[Miocarditis in Patients with COVID-19 Confirmed by Immunohistochemical]

Combined Heart Injuries on the Data of Contrast-Enhanced Cardiac Magnetic Resonance Imaging in Patients With Post-Covid Syndrome

Aim      Prospective assessment of the nature of cardiac injury in patients with post-COVID syndrome according to contrast-enhanced MRI in routine clinical practice.Material and methods  106 previously unvaccinated patients were evaluated. 62 (58.5%) of them were women with complaints that persisted after COVID-19 (median age, 57.5 [49; 64] years). In addition to standard indexes, markers of inflammation and myocardial injury were determined, and cardiac contrast-enhanced MRI was performed in each patient.Results The median time from the onset of COVID-19 to cardiac MRI was 112.5 [75; 151] days. The nature of cardiac injury according to MRI in patients with post-COVID syndrome was complex and included a decrease in left ventricular (LV) and right ventricular ejection fraction, pericardial effusion, and pathological foci of late and early contrast enhancement at various locations. In 29 (27.4%) cases, there was a combination of any two signs of heart injury. In 28 (26.4%) patients with focal myocardial injury during the acute phase of COVID-19, hydroxychloroquine and tocilizumab were administered significantly more frequently, but antiviral drugs were administered less frequently. The presence of focal myocardial injury was associated with pathological LV remodeling.Conclusion      According to contrast-enhanced cardiac MRI, at least 27.4% of patients with post-COVID syndrome may have signs of cardiac injury in various combinations, and in 26.4% of cases, foci of myocardial injury accompanied by LV remodeling are detected. The nature of heart injury after COVID-19 depends on the premorbid background, characteristics of the course of the infectious process, and the type of prescribed therapy. An algorithm for evaluating patients with post-COVID syndrome is proposed.

Toll-like receptor (TLRs) agonists and antagonists for COVID-19 treatments

Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) rapidly infects humans and animals which make coronavirus disease 2019 (COVID-19) a grievous epidemic worldwide which broke out in 2020. According to data analysis of the other coronavirus family, for instance severe acute respiratory syndrome SARS coronavirus (SARS-CoV), can provide experience for the mutation of SARS-CoV-2 and the prevention and treatment of COVID-19. Toll-like receptors (TLRs) as a pattern recognition receptor (PRRs), have an indispensable function in identifying the invader even activate the innate immune system. It is possible for organism to activate different TLR pathways which leads to secretion of proinflammatory cytokines such as Interleukin 1 (IL-1), Interleukin 6 (IL-6), Tumor necrosis factor α (TNFα) and type Ⅰ interferon. As a component of non-specific immunity, TLRs pathway may participate in the SARS-CoV-2 pathogenic processes, due to previous works have proved that TLRs are involved in the invasion and infection of SARS-CoV and MERS to varying degrees. Different TLR, such as TLR2, TLR4, TLR7, TLR8 and TLR9 probably have a double-sided in COVID-19 infection. Therefore, it is of great significance for a correctly acknowledging how TLR take part in the SARS-CoV-2 pathogenic processes, which will be the development of treatment and prevention strategies.

Chronic biopsy proven post-COVID myoendocarditis with SARS-Cov-2 persistence and high level of antiheart antibodies

PURPOSE

To study the clinical signs and mechanisms (viral and autoimmune) of myoendocarditis in the long-term period after COronaVIrus Disease 2019 (COVID-19).

METHODS

Fourteen patients (nine male, 50.1 ± 10.2 y.o.) with biopsy proven post-COVID myocarditis were observed. The diagnosis of COVID-19 was confirmed by IgG seroconversion. The average time of admission after COVID-19 was 5.5 [2; 10] months. An endomyocardial biopsy (EMB) of the right ventricle was obtained. The biopsy analysis included polymerase chain reaction diagnosis of viral infection, morphological, immunohistochemical (IHC) examination with antibodies to CD3, CD45, CD68, CD20, SARS-Cov-2 spike, and nucleocapsid antigens. Coronary atherosclerosis was ruled out in all patients over 40 years.

