Endothelial Dysfunction in COVID-19: Lessons Learned from Coronaviruses

Genetic Susceptibility in Endothelial Injury Syndromes after Hematopoietic Cell Transplantation and Other Cellular Therapies: Climbing a Steep Hill

Hematopoietic stem cell transplantation (HSCT) remains a cornerstone in the management of patients with hematological malignancies. Endothelial injury syndromes, such as HSCT-associated thrombotic microangiopathy (HSCT-TMA), veno-occlusive disease/sinusoidal obstruction syndrome (SOS/VOD), and capillary leak syndrome (CLS), constitute complications after HSCT. Moreover, endothelial damage is prevalent after immunotherapy with chimeric antigen receptor-T (CAR-T) and can be manifested with cytokine release syndrome (CRS) or immune effector cell-associated neurotoxicity syndrome (ICANS). Our literature review aims to investigate the genetic susceptibility in endothelial injury syndromes after HSCT and CAR-T cell therapy. Variations in complement pathway- and endothelial function-related genes have been associated with the development of HSCT-TMA. In these genes, CFHR5, CFHR1, CFHR3, CFI, ADAMTS13, CFB, C3, C4, C5, and MASP1 are included. Thus, patients with these variations might have a predisposition to complement activation, which is also exaggerated by other factors (such as acute graft-versus-host disease, infections, and calcineurin inhibitors). Few studies have examined the genetic susceptibility to SOS/VOD syndrome, and the implicated genes include CFH, methylenetetrahydrofolate reductase, and heparinase. Finally, specific mutations have been associated with the onset of CRS (PFKFB4, CX3CR1) and ICANS (PPM1D, DNMT3A, TE2, ASXL1). More research is essential in this field to achieve better outcomes for our patients.

Viral Pneumonia: From Influenza to COVID-19

Respiratory viruses are increasingly recognized as a cause of community-acquired pneumonia (CAP). The implementation of new diagnostic technologies has facilitated their identification, especially in vulnerable population such as immunocompromised and elderly patients and those with severe cases of pneumonia. In terms of severity and outcomes, viral pneumonia caused by influenza viruses appears similar to that caused by non-influenza viruses. Although several respiratory viruses may cause CAP, antiviral therapy is available only in cases of CAP caused by influenza virus or respiratory syncytial virus. Currently, evidence-based supportive care is key to managing severe viral pneumonia. We discuss the evidence surrounding epidemiology, diagnosis, management, treatment, and prevention of viral pneumonia.

Prognosis of COVID-19 severity using DERGA, a novel machine learning algorithm

It is important to determine the risk for admission to the intensive care unit (ICU) in patients with COVID-19 presenting at the emergency department. Using artificial neural networks, we propose a new Data Ensemble Refinement Greedy Algorithm (DERGA) based on 15 easily accessible hematological indices. A database of 1596 patients with COVID-19 was used; it was divided into 1257 training datasets (80 % of the database) for training the algorithms and 339 testing datasets (20 % of the database) to check the reliability of the algorithms. The optimal combination of hematological indicators that gives the best prediction consists of only four hematological indicators as follows: neutrophil-to-lymphocyte ratio (NLR), lactate dehydrogenase, ferritin, and albumin. The best prediction corresponds to a particularly high accuracy of 97.12 %. In conclusion, our novel approach provides a robust model based only on basic hematological parameters for predicting the risk for ICU admission and optimize COVID-19 patient management in the clinical practice.

Unraveling Links between Chronic Inflammation and Long COVID: Workshop Report

As COVID-19 continues, an increasing number of patients develop long COVID symptoms varying in severity that last for weeks, months, or longer. Symptoms commonly include lingering loss of smell and taste, hearing loss, extreme fatigue, and "brain fog." Still, persistent cardiovascular and respiratory problems, muscle weakness, and neurologic issues have also been documented. A major problem is the lack of clear guidelines for diagnosing long COVID. Although some studies suggest that long COVID is due to prolonged inflammation after SARS-CoV-2 infection, the underlying mechanisms remain unclear. The broad range of COVID-19's bodily effects and responses after initial viral infection are also poorly understood. This workshop brought together multidisciplinary experts to showcase and discuss the latest research on long COVID and chronic inflammation that might be associated with the persistent sequelae following COVID-19 infection.

Microvascular Dysfunction in COVID-19 Patients with Acute Coronary Syndrome

Objective

Coronavirus disease 2019 (COVID-19) is considered to deteriorate endothelial function through hyperinflammation. We aimed to investigate microvascular dysfunction using the angiographic parameters thrombolysis in myocardial infarction frame count (TFC) and myocardial blush grade (MBG), in COVID-19 patients with acute coronary syndrome (ACS).

Methods

One hundred and sixty-five patients presented with ACS (62.4% ST elevated myocardial infarction) and underwent percutaneous coronary intervention between March 1 and June 30, 2020, were enrolled in the study. The polymerase chain reaction test was performed in case of suggestive symptoms or typical computerized tomography findings.

Results

Twenty-six patients (15.7%) were tested positive for COVID-19. Significantly higher values were observed in TFC in patients with COVID-19 (p<0.001), whereas COVID-19 patients had significantly lower MBGs (Grade 0 and 1) (p<0.001). Peak troponin-I value was also higher in the COVID-19 group (27335 vs. 15959 ng/dL, p=0.006). Mortality risk was higher in COVID-19 patients (38.4% vs. 7.2%, p<0.001). TFC and ejection fraction may predict in-hospital mortality among COVID-19 patients with ACS according to logistic regression results. In correlation analysis, TFC correlated positively with C-reactive protein (r=0.340, p<0.001) and peak troponin-I value (r=0.369, p<0.001).

Conclusion

COVID-19 is associated with slow coronary flow and microvascular impairment in ACS.

Distinct Features of Vascular Diseases in COVID-19

The Coronavirus Disease 2019 (COVID-19) pandemic was declared in early 2020 after several unexplained pneumonia cases were first reported in Wuhan, China, and subsequently in other parts of the world. Commonly, the disease comprises several clinical features, including high temperature, dry cough, shortness of breath, and hypoxia, associated with findings of interstitial pneumonia on chest X-ray and computer tomography. Nevertheless, severe forms of acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) are not limited to the respiratory tract but also may be extended to other systems, including the cardiovascular system. The bi-directional relationship between atherosclerosis and COVID-19 is accompanied by poor prognosis. The immune response hyperactivation due to SARS-CoV-2 infection causes an increased secretion of cytokines, endothelial dysfunction, and arterial stiffness, which promotes the development of atherosclerosis. Also, due to the COVID-19 pandemic, access to healthcare amenities was reduced, resulting in increased morbidity and mortality in patients at risk. Furthermore, as lockdown measures were largely adopted worldwide, the sedentary lifestyle and the increased consumption of processed nutrients or unhealthy food increased, and in the consequence, we might observe even 70% of overweight and obese population. Altogether, with the relatively low ratio of vaccinated people in many countries, and important health debt appeared, which is now and will be for next decade a large healthcare challenge. However, the experience gained in the COVID-19 pandemic and the new methods of patients' approaching have helped the medical system to overcome this crisis and will hopefully help in the case of new possible epidemics.

Long-term hypercoagulability, endotheliopathy and inflammation following acute SARS-CoV-2 infection

INTRODUCTION

both symptomatic and asymptomatic SARS-CoV-2 infections - coined Coronavirus disease 2019 (COVID-19) - have been linked to a higher risk of cardiovascular events after recovery.

AREAS COVERED

our review aims to summarize the latest evidence on the increased thrombotic and cardiovascular risk in recovered COVID-19 patients and to examine the pathophysiological mechanisms underlying the interplay among endothelial dysfunction, inflammatory response and coagulation in long-COVID. We performed a systematic search of studies on hypercoagulability, endothelial dysfunction and inflammation after SARS-CoV-2 infection.

EXPERT OPINION

endothelial dysfunction is a major pathophysiological mechanism responsible for most clinical manifestations in COVID-19. The pathological activation of endothelial cells by a virus infection results in a pro-adhesive and chemokine-secreting phenotype, which in turn promotes the recruitment of circulating leukocytes. Cardiovascular events after COVID-19 appear to be related to persistent immune dysregulation. Patients with long-lasting symptoms display higher amounts of proinflammatory molecules such as tumor necrosis factor-α, interferon γ and interleukins 2 and 6. Immune dysregulation can trigger the activation of the coagulation pathway. The formation of extensive microclots in vivo, both during acute COVID-19 and in long-COVID-19, appears to be a relevant mechanism responsible for persistent symptoms and cardiovascular events.

