myocardial morphological examination: endomyocardial biopsy (EMB) (n=71), intraoperative biopsy (n=13), study of the explanted heart (n=6), and autopsy (n=11). A comparison group consisted of 50 patients (25 women; mean age, 53.7±11.7 years) with non-inflammatory diseases of the heart (left ventricular end-diastolic dimension <6.0 cm, ejection fraction >50%) who underwent open-heart surgery (n=47), EMB (n=2), or autopsy (n=1). The investigators also performed polymerase chain reaction for cardiotropic viral DNA in the blood and myocardium, anticardiac antibody (ACA) identification, myocardial scintigraphy (n=26), coronary angiography (n=47), magnetic resonance imaging (MRI) (n=25), and multislice computed tomography of the heart (n=45). The diagnostic value of the extended spectrum of clinical, laboratory, and instrumental markers for myocarditis was estimated. RESULTS:Active/borderline myocarditis was diagnosed in 76% of the patients in the study group (75.5% in the arrhythmia subgroup and 76.3% in the DCM one) and in 24.3% of those in the comparison group (p<0.001). A viral genome in the myocardium was detected statistically significantly less frequently in the study group than that in the comparison one (40.2 and 65%, respectively; p<0.01): in 46.6% in the DCM subgroup and 15.8% in the arrhythmia one. An ACA set (sensitivity, specificity, and predictive value of positive and negative test results (45.7, 80, 80.4, and 45%, respectively)) was of the greatest diagnostic importance in identifying myocarditis; antibodies to cardiomyocyte nuclei in a titer of 1:160-1:320 had the highest specificity (93.3%). A specificity above 70% was seen for a full medical history triad (acute onset, an association between onset and infection, a symptom duration of less than one year), systemic immune manifestations, anginas in the history and elevated anti-O-streptolysin levels, systemic blood changes, Q waves/QS complexes on ECGs, local hypokinesias, pericardial effusion, atriomegalia (in arrhythmias), angina/ischemia with intact coronary arteries, and focal perfusion defects during myocardial scintigraphy. A sensitivity higher than 50% was observed for age over 40 years (differential diagnosis with genetic forms), acute onset, a correlation with infection, and delayed contrast agent accumulation, as evidenced by MSCT/MRI. CONCLUSION:When the incidence of myocarditis is similar in the arrhythmia and DCM subgroups, the viral genome detection rate is statistically significantly higher in DCM. Among the non-invasive markers, an ACA set (high sensitivity and specificity) is of the greatest diagnostic value in the diagnosis of myocarditis. The diagnostic rule based on counting the number of scores has been developed, which makes it possible to individually establish the risk of myocarditis in patients with idiopathic arrhythmias and DCM for both the determination of indications for biopsy and the lack of the possibility of its performance. The risk of myocarditis is high if there are 5-7 scores; that is close to 100% if there are 8 scores or more.

The primary diagnosis of “dilation cardiomyopathy” is syndromal, and demands clarification of nosological origins. In the article, the specifics of such diagnostics is discussed. Clinical case is provided that illustrates the ways of management, diagnostics and treatment of the essential (primary, genetically determined) dilation cardiomyopathy. Patient of 22 year old with no family history, at the ages 20 and 21 y.o. had cardioembolic strokes. Paroxysmal atrial fibrillation was found, raised creatine kinase levels up to 349-1045 U/L, decreased ejection fraction 17%. Heart failure rapidly progressed. In endomyocardial biopsy there was homogenisation of cardiomyocytes, subendocardial lipomatosis with borderline virus-negative myocarditis. By Senger direct sequencing, the novel variant p.E372 in gene LMNA was found, heterozygous. Implantation of CRT-D was done, and in 4 months — cardiac transplant.