RESULTS

The new cardiac symptoms (congestive heart failure 3-4 New York Heart Association class with severe right ventricular involvement, various rhythm, and conduction disturbances) appeared 1-5 months following COVID-19. Magnetic resonance imaging showed disseminated or focal subepicardial and intramyocardial late gadolinium enhancement, hyperemia, edema, and increased myocardial native T1 relaxation time. Antiheart antibodies levels were increased 3-4 times in 92.9% of patients. The mean left ventricular (LV) ejection fraction (EF) was 28% (24.5; 37.8). Active lymphocytic myocarditis was diagnosed in 12 patients, eosinophilic myocarditis in two patients. SARS-Cov-2 RNA was detected in 12 cases (85.7%), in association with parvovirus B19 DNA-in one. Three patients had also endocarditis (infective and nonbacterial, with parietal thrombosis). As a result of steroid and chronic heart failure therapy, the EF increased to 47% (37.5; 52.5).

CONCLUSIONS

COVID-19 can lead to long-term severe post-COVID myoendocarditis, that is characterized by prolonged persistence of coronavirus in cardiomyocytes, endothelium, and macrophages (up to 18 months) in combination with high immune activity. Corticosteroids and anticoagulants should be considered as a treatment option of post-COVID myoendocarditis.

MATHEMATICAL MODEL FOR THE INVESTIGATION OF HYPOXIC STATES IN THE HEART MUSCLE AT VIRAL DAMAGE

The main complications of organism damaged by SARS-CoV-2 virus are various cardiovascular system lesions. As a result, the secondary tissue hypoxia is developed and it is relevant to search the means for hypoxic state alleviation. Mathematical modeling of this process, followed by the imitation of hypoxic states development, and subsequent correction of hypoxia at this model may be one of the directions for investigations. Aim. The purpose of this study was to construct mathematical models of functional respiratory and blood circulatory systems to simulate the partial occlusion of blood vessels during viral infection lesions and pharmacological correction of resulting hypoxic state. Methods. Methods of mathematical modeling and dynamic programming were used. Transport and mass exchange of respiratory gases in organism, partial occlusion of blood vessels and influence of antihypoxant were described by the systems of ordinary nonlinear differential equations. Results. Mathematical model of functional respiratory system was developed to simulate pharmacological correction of hypoxic states caused by the complications in courses of viral infection lesions. The model was based on the theory of functional systems by P. K. Anokhin and the assumption about the main function of respiratory system. The interactions and interrelations of individual functional systems in organism were assumed. Constituent parts of our model were the models of transport and mass exchange of respiratory gases in organism, selforganization of respiratory and blood circulatory systems, partial occlusion of blood vessels and the transport of pharmacological substance. Conclusions. The series of computational experiments for averaged person organism demonstrated the possibility of tissue hypoxia compensation using pharmacological substance with vasodilating effect, and in the case of individual data array, it may be useful for the development of strategy and tactics for individual patient medical treatment.

[Clinical and morphological characteristics of SARS-CoV-2-related myocarditis proven by the presence of viral RNA and proteins in myocardial tissue]

OBJECTIVE

To investigate the clinical and morphological features of SARS-CoV-2-related myocarditis, by determining the presence of viral RNA and proteins in myocardial tissue.

MATERIAL AND METHODS

The study was conducted to examine the material of 32 autopsies with a confirmed diagnosis of myocarditis. There were data of a morphological study, including a standard histological study, as well as immunohistochemical determination of the surface markers CD45, CD3, CD20, and CD68 cells of an inflammatory infiltrate and virus proteins (SARS-CoV-2 nucleocapsid protein and spike protein). Positive and negative control tests were carried out. In addition, coronavirus RNA was detected in the myocardium using a polymerase chain reaction.