Role of endothelial cells and angiotensin converting enzyme-II in COVID-19 and brain damages post-infection

Severe acute respiratory syndrome coronavirus 2 (SARS CoV-2) causes coronavirus disease 2019 (COVID-19), which became a pandemic in late 2019 and early 2020. Apart from many other symptoms of this infection, such as loss of smell and taste, rashes, body aches, fatigue, and psychological and cardiac symptoms, it also causes vasodilation in response to inflammation via nitric oxide release. SARS CoV-2 affects microcirculation, resulting in the swelling and damage of endothelial cells, micro thrombosis, constriction of capillaries, and damage to pericytes that are vital for the integrity of capillaries, angiogenesis, and the healing process. Cytokine storming has been associated with COVID-19 illness. Capillary damage and congestion may cause limited diffusion exchange of oxygen in the lungs and hence hypoxemia and tissue hypoxia occur. This perspective study will explore the involvement of capillary damage and inflammation by their interference with blood and tissue oxygenation as well as brain function in the persistent symptoms and severity of COVID-19. The overall effects of capillary damage due to COVID-19, microvascular damage, and hypoxia in vital organs are also discussed in this perspective. Once initiated, this vicious cycle causes inflammation due to hypoxia, resulting in limited capillary function, which in turn causes inflammation and tissue damage. Low oxygen levels and high cytokines in brain tissue may lead to brain damage. The after-effects may be in the form of psychological symptoms such as mood changes, anxiety, depression, and many others that need to be investigated.

Unpacking the Complexity of COVID-19 Fatalities: Adverse Events as Contributing Factors-A Single-Center, Retrospective Analysis of the First Two Years of the Pandemic

In a retrospective analysis of 477 fatal COVID-19 cases hospitalised at a single medical centre during the period from 6 March 2020 to 30 June 2022, several factors defining those patients at admission were assessed, as well as the course of the hospitalisation and factors contributing to death. There was a predominance of men (59.3% (283)) burdened by comorbidities, with increased inflammation at admission. Patients aged ≥ 81 years were significantly more likely to be admitted to and die in infectious diseases units (IDU) due to respiratory failure, their hospital stays were shorter, and they were most likely not to receive specialist treatment. The most common COVID-19 complications included acute kidney injury in 31.2% (149) patients and thromboembolic complications in 23.5% (112). The course of hospitalisation was complicated by healthcare-associated infections (HAI) in 33.3% (159) of cases, more often in those treated with baricitinib (p < 0.001). The initial use of an antibiotic, although common (94.8% (452)), was unwarranted in almost half of the cases (47.6% (215)). Complications of hospitalisation (46.1% (220)) and adverse events involving staff (49.7% (237)) were found in almost half of the patients. In 88.7% (423) of the cases, death was due to respiratory failure in the course of SARS-CoV-2 infection. Adverse events during hospitalisation should be considered as an additional factor that, in addition to the infection itself, may have influenced the death of patients.

High level of lactate dehydrogenase and ischaemia-reperfusion injury regulate the multiple organ dysfunction in patients with COVID-19

BACKGROUND

Multiple organ damage has been observed in patients with COVID-19, but the exact pathway is not known. Vital organs of the human body may get affected after replication of SARS-CoV-2, including the lungs, heart, kidneys, liver and brain. It triggers severe inflammation and impairs the function of two or more organ systems. Ischaemia-reperfusion (IR) injury is a phenomenon that can have disastrous effects on the human body.

METHODS

In this study, we analysed the laboratory data of 7052 hospitalised patients with COVID-19 including lactate dehydrogenase (LDH). A total of 66.4% patients were men and 33.6% were women, which indicated gender difference as a prominent factor to be considered.

RESULTS

Our data showed high levels of inflammation and elevated markers of tissue injury from multiple organs C reactive protein, white blood cell count, alanine transaminase, aspartate aminotransferase and LDH. The number of red blood cells, haemoglobin concentration and haematocrit were lower than normal which indicated a reduction in oxygen supply and anaemia.

CONCLUSION

On the basis of these results, we proposed a model linking IR injury to multiple organ damage by SARS-CoV-2. COVID-19 may cause a reduction in oxygen towards an organ, which leads to IR injury.

COVID-19 and the cardiovascular system: a study of pathophysiology and interpopulation variability

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in humans can lead to various degrees of tissue and organ damage, of which cardiovascular system diseases are one of the main manifestations, such as myocarditis, myocardial infarction, and arrhythmia, which threaten the infected population worldwide. These diseases threaten the cardiovascular health of infected populations worldwide. Although the prevalence of coronavirus disease 2019 (COVID-19) has slightly improved with virus mutation and population vaccination, chronic infection, post-infection sequelae, and post-infection severe disease patients still exist, and it is still relevant to study the mechanisms linking COVID-19 to cardiovascular disease (CVD). This article introduces the pathophysiological mechanism of COVID-19-mediated cardiovascular disease and analyzes the mechanism and recent progress of the interaction between SARS-CoV-2 and the cardiovascular system from the roles of angiotensin-converting enzyme 2 (ACE2), cellular and molecular mechanisms, endothelial dysfunction, insulin resistance, iron homeostasis imbalance, and psychosocial factors, respectively. We also discussed the differences and mechanisms involved in cardiovascular system diseases combined with neocoronavirus infection in different populations and provided a theoretical basis for better disease prevention and management.

Discontinuation of Antihypertensive Drug Use Compared to Continuation in COVID-19 Patients: A Systematic Review with Meta-analysis and Trial Sequential Analysis

INTRODUCTION

COVID-19 related mortality is about 2%, and it increases with comorbidities, like hypertension. Regarding management, there is debatable evidence about the benefits of continuation vs. discontinuation of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers (ACEI/ARB).

AIM

We performed a systematic review to assess the effects and safety of in-hospital discontinuation compared to continuation of ACEI/ARB in COVID-19 patients.

METHODS

We systematically searched on PubMed, Scopus, and EMBASE from inception to June 19, 2021. We included observational studies and trials that compared the effects and safety of continuing ACEI/ARB compared to discontinuing it in COVID-19 patients. Effects sizes for dichotomous variables were expressed as risk ratios (RR) and 95% confidence intervals. For continuous variables, effects were expressed as mean difference (MD). We used random effect models with the inverse variance method. We assessed certainty of evidence using the GRADE approach.

RESULTS

We included three open-label randomized controlled trials and five cohort studies. We found that the continuation group had lower risk of death compared with the discontinuation group only in the cohort group (RR: 0.46, 95% CI: 0.24-0.90), but not in the RCT group (RR: 1.22, 95% CI: 0.75-2.00). The ICU admission rate was significantly lower in the continuation group (RR: 0.46, 95% CI: 0.31-0.68) in the cohort group, but not in RCT group (RR: 1.03, 95% CI: 0.67-1.59). We did not find significant differences between groups regarding hospitalization length, hypotension, AKI needing renal replacement therapy, mechanical ventilation, new or worsening heart failure, myocarditis, renal replacement therapy, arrhythmias, thromboembolic events and SOFA AUC. The GRADE approach revealed that the certainty ranged from moderate to high level.

CONCLUSIONS

There is no significant difference in mortality and other outcomes between continuation and discontinuation groups.

Neurological damages in COVID-19 patients: Mechanisms and preventive interventions

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel coronavirus, causes coronavirus disease 2019 (COVID-19) which led to neurological damage and increased mortality worldwide in its second and third waves. It is associated with systemic inflammation, myocardial infarction, neurological illness including ischemic strokes (e.g., cardiac and cerebral ischemia), and even death through multi-organ failure. At the early stage, the virus infects the lung epithelial cells and is slowly transmitted to the other organs including the gastrointestinal tract, blood vessels, kidneys, heart, and brain. The neurological effect of the virus is mainly due to hypoxia-driven reactive oxygen species (ROS) and generated cytokine storm. Internalization of SARS-CoV-2 triggers ROS production and modulation of the immunological cascade which ultimately initiates the hypercoagulable state and vascular thrombosis. Suppression of immunological machinery and inhibition of ROS play an important role in neurological disturbances. So, COVID-19 associated damage to the central nervous system, patients need special care to prevent multi-organ failure at later stages of disease progression. Here in this review, we are selectively discussing these issues and possible antioxidant-based prevention therapies for COVID-19-associated neurological damage that leads to multi-organ failure.