Dilation cardiomyopathy (DCMP) remains a disease with poor prognosis.Aim. To study the importance of risk stratification improvement for fatal outcomes, especially sudden cardiac death (SCC), with the aim for on-time prevention procedures, as the previously proposed non-invasive electrophysiological predictors — heart rhythm turbulence (HRT) and variability (HRV), microvolt alternation of T wave (mTWA), deceleration capacity (DC) and acceleration capacity (AC) in DCMP are not studied well enough.Material and methods. During 4 years there was follow-up of 54 DCMP patients and sinus rhythm at the age 42 [30;58] year-old (36 males) and control group — 54 persons with no cardiovascular pathology (32 males, mean age 47 [27;64] y.o.). At baseline the Holter monitoring was done, of ECG with HRV, HRT, DC, AC, mTWA assessment, and echocardiography. Patients took standard treatment of chronic heart failure (CHF); part of cardioverter-defibrillator (CD) implanted was 18,5%.Results. Mean ejection fraction (EF) in the main group was 32% [22;38], signs of CHF had 93% of patients. Those with DCMP differed from the main group by significantly lower values of SDNN, pNN50, DC, TO, TS, higher AC and mTWA in early morning. During 4 years there was 1 SCD, and 7 died from CHF progression; there was 1 adequate shock in CD patient (totally 9 deaths). Comparing to those survived, died patients had had lower EF, HRV, DC, maximal mTWA values, higher end diastolic volume, CHF class, AC, mTWA, number of episodes of non-sustained ventricular tachycardia (nsVT) in morning. Under monofactorial analysis there was significant influence on fatal outcome risk of the following (in order of declining significance): EF (odds ratio (OR) 32), SDNN (OR 21), DC (OR 9), AC (OR) 7, pNN50 (OR 6), nsVT (OR 5,2; p=0,05). In multifactor analysis the only independent predictor of fatal outcomes was the decrease of EF of the left ventricle less than 26% (sensitivity 80%, specificity 90%).Conclusion. DCMP patients, comparing to persons with no cardiovascular pathology, have decreased HRV and DC, increased AC, more common pathological HRT, increase of mTWA in early morning, and in those died these specifics was more prominent. In monofactor analysis the non-invasive electrophysiological predictors associated with poor DCMP prognosis, were AC, SDNN DC, pNN50, nsVT. However the most significant and the only independent predictor of fatal outcomes in DCMP patients is the decrease of EF. If to apply the EF less than 26% as a criteria of high risk, it predicts the 32 times increase of fatal outcomes risk with sensitivity 80% and specificity 90%.

AIM:To evaluate the efficiency of immunosuppressive therapy (IST) in virus-negative (V-) and virus-positive (V+) patients with lymphocytic myocarditis (LM). SUBJECTS AND METHODS:60 patients (45 males) (mean age 46.7±11.8 years) with dilated cardiomyopathy (mean left ventricular (LV) end diastolic size (EDS) 6.7±0.7 cm; ejection fraction (EF) 26.2±9.1%) were examined. The diagnosis of active/borderline LM was verified by right ventricular endomyocardial biopsy in 38 patients, by intraoperative LV biopsy in 10, in the study of explanted hearts from 3 patients and at autopsy in 9. The investigators determined the genomes of parvovirus B19, herpes viruses types 1, 2 and 6, Epstein-Barr (EBV), zoster, and cytomegalovirus in the blood and myocardium and, if antibodies were present in the blood, hepatitis B and C viruses, as well as antibodies against antigens in the endothelium, cardiomyocytes and their nuclei, smooth muscles, fibers of the conducting system. IST was used in terms of histological, immune, and viral activities. IST was performed in 22 V+ patients (Group 1) and in 24 V- patients (Group 2); this was not done in 10 V+ patients (Group 3) and V- patients (Group 4). IST comprised methylprednisolone at a mean dose of 24 mg/day (n=40), hydroxychloroquine 200 mg/day (n=20), azathioprine at a mean dose of 150 mg/day (n=21); antiviral therapy included acyclovir, ganciclovir, intravenous immunoglobulin (n=24). The follow-up period was 19 (7.3-40.3) months. RESULTS:The viral genome was detected in the myocardium of 32 patients who made up a V+ group. The degree of histological activity did not differ in relation to the presence of viral genome in the myocardium. The degree of immune activity (anticardiolipin antibody titers) in the V+ patients was as high as that in V- ones. At baseline, the V+ patients had a significantly higher LV EDS and a lower EF than the V- patients. Overall, IST only could lead to a significant increase in EF (from 26.5±0.9 to 36.0±10.8%; p<0.001) and reductions in NYHA functional class from III to II (p<0.001), LV EDS (from 6.7±0.7 to 6.4±0.8 cm; p<0.01), pulmonary artery systolic pressure (from 48.9±15.5 to 39.4±11.5 mm Hg (p<0.01); the IST group had significantly lower mortality rates than the non-IST group (23.9 and 64.3%; p<0.01). At the same time, a significant trend was seen in both V- and V+ patients. The mortality rate in the V+ patients, as a whole, was higher (46.9 and 17.9%; p<0.05). CONCLUSION:IST leads to a significant improvement of functional indices and it is associated with lower mortality rates in both myocardial V- and V+ patients with LM. A more than 10% EF increase in the first 2 months is associated with a good prognosis. The presence of viral genome in the myocardium (primarily herpesviruses rather than parvovirus-19) is accompanied by more severe initial dysfunction, a less pronounced effect of IST, and higher mortality rates. However, the positive effect of IST also persists in V+ patients. No positive changes (a decrease in EF was observed) were absent only in IST-naïve V+ patients.