RESULTS

Polymerase chain reaction (PCR) revealed viral RNA in myocardial tissue. Viral proteins were identified in the macrophages of an inflammatory infiltrate and cardiomyocytes.

CONCLUSION

The findings may suggest that the virus persists in the myocardium and chronic myocarditis develops.

Subacute and chronic post-covid myoendocarditis: clinical presentation, role of coronavirus persistence and autoimmune mechanisms

Aim    To study clinical features of myoendocarditis and its possible mechanisms, including persistence of SARS-Cov-2 in the myocardium, in the long-term period following COVID-19.Material and methods    This cohort, prospective study included 15 patients aged 47.8±13.4 years (8 men) with post-COVID myocarditis. The COVID-19 diagnosis was confirmed for all patients. Median time to seeking medical care after COVID-19 was 4 [3; 7] months. The diagnosis of myocarditis was confirmed by magnetic resonance imaging (MRI) of the heart (n=10) and by endomyocardial biopsy of the right ventricle (n=6). The virus was detected in the myocardium with PCR; immunohistochemical (IHC) study with antibody to SARS-Cov-2 was performed; anticardiac antibody level was measured; and echocardiography and Holter monitoring were performed. Hemodynamically significant coronary atherosclerosis was excluded for all patients older than 40 years.Results    All patients showed a clear connection between the emergence or exacerbation of cardiac symptoms and COVID-19. 11 patients did not have any signs of heart disease before COVID-19; 4 patients had previously had moderate arrhythmia or heart failure (HF) without myocarditis. Symptoms of myocarditis emerged at 1-5 months following COVID-19. MRI revealed typical late gadolinium accumulation, signs of hyperemia, and one case of edema. The level of anticardiac antibodies was increased 3-4 times in 73 % больных. Two major clinical variants of post-COVID myocarditis were observed. 1. Arrhythmic (n=6), with newly developed extrasystole or atrial fibrillation without systolic dysfunction. 2. Decompensated variant with systolic dysfunction and biventricular HF (n=9). Mean left ventricular ejection fraction was 34.1±7.8 %, and left ventricular end-diastolic dimension was 5.8±0.7 cm. In one case, myocarditis was associated with signs of IgG4‑negative aortitis. SARS-Cov-2 RNA was found in 5 of 6 biopsy samples of the myocardium. The longest duration of SARS-Cov-2 persistence in the myocardium was 9 months following COVID-19. By using antibody to the Spike antigen and nucleocapsid, SARS-Cov-2 was detected in cardiomyocytes, endothelium, and macrophages. Five patients were diagnosed with lymphocytic myocarditis; one with giant-cell myocarditis; three patients had signs of endocarditis (infectious, lymphocytic with mural thrombosis).Conclusion    Subacute/chronic post-COVID myocarditis with isolated arrhythmias or systolic dysfunction is characterized by long-term (up to 9 months) persistence of SARS-Cov-2 in the myocardium in combination with a high immune activity. Endocarditis can manifest either as infectious or as nonbacterial thromboendocarditis. A possibility of using corticosteroids and anticoagulants in the treatment of post-COVID myoendocarditis should be studied.

Anti-heart antibodies levels and their correlation with clinical symptoms and outcomes in patients with confirmed or suspected diagnosis COVID-19