Cholinergic dysfunction in COVID-19: frantic search and hoping for the best

A novel coronavirus known as severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) is a potential cause of acute respiratory infection called coronavirus disease 2019 (COVID-19). The binding of SARS-CoV-2 with angiotensin-converting enzyme 2 (ACE2) induces a series of inflammatory cellular events with cytopathic effects leading to cell injury and hyperinflammation. Severe SARS-CoV-2 infection may lead to dysautonomia and sympathetic storm due to dysfunction of the autonomic nervous system (ANS). Therefore, this review aimed to elucidate the critical role of the cholinergic system (CS) in SARS-CoV-2 infection. The CS forms a multi-faceted network performing diverse functions in the body due to its distribution in the neuronal and non-neuronal cells. Acetylcholine (ACh) acts on two main types of receptors which are nicotinic receptors (NRs) and muscarinic receptors (MRs). NRs induce T cell anergy with impairment of antigen-mediated signal transduction. Nicotine through activation of T cell NRs inhibits the expression and release of the pro-inflammatory cytokines. NRs play important anti-inflammatory effects while MRs promote inflammation by inducing the release of pro-inflammatory cytokines. SARS-CoV-2 infection can affect the morphological and functional stability of CS through the disruption of cholinergic receptors. SARS-CoV-2 spike protein is similar to neurotoxins, which can bind to nicotinic acetylcholine receptors (nAChR) in the ANS and brain. Therefore, cholinergic receptors mainly nAChR and related cholinergic agonists may affect the pathogenesis of SARS-CoV-2 infection. Cholinergic dysfunction in COVID-19 is due to dysregulation of nAChR by SARS-CoV-2 promoting the central sympathetic drive with the development of the sympathetic storm. As well, nAChR activators through interaction with diverse signaling pathways can reduce the risk of inflammatory disorders in COVID-19. In addition, nAChR activators may mitigate endothelial dysfunction (ED), oxidative stress (OS), and associated coagulopathy in COVID-19. Similarly, nAChR activators may improve OS, inflammatory changes, and cytokine storm in COVID-19. Therefore, nAChR activators like varenicline in virtue of its anti-inflammatory and anti-oxidant effects with direct anti-SARS-CoV-2 effect could be effective in the management of COVID-19.

Flavonoids as a therapeutical option for the treatment of thrombotic complications associated with COVID-19

The SARS-CoV-2 outbreak has been one of the largest public health crises globally, while thrombotic complications have emerged as an important factor contributing to mortality. Therefore, compounds that regulate the processes involved in thrombosis could represent a dietary strategy to prevent thrombotic complications involved in COVID-19. In August 2022, various databases were consulted using the keywords "flavonoids", "antiplatelet", "anticoagulant", "fibrinolytic", and "nitric oxide". Studies conducted between 2019 and 2022 were chosen. Flavonoids, at concentrations mainly between 2 and 300 μM, are capable of regulating platelet aggregation, blood coagulation, fibrinolysis, and nitric oxide production due to their action on multiple receptors and enzymes. Most of the studies have been carried out through in vitro and in silico models, and limited studies have reported the in vivo and clinical effect of flavonoids. Currently, quercetin has been the only flavonoid evaluated clinically in patients with COVID-19 for its effect on D-dimer levels. Therefore, clinical studies in COVID-19 patients analyzing the effect on platelet, coagulant, fibrinolytic, and nitric oxide parameters are required. In addition, further high-quality studies that consider cytotoxic safety and bioavailability are required to firmly propose flavonoids as a treatment for the thrombotic complications implicated in COVID-19.

Use of Intravenous Vitamin C in Critically Ill Patients With COVID-19 Infection

INTRODUCTION

The pathophysiology for Coronavirus Disease 2019 (COVID-19) infection is characterized by cytokine oxidative stress and endothelial dysfunction. Intravenous (IV) vitamin C has been utilized as adjuvant therapy in critically ill patients with sepsis for its protective effects against reactive oxygen species and immunomodulatory effects. The primary objective of this study was to evaluate the effects of IV vitamin C in critically ill patients with COVID-19 infection.

METHODS

Retrospective observational cohort study with propensity score matching of intensive care unit (ICU) patients who received 1.5 grams IV vitamin C every 6 hours for up to 4 days for COVID-19 infection. The primary study outcome was in-hospital mortality. Secondary outcomes included vasopressor requirements in norepinephrine equivalents, ICU length of stay, and change in Sequential Organ Failure Assessment (SOFA) score.

RESULTS

Eight patients received IV vitamin C and were matched to 24 patients. Patients in the IV vitamin C group had higher rates of hospital mortality [7 (88%) vs. 19 (79%), P = 0.049]. There was no difference in the daily vasopressor requirement in the treatment group or between the 2 groups. The mean SOFA scores post-treatment was higher in the IV vitamin C group (12.4 ± 2.8 vs. 8.1 ± 3.5, P < 0.005). There was no difference in ICU length of stay between the treatment and control groups.

CONCLUSION

Adjunctive IV vitamin C for the management of COVID-19 infection in critically ill patients may not decrease the incidence of mortality, vasopressor requirements, SOFA scores, or ventilator settings.

The D405N Mutation in the Spike Protein of SARS-CoV-2 Omicron BA.5 Inhibits Spike/Integrins Interaction and Viral Infection of Human Lung Microvascular Endothelial Cells

Severe COVID-19 is characterized by angiogenic features, such as intussusceptive angiogenesis, endothelialitis, and activation of procoagulant pathways. This pathological state can be ascribed to a direct SARS-CoV-2 infection of human lung ECs. Recently, we showed the capability of SARS-CoV-2 to infect ACE2-negative primary human lung microvascular endothelial cells (HL-mECs). This occurred through the interaction of an Arg-Gly-Asp (RGD) motif, endowed on the Spike protein at position 403-405, with α_vβ₃ integrin expressed on HL-mECs. HL-mEC infection promoted the remodeling of cells toward a pro-inflammatory and pro-angiogenic phenotype. The RGD motif is distinctive of SARS-CoV-2 Spike proteins up to the Omicron BA.1 subvariant. Suddenly, a dominant D405N mutation was expressed on the Spike of the most recently emerged Omicron BA.2, BA.4, and BA.5 subvariants. Here we demonstrate that the D405N mutation inhibits Omicron BA.5 infection of HL-mECs and their dysfunction because of the lack of Spike/integrins interaction. The key role of ECs in SARS-CoV-2 pathogenesis has been definitively proven. Evidence of mutations retrieving the capability of SARS-CoV-2 to infect HL-mECs highlights a new scenario for patients infected with the newly emerged SARS-CoV-2 Omicron subvariants, suggesting that they may display less severe disease manifestations than those observed with previous variants.

Recognizing risk factors associated with poor outcomes among patients with COVID-19

The coronavirus disease 2019 (COVID-19) pandemic has affected >610 million people globally, exerting major social, economic, and health impacts. Despite the large number of global casualities and severe symptomatology associated with COVID-19, a large number of individuals remain at elevated risk of infection and severe outcomes related to poor lifestyle behaviors and/or associated comorbidities. Beyond the well-known social distance and masking policies, maintaining an active lifestyle, minimizing the consumption of tobacco products, and maintaining an adequate nutrition status are some of the key factors that, in an affordable and accessible way, have the potential to improve health and minimize COVID-19 impact. In addition, bringing awareness of the higher risks and poor prognosis of COVID-19 when other conditions are present seems to be essential to protect those individuals with the highest risks.