The aim of this study is to evaluate the blood level of anti-heart antibodies (AHA) and its correlation with clinical outcomes in patients with severe and moderate coronavirus disease 2019 (COVID-19). The study included 34 patients (23 males; mean age 60.2 ± 16.6 years) with COVID-19 pneumonia. Besides standard medical examination, the AHA blood levels were observed, including antinuclear antibodies, antiendothelial cell antibodies, anti-cardiomyocyte antibodies (AbC), anti-smooth muscle antibodies (ASMA), and cardiac conducting tissue antibodies. Median hospital length of stay was 14 [13; 18] days. AHA levels were increased in 25 (73.5%) patients. Significant correlation (p < 0.05) of AHA levels with cardiovascular manifestations (r = 0.459) was found. AbC levels correlated with pneumonia severity (r = 0.472), respiratory failure (r = 0.387), need for invasive ventilation (r = 0.469), chest pain (r = 0.374), low QRS voltage (r = 0.415), and levels of C-reactive protein (r = 0.360) and lactate dehydrogenase (r = 0.360). ASMA levels were found to correlate with atrial fibrillation (r = 0.414, p < 0.05). Antinuclear antibodies and AbC levels correlated with pericardial effusion (r = 0.721 and r = 0.745, respectively, p < 0.05). The lethality rate was 8.8%. AbC and ASMA levels correlated significantly with lethality (r = 0.363 and r = 0.426, respectively, p < 0.05) and were prognostically important. AHA can be considered as part of the systemic immune and inflammatory response in COVID-19. Its possible role in the inflammatory heart disease requires further investigation.

COVID-19 and Toll-Like Receptor 4 (TLR4): SARS-CoV-2 May Bind and Activate TLR4 to Increase ACE2 Expression, Facilitating Entry and Causing Hyperinflammation

Causes of mortality from COVID-19 include respiratory failure, heart failure, and sepsis/multiorgan failure. TLR4 is an innate immune receptor on the cell surface that recognizes pathogen-associated molecular patterns (PAMPs) including viral proteins and triggers the production of type I interferons and proinflammatory cytokines to combat infection. It is expressed on both immune cells and tissue-resident cells. ACE2, the reported entry receptor for SARS-CoV-2, is only present on ~1-2% of the cells in the lungs or has a low pulmonary expression, and recently, the spike protein has been proposed to have the strongest protein-protein interaction with TLR4. Here, we review and connect evidence for SARS-CoV-1 and SARS-CoV-2 having direct and indirect binding to TLR4, together with other viral precedents, which when combined shed light on the COVID-19 pathophysiological puzzle. We propose a model in which the SARS-CoV-2 spike glycoprotein binds TLR4 and activates TLR4 signalling to increase cell surface expression of ACE2 facilitating entry. SARS-CoV-2 also destroys the type II alveolar cells that secrete pulmonary surfactants, which normally decrease the air/tissue surface tension and block TLR4 in the lungs thus promoting ARDS and inflammation. Furthermore, SARS-CoV-2-induced myocarditis and multiple-organ injury may be due to TLR4 activation, aberrant TLR4 signalling, and hyperinflammation in COVID-19 patients. Therefore, TLR4 contributes significantly to the pathogenesis of SARS-CoV-2, and its overactivation causes a prolonged or excessive innate immune response. TLR4 appears to be a promising therapeutic target in COVID-19, and since TLR4 antagonists have been previously trialled in sepsis and in other antiviral contexts, we propose the clinical trial testing of TLR4 antagonists in the treatment of severe COVID-19. Also, ongoing clinical trials of pulmonary surfactants in COVID-19 hold promise since they also block TLR4.

Anticardiac antibodies in patients with severe and moderate COVID-19 (correlations with the clinical performance and prognosis)