Early prediction of COVID-19 outcome using artificial intelligence techniques and only five laboratory indices

We aimed to develop a prediction model for intensive care unit (ICU) hospitalization of Coronavirus disease-19 (COVID-19) patients using artificial neural networks (ANN). We assessed 25 laboratory parameters at first from 248 consecutive adult COVID-19 patients for database creation, training, and development of ANN models. We developed a new alpha-index to assess association of each parameter with outcome. We used 166 records for training of computational simulations (training), 41 for documentation of computational simulations (validation), and 41 for reliability check of computational simulations (testing). The first five laboratory indices ranked by importance were Neutrophil-to-lymphocyte ratio, Lactate Dehydrogenase, Fibrinogen, Albumin, and D-Dimers. The best ANN based on these indices achieved accuracy 95.97%, precision 90.63%, sensitivity 93.55%. and F1-score 92.06%, verified in the validation cohort. Our preliminary findings reveal for the first time an ANN to predict ICU hospitalization accurately and early, using only 5 easily accessible laboratory indices.

Respiratory viruses: their importance and lessons learned from COVID-19

Respiratory virus infection can cause severe illnesses capable of inducing acute respiratory failure that can progress rapidly to acute respiratory distress syndrome (ARDS). ARDS is related to poor outcomes, especially in individuals with a higher risk of infection, such as the elderly and those with comorbidities, i.e. obesity, asthma, diabetes mellitus and chronic respiratory or cardiovascular disease. Despite this, effective antiviral treatments available for severe viral lung infections are scarce. The coronavirus disease 2019 (COVID-19) pandemic demonstrated that there is also a need to understand the role of airborne transmission of respiratory viruses. Robust evidence supporting this exists, but better comprehension could help implement adequate measures to mitigate respiratory viral infections. In severe viral lung infections, early diagnosis, risk stratification and prognosis are essential in managing patients. Biomarkers can provide reliable, timely and accessible information possibly helpful for clinicians in managing severe lung viral infections. Although respiratory viruses highly impact global health, more research is needed to improve care and prognosis of severe lung viral infections. In this review, we discuss the epidemiology, diagnosis, clinical characteristics, management and prognosis of patients with severe infections due to respiratory viruses.

COVID-19 and the heart

BACKGROUND

There is evidence for a bi-directional relationship between COVID-19 and the cardiovascular (CV) system.

SOURCE OF DATA

Published literature.

AREAS OF AGREEMENT

Pre-existing heart failure (HF) increases the risk of mortality with COVID-19. CV complications are recognized, including increased rates of acute coronary syndromes, HF, arrhythmia and myocarditis. Drugs targeting the angiotensin system are safe and may provide prognostic benefit.

AREAS OF CONTROVERSY

Vaccination as a cause of myocarditis remains a key area of contention.

GROWING POINTS

As the pandemic progresses, we are gaining more data about the long-term effects of COVID-19 on the CV system: long COVID, and medium-to-long-term increases in CV risk.

AREAS TIMELY FOR DEVELOPING RESEARCH

Large-scale longitudinal studies will shed light on long-term CV outcomes with COVID-19. Furthermore, the differential effects of COVID-19 variants on the CV system must be investigated.

Association of Vitamin C Treatment with Clinical Outcomes for COVID-19 Patients: A Systematic Review and Meta-Analysis

Background: Vitamin C is an essential nutrient that serves as an antioxidant and is known to reduce the inflammatory response associated with pneumonia and acute respiratory distress syndrome in patients with the coronavirus disease (COVID-19), but its clinical effects remain controversial. Methods: This study aimed to investigate the therapeutic effect of vitamin C administration on the clinical outcomes of COVID-19 patients through a systematic review and meta-analysis. Results: Nineteen studies were selected, of which 949 participants administered vitamin C were in the intervention group, and 1816 participants were in the control group. All-cause mortality, hospitalization duration, length of intensive care unit stay, and ventilation incidence in COVID-19 patients were analyzed. The intervention group tends to have a lower risk ratio (RR = 0.81, 95% CI: 0.62 to 1.07; I2 = 58%; Q = 40.95; p < 0.01) in all-cause mortality than the control group. However, there were no significant differences in ventilation incidence, hospitalization duration, and length of ICU stay between the two groups. In the subgroup analysis for all-cause mortality, the risk ratio for RCT as study design, combination therapy, of vitamin C was lower than that of the combination therapy with other agents. A moderate dosage showed a lower RR than a higher dose. Conclusion: The results suggest that vitamin C may lower mortality in COVID-19 patients, but further large-scale studies are required to assess the role of vitamin C in the treatment of COVID-19.

Circulating Serum Cystatin C as an Independent Risk Biomarker for Vascular Endothelial Dysfunction in Patients with COVID-19-Associated Multisystem Inflammatory Syndrome in Children (MIS-C): A Prospective Observational Study

INTRODUCTION

Multisystem inflammatory syndrome in children (MIS-C) is a new clinical entity that has emerged in the context of the COVID-19 pandemic. Despite the less severe course of the disease, varying degrees of cardiovascular events may occur in MIS-C; however, data on vascular changes occurring in MIS-C are still lacking. Endothelial dysfunction (ED) is thought to be one of the key risk factors contributing to MIS-C.

BACKGROUND

We conducted a prospective observational study. We investigated possible manifestations of cardiac and endothelial involvement in MIS-C after the treatment of the acute stage and potential predictive biomarkers in patients with MIS-C.

METHODS

Twenty-seven consecutive pediatric subjects (≥9 years), at least three months post-treated MIS-C of varying severity, in a stable condition, and twenty-three age- and sex-matched healthy individuals (HI), were enrolled. A combined non-invasive diagnostic approach was used to assess endothelial function as well as markers of organ damage using cardiac examination and measurement of the reactive hyperemia index (RHI), by recording the post- to pre-occlusion pulsatile volume changes and biomarkers related to ED and cardiac disease.

RESULTS

MIS-C patients exhibited a significantly lower RHI (indicative of more severe ED) than those in HI (1.32 vs. 1.80; p = 0.001). The cutoff of RHI ≤ 1.4 was independently associated with a higher cardiovascular risk. Age and biomarkers significantly correlated with RHI, while serum cystatin C (Cys C) levels were independently associated with a diminished RHI, suggesting Cys C as a surrogate marker of ED in MIS-C.

CONCLUSIONS

Patients after MIS-C display evidence of ED, as shown by a diminished RHI and altered endothelial biomarkers. Cys C was identified as an independent indicator for the development of cardiovascular disease. The combination of these factors has the potential to better predict the cardiovascular consequences of MIS-C. Our study suggests that ED may be implicated in the pathophysiology of this disease.

Long-term assessment of systemic microcirculatory function and plasma cytokines after coronavirus disease 2019 (COVID-19)

Systemic microvascular dysfunction has been shown to be present in COVID-19, and serum cytokines are known to be involved in the regulation of vascular function. We sought to evaluate systemic microvascular endothelial function, with laser doppler perfusion monitoring (LDPM), and plasma levels of cytokines after acute COVID-19. Individuals admitted to a Cardiology hospital with acute COVID-19 and followed for 12-15 months after recovery underwent noninvasive evaluation of systemic endothelium-dependent microvascular reactivity by cutaneous LDPM with local thermal hyperemia (LTH). A multiplex biometric immunoassay panel was used to assess 48 serum cytokines and chemokines. Twenty patients and 14 control volunteers were enrolled. The areas under the curves of vasodilation induced by LTH were significantly increased after recovery (P=0.009) and were not different from values obtained in healthy volunteers (P = 0.85). The peak microvascular flow during LTH did also significantly increase (P = 0.02), and was not different form values obtained in healthy volunteers (P = 0.55). Several cytokines displayed significantly reduced serum concentrations after recovery from COVID-19. In conclusion, endothelium-dependent systemic microvascular reactivity improved after recovery from COVID-19 in patients with cardiovascular diseases, in parallel with a reduction in the levels of several serum cytokines and chemokines involved in the regulation of vascular function and inflammation.