The level and significance of anticardiac antibodies (ACA) in patients with COVID-19 infection have not yet been studied.Aim. To assess the level of various ACA in patients with severe and moderate COVID-19 infection and to identify the correlation of antibody profile with the clinical performance and prognosis.Material and methods. The study included 86 (38 women and 48 men) patients aged 20-90 years (60,2±16,6 years) who were hospitalized for moderate and severe COVID-19 infection in April-June 2020. Nasopharyngeal swab confirmed the disease in 59,3% of patients. In addition to the standard examination, electrocardiography and chest scan, level of antinuclear antibodies (ANA), antiendothelial cell antibodies (AECA), anti-cardiomyocyte antibodies, antibodies to anti-smooth muscles (ASMA) and cardiac conduction system fibers. Echocardiography was performed in 17 patients. Mean length of stay was 14 [12; 18] days. Death was considered as the primary endpoint.Results. Prevalence of heart disease and symptoms (including hypertension and coronary artery disease) was 45,3%. The manifestations of coronavirus heart damage include arrhythmias (supraventricular premature beats, 3,6%; atrial fibrillation, 9,3%), heart failure (9,3%), low QRS voltage (11,4%), repolarization abnormalities (41,9%), pericardial effusion (30%). An increase in troponin levels was observed in low number of patients. All types of cardiovascular disease correlated with the maximum D-dimer level (AUC, 0,752, p<0,01). Titers of two or more types of ACA were increased by 3 or more times in 25 (73,5%) patients. Significant (p<0,05) correlations of ANA level with cardiovascular symptoms/diseases in general (r=0,459), anti-cardiomyocyte antibodies — with the prevalence of pneumonia (r=0,472), shortness of breath severity (r=0,370), respiratory failure (r=0,387), oxygen therapy (r=0,388) and mechanical ventilation (r=0,469), as well as the presence of chest pain (r=0,374), QRS voltage decrease (r=0,415), maximum level of CRP (r=0,360) and LDH (r=0,360). ANA and anti-cardiomyocyte antibody levels strongly correlated with pericardial effusion (r=0,721 and r=0,745, respectively, p<0,05). The mortality rate was 9,3%. Heart failure was one of the death causes in 37,5%. The level of anti-cardiomyocyte antibodies and ASMA correlated with mortality (r=0,363, and r=0,426, p<0,05) and had a predictive value. Mortality in patients with cardiovascular disease was 17,9%, without — 2,2% (p<0,05). The most powerful predictive model for COVID-19 adverse outcomes includes age, diabetes, oxygen therapy extent, maximum leukocyte, C-reactive protein and D-dimer levels. However, a model that includes only age, diabetes, and cardiovascular disease also has sufficient predictive power (correlation coefficient, 0,568, p<0,001).Conclusion. An increase in ACA titers was detected in 73,5% of patients, correlated with mortality, in most cases reflects the general activity and severity of the disease and can be regarded as part of response in COVID-19. At the same time, a direct correlation with signs of myocardial damage, the presence and volume of pericardial effusion confirms the direct role of ACA in the development of myopericarditis.

COVID-19 Pneumonia in Patients with Chronic Myocarditis (HBV-Associated with InfarctLike Debute): Specifics of the Diseases Course, the Role of the Basic Therapy (Part II)

Chronic infectious-immune myocarditis of severe course can potentially be considered as a factor that aggravates the course of new coronavirus disease (COVID-19) and increases the risk of adverse outcomes. The interaction of chronic myocarditis and COVID-19 during long-term immunosuppressive therapy has not been studied. We present a description of a 35-year-old female patient with chronic infectious-immune myocarditis (morphologically confirmed, with a history of infarction-like onset and thromboembolic complications), who had continuous immunosuppressive therapy with methylprednisolone and mycophenolate mofetil. The patient also received new oral anticoagulants and tenofovir (for chronic HBV infection). COVID-19 (SARS-Cov-2 RNA+) was diagnosed in May 2020. Risk factors for the adverse course of coronavirus infection included severe obesity, heart failure, and life-threatening ventricular arrhythmias. Correction of immunosuppressive therapy (withdrawal of the cytostatic agent, administration of hydroxychloroquine) and therapy with levofloxacin, an interleukin-17 inhibitor (netakimab) were performed. The severity of pneumonia and respiratory failure was moderate despite high fever and high levels of inflammatory markers in the blood (including interleukin-6). Signs of exacerbation of myocarditis, increased levels of troponin T and anticardial antibodies (compared with the initial ones) were not found. It can be assumed that supportive immunosuppressive therapy for myocarditis has a positive effect on the course of coronavirus pneumonia and avoids exacerbation of myocarditis. Careful continuation of immunosuppressive therapy with temporary withdrawal of aggressive cytostatics can be recommended in chronic myocarditis. Further study of the features of the course of previous myocarditis and COVID-19 pneumonia is necessary.