SARS-CoV-2 spike protein induces endothelial dysfunction in 3D engineered vascular networks

With new daily discoveries about the long-term impacts of COVID-19 there is a clear need to develop in vitro models that can be used to better understand the pathogenicity and impact of COVID-19. Here we demonstrate the utility of developing a model of endothelial dysfunction that utilizes induced pluripotent stem cell-derived endothelial progenitors encapsulated in collagen hydrogels to study the effects of COVID-19 on the endothelium. We found that treating these cell-laden hydrogels with SARS-CoV-2 spike protein resulted in a significant decrease in the number of vessel-forming cells as well as vessel network connectivity. Following treatment with the anti-inflammatory drug dexamethasone, we were able to prevent SARS-CoV-2 spike protein-induced endothelial dysfunction. In addition, we confirmed release of inflammatory cytokines associated with the COVID-19 cytokine storm. In conclusion, we have demonstrated that even in the absence of immune cells, we are able to use this 3D in vitro model for angiogenesis to reproduce COVID-19 induced endothelial dysfunction seen in clinical settings.

T Lymphocyte-Derived Exosomes Transport MEK1/2 and ERK1/2 and Induce NOX4-Dependent Oxidative Stress in Cardiac Microvascular Endothelial Cells

Background

Activation of endothelial cells by inflammatory mediators secreted by CD4⁺ T lymphocytes plays a key role in the inflammatory response. Exosomes represent a specific class of signaling cues transporting a mixture of proteins, nucleic acids, and other biomolecules. So far, the impact of exosomes shed by T lymphocytes on cardiac endothelial cells remained unknown.

Methods and Results

Supernatants of CD4⁺ T cells activated with anti-CD3/CD28 beads were used to isolate exosomes by differential centrifugation. Activation of CD4⁺ T cells enhanced exosome production, and these exosomes (CD4-exosomes) induced oxidative stress in cardiac microvascular endothelial cells (cMVECs) without affecting their adhesive properties. Furthermore, CD4-exosome treatment aggravated the generation of mitochondrial reactive oxygen species (ROS), reduced nitric oxide (NO) levels, and enhanced the proliferation of cMVECs. These effects were reversed by adding the antioxidant apocynin. On the molecular level, CD4-exosomes increased NOX2, NOX4, ERK1/2, and MEK1/2 in cMVECs, and ERK1/2 and MEK1/2 proteins were found in CD4-exosomes. Inhibition of either MEK/ERK with U0126 or ERK with FR180204 successfully protected cMVECs from increased ROS levels and reduced NO bioavailability. Treatment with NOX1/4 inhibitor GKT136901 effectively blocked excessive ROS and superoxide production, reversed impaired NO levels, and reversed enhanced cMVEC proliferation triggered by CD4-exosomes. The siRNA-mediated silencing of Nox4 in cMVECs confirmed the key role of NOX4 in CD4-exosome-induced oxidative stress. To address the properties of exosomes under inflammatory conditions, we used the mouse model of CD4⁺ T cell-dependent experimental autoimmune myocarditis. In contrast to exosomes obtained from control hearts, exosomes obtained from inflamed hearts upregulated NOX2, NOX4, ERK1/2, MEK1/2, increased ROS and superoxide levels, and reduced NO bioavailability in treated cMVECs, and these changes were reversed by apocynin.

Conclusion

Our results point to exosomes as a novel class of bioactive factors secreted by CD4⁺ T cells in immune response and represent potential important triggers of NOX4-dependent endothelial dysfunction. Neutralization of the prooxidative aspect of CD4-exosomes could open perspectives for the development of new therapeutic strategies in inflammatory cardiovascular diseases.

SARS-CoV-2 induced hepatic injuries and liver complications

Background

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), which is resilient, highly pathogenic, and rapidly transmissible. COVID-19 patients have been reported to have underlying chronic liver abnormalities linked to hepatic dysfunction.

Discussion

Viral RNAs are detectable in fecal samples by RT-PCR even after negative respiratory samples, which suggests that SARS-CoV-2 can affect the gastrointestinal tract and the liver. The case fatality rates are higher among the elderly and those with underlying comorbidities such as hypertension, diabetes, liver abnormality, and heart disease. There is insufficient research on signaling pathways. Identification of molecular mechanisms involved in SARS-CoV-2-induced damages to hepatocytes is challenging. Herein, we demonstrated the multifactorial effects of SARS-CoV-2 on liver injury such as psychological stress, immunopathogenesis, systemic inflammation, ischemia and hypoxia, drug toxicity, antibody-dependent enhancement (ADE) of infection, and several others which can significantly damage the liver.

Conclusion

During the COVID-19 pandemic, it is necessary for clinicians across the globe to pay attention to SARS-CoV-2-mediated liver injury to manage the rising burden of hepatocellular carcinoma. To face the challenges during the resumption of clinical services for patients with pre-existing liver abnormalities and HCC, the impact of SARS-CoV-2 on hepatocytes should be investigated both in vitro and in vivo.

Comparison of Angiographic and Clinical Outcomes After Primary Percutaneous Coronary Intervention for ST-elevation Myocardial Infarction Between Patients With and Without Concomitant COVID-19 Infection

OBJECTIVE

COVID-19 infection can involve the cardiovascular system and worsen the prognosis of the patients. This study aimed to investigate the adverse effects of COVID-19 on angiographic and clinical outcomes of primary percutaneous coronary intervention (PCI) in patients with acute ST-elevation MI and compare results with those patients without COVID-19 disease.

METHODS

The study was a retrospective observational cohort, in which patients presented with ST-elevation MI from February 2020 to April 2021, treated with primary PCI were divided into 2 groups based on the COVID-19 infection. Then, the procedural and angiographic indices and also clinical outcomes were compared between the 2 groups.

RESULTS

A total of 1150 patients were enrolled in the study. Those with established COVID-19 infection had worse baseline thrombolysis in myocardial infarction flow grade and also were at higher risk for worse procedural outcomes such as lower thrombolysis in myocardial infarction frame count, myocardial blush grade, and slow-flow coronary disease, after the primary PCI. Additionally, the presence of COVID-19 at the time of primary PCI was related to a significantly higher duration of hospitalization and in-hospital mortality. Given the potential impact of other factors on outcomes, analysis for all of the primary endpoints was done again after adjustment of these factors and the results were the same as before, suggesting the independent effect of COVID-19 infection.

CONCLUSIONS

The concomitant COVID-19 infection in the patients undergoing primary PCI is associated with significantly worse angiographic, procedural and clinical outcomes. Surprisingly, this finding is regardless of patients' baseline risk factors and demographical characteristics.

Impact of high-dose vitamin C on the mortality, severity, and duration of hospital stay in COVID-19 patients: A meta-analysis

Background and Aims

Vitamin C has been predicted to be effective as an antioxidant in treating various ailments, including viral infections such as pervasive coronavirus disease (COVID-19). With this meta-analysis, we looked to ascertain the relationship between high-dose vitamin C administration and mortality, severity, and length of hospitalization of COVID-19 patients.

Methods

We collected articles from PubMed, Google Scholar, ScienceDirect, SAGE, and Cochrane databases between January 1, 2020, and May 30, 2022. Odds ratio (ORs) with corresponding 95% confidence interval (CI) and p value were calculated to assess the connection of high-dose vitamin C in COVID-19 patients' mortality and severity. The length of hospitalization was calculated and pooled with the mean difference (MD), 95% CI, and p value. Review manager 5.3 was used to carry out this meta-analysis.

Results

This meta-analysis included 15 complete studies involving 2125 COVID-19 patients. Our study demonstrated a significant correlation between vitamin C consumption and death. Vitamin C consumption significantly reduces mortality risk with COVID-19 patients (OR = 0.54, 95% CI = 0.42-0.69, p < 0.00001). Furthermore, there was a link between the severity of COVID-19 and the intake of vitamin C. Patients who consumed vitamin C showed 0.63 times less severity than those who did not take vitamin C (OR = 0.63, 95% CI = 0.43-0.94, p = 0.02). Patients taking vitamin C spent slightly more time in hospital than those who did not take vitamin C (MD = 0.19, 95% CI = -1.57 to 1.96, p = 0.83).

Conclusions

During COVID-19, there was a substantial advantage in taking supplementary vitamin C, at least in terms of severity and mortality.

Predictors of Long COVID in Patients without Comorbidities: Data from the Polish Long-COVID Cardiovascular (PoLoCOV-CVD) Study

Background: The SARS-CoV-2 pandemic has become an enormous worldwide challenge over the last two years. However, little is still known about the risk of Long COVID (LC) in patients without comorbidities. Thus, we aimed to assess the predictors of LC in patients without comorbidities. Methods: Patients’ information, the course of the disease with symptoms, and post-COVID-19 complaints were collected within 4−12 weeks after COVID-19 recovery. Next, the patients were followed for at least 3 months. ECG, 24-h ECG monitoring, 24-h blood pressure (BP) monitoring, echocardiography, and selected biochemical tests were performed. LC was recognized based on the WHO definition. Results: We identified 701 consecutive patients, 488 of whom completed a 3-month follow-up (63% women). Comparisons were made between the LC group (n = 218) and patients without any symptoms after SARS-CoV-2 recovery (non-LC group) (n = 270). Patients with a severe course of acute-phase COVID-19 developed LC complications more often (34% vs. 19%, p < 0.0001). The persistent symptoms were observed in 45% of LC patients. The LC group also had significantly more symptoms during the acute phase of COVID-19, and they suffered significantly more often from dyspnoea (48 vs. 33%), fatigue (72 vs. 63%), chest pain (50 vs. 36%), leg muscle pain (41 vs. 32%), headache (66 vs. 52%), arthralgia (44 vs. 25%), and chills (34 vs. 25%). In LC patients, significant differences regarding sex and body mass index were observed—woman: 69% vs. 56% (p = 0.003), and BMI: 28 [24−31] vs. 26 kg/m2 [23−30] (p < 0.001), respectively. The number of symptoms in the acute phase was significantly greater in the LC group than in the control group (5 [2−8] vs. 2 [1−5], p = 0.0001). The LC group also had a higher 24-h heart rate (77 [72−83] vs. 75 [70−81], p = 0.021) at admission to the outpatient clinic. Multivariate regression analysis showed that LC patients had a higher BMI (odds ratio (OR): 1.06, 95% confidence intervals [CI]: 1.02−1.10, p = 0.007), almost twice as often had a severe course of COVID-19 (OR: 1.74, CI: 1.07−2.81, p = 0.025), and presented with joint pain in the acute phase (OR: 1.90, CI: 1.23−2.95, p = 0.004). Conclusions: A severe course of COVID-19, BMI, and arthralgia are independently associated with the risk of Long COVID in healthy individuals.

A case report of cerebral venous sinus thrombosis presenting with rapidly progressive dementia

Background

Cerebral venous sinus thrombosis (CVST) is a rare but serious and treatable cause of neurologic symptoms. Due to the variable clinical presentation, CVST was often misdiagnosed. According to published case reports, common clinical manifestations of CVST include headache, focal neurological deficit, epilepsy, papilledema, etc. It is rare, nevertheless, to mention cases of rapidly progressive dementia (RPD).

Case presentation

We reported a case of a 62-year-old retired male accountant, a Han Chinese from eastern China, who initially presented with slow response and memory decline. Until 2 months later, his memory declined and slow response deteriorated significantly, and he could not even complete simple tasks like brushing his teeth, washing his face, washing his feet, and dressing himself, and sometimes developed fecal incontinence. His neuropsychological test demonstrated severe cognitive decline. The cerebrospinal fluid (CSF) studies revealed markedly high opening pressure (260 mm of water), and coagulation tests indicated a mild elevation of D-Dimer of 1.19 mg/L. The magnetic resonance venography (MRV) showed thrombosis of the left transverse sinus, sigmoid sinus, and jugular venous bulb and was diagnosed as CVST. He switched from subcutaneous low molecular weight heparin (LMWH) and transitioned to oral anticoagulants at the time of discharge. The repeated CSF studies revealed normal opening pressure. After 5 days of anticoagulant treatment, his symptoms considerably improved, and a 1-month follow-up revealed that he had fully healed with no signs of recurrence.

Conclusion

This case demonstrated the clinical heterogeneity of CVST, which should be taken into account for differential diagnosis of RPD. This case study also offered fresh data for the categorization of the clinical traits and the diagnosis of CVST.

Antithrombotic and antiplatelet effects of plant-derived compounds: a great utility potential for primary, secondary, and tertiary care in the framework of 3P medicine

Thromboembolism is the third leading vascular disease, with a high annual incidence of 1 to 2 cases per 1000 individuals within the general population. The broader term venous thromboembolism generally refers to deep vein thrombosis, pulmonary embolism, and/or a combination of both. Therefore, thromboembolism can affect both – the central and peripheral veins. Arterial thromboembolism causes systemic ischemia by disturbing blood flow and oxygen supply to organs, tissues, and cells causing, therefore, apoptosis and/or necrosis in the affected tissues. Currently applied antithrombotic drugs used, e.g. to protect affected individuals against ischemic stroke, demonstrate significant limitations. For example, platelet inhibitors possess only moderate efficacy. On the other hand, thrombolytics and anticoagulants significantly increase hemorrhage. Contextually, new approaches are extensively under consideration to develop next-generation antithrombotics with improved efficacy and more personalized and targeted application. To this end, phytochemicals show potent antithrombotic efficacy demonstrated in numerous in vitro, ex vivo, and in vivo models as well as in clinical evaluations conducted on healthy individuals and persons at high risk of thrombotic events, such as pregnant women (primary care), cancer, and COVID-19-affected patients (secondary and tertiary care). Here, we hypothesized that specific antithrombotic and antiplatelet effects of plant-derived compounds might be of great clinical utility in primary, secondary, and tertiary care. To increase the efficacy, precise patient stratification based on predictive diagnostics is essential for targeted protection and treatments tailored to the person in the framework of 3P medicine. Contextually, this paper aims at critical review toward the involvement of specific classes of phytochemicals in antiplatelet and anticoagulation adapted to clinical needs. The paper exemplifies selected plant-derived drugs, plant extracts, and whole plant foods/herbs demonstrating their specific antithrombotic, antiplatelet, and fibrinolytic activities relevant for primary, secondary, and tertiary care. One of the examples considered is antithrombotic and antiplatelet protection specifically relevant for COVID-19-affected patient groups.

Fenofibrate for COVID-19 and related complications as an approach to improve treatment outcomes: the missed key for Holy Grail

Introduction

Fenofibrate is an agonist of peroxisome proliferator activated receptor alpha (PPAR-α), that possesses anti-inflammatory, antioxidant, and anti-thrombotic properties. Fenofibrate is effective against a variety of viral infections and different inflammatory disorders. Therefore, the aim of critical review was to overview the potential role of fenofibrate in the pathogenesis of SARS-CoV-2 and related complications.

Results

By destabilizing SARS-CoV-2 spike protein and preventing it from binding angiotensin-converting enzyme 2 (ACE2), a receptor for SARS-CoV-2 entry, fenofibrate can reduce SARS-CoV-2 entry in human cells Fenofibrate also suppresses inflammatory signaling pathways, which decreases SARS-CoV-2 infection-related inflammatory alterations. In conclusion, fenofibrate anti-inflammatory, antioxidant, and antithrombotic capabilities may help to minimize the inflammatory and thrombotic consequences associated with SARSCoV-2 infection. Through attenuating the interaction between SARS-CoV-2 and ACE2, fenofibrate can directly reduce the risk of SARS-CoV-2 infection.

Conclusions

As a result, fenofibrate could be a potential treatment approach for COVID-19 control.

The mechanistic basis linking cytokine storm to thrombosis in COVID-19

It is now well established that infection with SARS-CoV-2 resulting in COVID-19 disease includes a severely symptomatic subset of patients in whom an aggressive and/or dysregulated host immune response leads to cytokine storm syndrome (CSS) that may be further complicated by thrombotic events, contributing to the severe morbidity and mortality observed in COVID-19. This review provides a brief overview of cytokine storm in COVID-19, and then presents a mechanistic discussion of how cytokine storm affects integrated pathways in thrombosis involving the endothelium, platelets, the coagulation cascade, eicosanoids, auto-antibody mediated thrombosis, and the fibrinolytic system.

The Effect of Statins on Clinical Outcome Among Hospitalized Patients With COVID-19: A Multi-Centric Cohort Study

The coronavirus disease-2019 (COVID-19) is caused by SARS-CoV-2, leading to acute respiratory distress syndrome (ARDS), thrombotic complications, and myocardial injury. Statins, prescribed for lipid reduction, have anti-inflammatory, anti-thrombotic, and immunomodulatory properties and are associated with reduced mortality rates in COVID-19 patients. Our goal was to investigate the beneficial effects of statins in hospitalized COVID-19 patients admitted to three multi-specialty hospitals in India from 1 June 2020, to 30 April 2021. This retrospective study included 1,626 patients, of which 524 (32.2%) were antecedent statin users among 768 patients (384 statin users, 384 non-statin users) identified with 1:1 propensity-score matching. We established a multivariable logistic regression model to identify the patients’ demographics and adjust the baseline clinical and laboratory characteristics and co-morbidities. Statin users showed a lower mean of white blood cell count (7.6 × 10³/µL vs. 8.1 × 10³/µL, p < 0.01), and C-reactive protein (100 mg/L vs. 120.7 mg/L, p < 0.001) compared to non-statin COVID-19 patients. The same positive results followed in lipid profiles for patients on statins. Cox proportional-hazards regression models evaluated the association between statin use and mortality rate. The primary endpoint involved mortality during the hospital stay. Statin use was associated with lower odds of mortality in the propensity-matched cohort (OR 0.52, 95% CI 0.33-0.64, p < 0.001). These results support the previous evidence of the beneficial effects of statins in reducing mortality in hospitalized COVID-19 patients.

EASIX, Modified EASIX and Simplified EASIX as an Early Predictor for Intensive Care Unit Admission and Mortality in Severe COVID-19 Patients

COVID-19 receives a lot of attention due to its threat to global public health. Research is ongoing to find universal methods to assess the baseline health status of a patient to determine prognosis and management strategies. This study aims to assess the predictive potential of the EASIX (Endothelial Activation and Stress Index) and two of its modifications (mEASIX and sEASIX) in terms of the need for admission to the ICU (intensive care unit), the use of IMV (invasive mechanical ventilation) and death due to COVID-19. The medical data of 370 severely ill patients hospitalised in the COVID-19 departments of the Regional Specialist Hospital in Wroclaw (Poland), including the ICU, were analysed retrospectively. The mortality rate in the group studied was 65.7% (243 cases). In the case of all three indices, EASIX, mEASIX and sEASIX, there was a statistically significant correlation between the need for admission to the ICU (p = 0.026, p = 0.019, p = 0.001, respectively) and the risk of death (p < 0.001). In terms of the risk of death, the high values of the assessed indices (EASIX ≥ 2.36, mEASIX ≥ 704.03, sEASIX ≥ 3.81) were characterised by low sensitivity (≤40%), high specificity (approximately 90%) and low NPV (negative predictive value) (approximately 40%) with high PPV (positive predictive value) (approximately 80%). Due to the ease of implementation and the low cost of performing basic laboratory tests, the above-mentioned indices can be used as an additional, but not universal tool for the initial assessment of the health condition of patients admitted to the hospital.

Association of Obesity With COVID-19 Severity and Mortality: An Updated Systemic Review, Meta-Analysis, and Meta-Regression

Background

Obesity affects the course of critical illnesses. We aimed to estimate the association of obesity with the severity and mortality in coronavirus disease 2019 (COVID-19) patients.

Data Sources

A systematic search was conducted from the inception of the COVID-19 pandemic through to 13 October 2021, on databases including Medline (PubMed), Embase, Science Web, and Cochrane Central Controlled Trials Registry. Preprint servers such as BioRxiv, MedRxiv, ChemRxiv, and SSRN were also scanned.

Study Selection and Data Extraction

Full-length articles focusing on the association of obesity and outcome in COVID-19 patients were included. Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines were used for study selection and data extraction. Our Population of interest were COVID-19 positive patients, obesity is our Intervention/Exposure point, Comparators are Non-obese vs obese patients The chief outcome of the study was the severity of the confirmed COVID-19 positive hospitalized patients in terms of admission to the intensive care unit (ICU) or the requirement of invasive mechanical ventilation/intubation with obesity. All-cause mortality in COVID-19 positive hospitalized patients with obesity was the secondary outcome of the study.

Results

In total, 3,140,413 patients from 167 studies were included in the study. Obesity was associated with an increased risk of severe disease (RR=1.52, 95% CI 1.41-1.63, p<0.001, I2 = 97%). Similarly, high mortality was observed in obese patients (RR=1.09, 95% CI 1.02-1.16, p=0.006, I2 = 97%). In multivariate meta-regression on severity, the covariate of the female gender, pulmonary disease, diabetes, older age, cardiovascular diseases, and hypertension was found to be significant and explained R2 = 40% of the between-study heterogeneity for severity. The aforementioned covariates were found to be significant for mortality as well, and these covariates collectively explained R2 = 50% of the between-study variability for mortality.

Conclusions

Our findings suggest that obesity is significantly associated with increased severity and higher mortality among COVID-19 patients. Therefore, the inclusion of obesity or its surrogate body mass index in prognostic scores and improvement of guidelines for patient care management is recommended.

Radial Peripapillary Capillary Plexus Perfusion and Endothelial Dysfunction in Early Post-SARS-CoV-2 Infection

Background: Endothelial cells damage and thromboinflammation are considered key elements in the generation of organ impairment in patients with COVID-19 disease. The endothelial function is evaluated by measuring flow-mediated dilation (FMD). We aimed to analyze the association between FMD impairment and retinal vascular parameters in early post-COVID-19 patients. 00118-00199Tomography (OCT), OCT Angiography (OCTA) and slit lamp examination were performed. FMD ≤ 7% was considered as pathological. Our primary outcome was to assess potential differences in the radial peripapillary capillary plexus flow index (RPCP-FI) and RPCP density (RPCP-D) values between post-COVID-19 patients with and without FMD impairment. The associations of other retinal vascular parameters with FMD impairment were assessed as secondary endpoints. Results: FMD impairment was detected in 31 patients (37.8%). RPCP-FI (p = 0.047), age (p = 0.048) and prevalence of diabetes (p = 0.046) significantly differed in patients with FMD ≤ 7% in regression analysis. RPCP-FI was linearly correlated with FMD values (R = 0.244, p =0.027). SCT was found to be lower in patients with impaired FMD (p = 0.004), although this difference was only a trend in binary logistic regression output (p = 0.07). Conclusions: Early post-COVID-19 patients showed a higher prevalence of FMD impairment compared to the general population. Age, diabetes and RPCP-FI were independently correlated with the presence of endothelial impairment in the early post-infective period.

Histamine Potentiates SARS-CoV-2 Spike Protein Entry Into Endothelial Cells

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which causes coronavirus disease (COVID-19) is one of the most serious global health crises in recent history. COVID-19 patient symptoms range from life-threatening to mild and asymptomatic, which presents unique problems in identifying, quarantining, and treating the affected individuals. The emergence of unusual symptoms among survivors, now referred to as “Long COVID”, is concerning, especially since much about the condition and the treatment of it is still relatively unknown. Evidence so far also suggests that some of these symptoms can be attributed to vascular inflammation. Although famotidine, the commonly used histamine H2 receptor (H2R) blocker, was shown to have no antiviral activity, recent reports indicate that it could prevent adverse outcomes in COVID-19 patients. Histamine is a classic proinflammatory mediator, the levels of which increase along with other cytokines during COVID-19 infection. Histamine activates H2R signaling, while famotidine specifically blocks H2R activation. Investigating the effects of recombinant SARS-CoV-2 spike protein S1 Receptor-Binding Domain (Spike) on ACE2 expression in cultured human coronary artery endothelial cells, we found that the presence of histamine potentiated spike-mediated ACE2 internalization into endothelial cells. This effect was blocked by famotidine, protein kinase A inhibition, or by H2 receptor protein knockdown. Together, these results indicate that histamine and histamine receptor signaling is likely essential for spike protein to induce ACE2 internalization in endothelial cells and cause endothelial dysfunction and that this effect can be blocked by the H2R blocker, famotidine.

Functional ACE2 deficiency leading to angiotensin imbalance in the pathophysiology of COVID-19

SARS-CoV-2, the virus responsible for COVID-19, uses angiotensin converting enzyme 2 (ACE2) as its primary cell-surface receptor. ACE2 is a key enzyme in the counter-regulatory pathway of the broader renin-angiotensin system (RAS) that has been implicated in a broad array of human pathology. The RAS is composed of two competing pathways that work in opposition to each other: the "conventional" arm involving angiotensin converting enzyme (ACE) generating angiotensin-2 and the more recently identified ACE2 pathway that generates angiotensin (1-7). Following the original SARS pandemic, additional studies suggested that coronaviral binding to ACE2 resulted in downregulation of the membrane-bound enzyme. Given the similarities between the two viruses, many have posited a similar process with SARS-CoV-2. Proponents of this ACE2 deficiency model argue that downregulation of ACE2 limits its enzymatic function, thereby skewing the delicate balance between the two competing arms of the RAS. In this review we critically examine this model. The available data remain incomplete but are consistent with the possibility that the broad multisystem dysfunction of COVID-19 is due in large part to functional ACE2 deficiency leading to angiotensin imbalance with consequent immune dysregulation and endothelial cell dysfunction.

Anti-COVID-19 Potential of Azadirachta indica (Neem) Leaf Extract

COVID-19 is caused by infection with the “severe acute respiratory syndrome coronavirus-2″ (i.e., SARS-CoV-2). This is an enveloped virus having a positive sense, single-stranded RNA genome; like the two earlier viruses SARS-CoV and the Middle East respiratory syndrome (MERS) virus. COVID-19 is unique in that, in the severe case, it has the propensity to affect multiple organs, leading to multiple organ distress syndrome (MODS), and causing high morbidity and mortality in the extreme case. In addition, comorbidities like age, cardiovascular disease, diabetes and its complications, obesity, are risk factors for severe COVID-19. It turns out that a most plausible, simple, single explanation for this propensity for MODS is the pivotal involvement of the vascular endothelium (VE). This is a consequence of the fact that the VE seamlessly connects all the entire vascular bed in the body, thus linking all the target organs (heart, lungs, kidney, liver, brain) and systems. Infection with SARS-CoV-2 leads to hyper-inflammation yielding uncontrolled production of a mixture of cytokines, chemokines, reactive oxygen species, nitric oxide, oxidative stress, acute phase proteins (e.g., C-reactive protein), and other pro-inflammatory substances. In the extreme case, a cytokine storm is created. Displacement of the virus bound to the VE, and/or inhibition of binding of the virus, would constitute an effective strategy for preventing COVID-19. In this regard, the acetone-water extract of the leaf of the Neem (Azadirachta indica) plant has been known to prevent the adherence of malaria parasitized red blood cells (pRBCs) to VE; prevent cytoadherence of cancer cells in metastasis; and prevent HIV from invading target T lymphocytes. We therefore hypothesize that this Neem leaf acetone-water extract will prevent the binding of SARS-CoV-2 to the VE, and therefore be an effective therapeutic formulation against COVID-19. It is therefore advocated herein that this extract be investigated through rigorous clinical trials for this purpose. It has the advantages of being (i) readily available, and renewable in favor of the populations positioned to benefit from it; (ii) simple to prepare; and (iii) devoid of any detectable toxicity.

Vascular Dysfunction and Its Cardiovascular Consequences During and After COVID-19 Infection: A Narrative Review

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory coronavirus 2 (SARS-CoV2) has brought out changes in our daily life and has caused severe morbidity and mortality across the globe. Especially, post covid complications may remain a threat to the patient’s life. It may also increase the burden on existing health infrastructure and the country’s economy. This disease affects the respiratory system and other organ systems of the body, such as the cardiovascular system. The aim of the present narrative review is to understand how COVID-19 infection deranges vascular homeostasis, leading to endothelial dysfunction and arterial stiffness in the acute phase and following infection. To this effect, definite keywords were employed to obtain relevant information using PubMed database and Google Scholar search engines. It was documented that preexisting cardiovascular disease enhances morbidity in COVID-19 patients. Moreover, an elevated risk of development of new onset cardiovascular events has also been reported. Even a small amount of myocardial injury was significantly associated with death. The presence of virus in myocardial cells has also been documented. Furthermore, endothelial dysfunction and arterial stiffness were documented in the acute phase and 3–4 weeks to 4 months after COVID infection. The virus enters endothelial cells by binding with ACE2 “receptor” on its surface and deranges cellular machinery. It results in reduced conversion of Ang II to Ang (1–7). Accumulated Ang II then activates PI3K-Akt signaling pathway and regulates endothelial activation and production of IL-6 and reactive oxygen species (ROS). An imbalance between renin angiotensin aldosterone system (RAAS) and kallikrein kinin system (KKS) also occurs, which may cause endothelial dysfunction. It is understandable that the underlying pathophysiology of this altered arterial stiffness is multifactorial, involving various cellular and immunological biomolecules.

COVID-19-Associated Endothelial Dysfunction and Microvascular Injury: From Pathophysiology to Clinical Manifestations

Coronavirus-19 disease (COVID-19) affects more people than previous coronavirus infections and has a higher mortality. Higher incidence and mortality can probably be explained by COVID-19 causative agent's greater affinity (about 10-20 times) for angiotensin-converting enzyme 2 (ACE2) receptor compared with other coronaviruses. Here, the authors first summarize clinical manifestations, then present symptoms of COVID-19 and the pathophysiological mechanisms underlying specific organ/system disease. The worse clinical outcome observed in COVID-19 patients with diabetes may be in part related to the increased ADAM17 activity and its unbalanced interplay with ACE2. Therefore, strategies aimed to inhibit ADAM17 activity may be explored to develop new effective therapeutic approaches.

The Association Between the Use of Statins and Clinical Outcomes in Patients with COVID-19: A Systematic Review and Meta-analysis

Purpose

Previously, we have reported potential clinical benefits with the use of statins in patients with coronavirus disease 2019 (COVID-19) in a meta-analysis, where there was a significantly reduced hazard for a fatal or severe course of illness with the use of statins, but the meta-analysis was limited by the small number of studies included, with small heterogeneity among studies, due to the unavailability of more studies at the point of literature search. We aimed to perform an updated systematic review and meta-analysis to summarize the existing evidence on the effect of statins on the clinical outcomes of patients with COVID-19.

Methods

Electronic databases, including PubMed, Google Scholar, and Scopus, and preprint servers were searched (last updated June 3, 2021) to identify studies investigating the association between the use of statins in patients with COVID-19 and the development of severe disease and/or mortality. Random-effects model meta-analyses were performed to estimate the pooled odds ratio (OR) or hazard ratio (HR) with 95% confidence intervals (CIs). The outcomes of interest were (1) all-cause mortality and (2) a composite endpoint of severe illness of COVID-19.

Results

Upon systematic literature search, we identified 35 studies, of which 32 studies reported the outcome of all-cause mortality and 15 studies reported the composite endpoint of severe COVID-19 illness between statin users versus non-statin users with COVID-19. Our meta-analysis revealed that the use of statins was associated with a significantly lower risks of all-cause mortality (HR = 0.70, 95% CI 0.58–0.84, n = 21,127, and OR = 0.63, 95% CI 0.51–0.79, n = 115,097) and the composite endpoint of severe illness (OR = 0.80, 95% CI 0.73–0.88, n = 10,081) in patients with COVID-19, compared to non-use of statins, at the current sample size.

Conclusion

Statin use is associated with a better prognosis in patients with COVID-19. Our findings provide a rationale to investigate the use of statins among patients with COVID-19 in large scale clinical trials.

Intravenous vitamin C use and risk of severity and mortality in COVID-19: A systematic review and meta-analysis

The administration of intravenous vitamin C (IV-VC) in treating patients with coronavirus disease 2019 (COVID-19) is still highly controversial. There have been no previous studies on the effect of IV-VC on the severity and mortality of COVID-19. Hence, we conducted a systematic review and meta-analysis to compare the disease severity and mortality in patients with COVID-19 who promptly received IV-VC treatment vs those who did not. We performed a comprehensive systematic search of seven health science databases, including PubMed, Embase, Cochrane Library, MEDLINE, Web of Science, China National Knowledge Infrastructure, and Wanfang Data, up to June 23, 2021. We identified a total of seven related articles, which were included in this study. This meta-analysis showed that IV-VC treatment did not affect disease severity compared with placebo treatment or usual care (odds ratio [OR], 0.70; 95% CI, 0.45 to 1.07; P = 0.10). In addition, no statistically significant difference in mortality was observed between patients who received IV-VC treatment and those who did not (OR, 0.64; 95% CI, 0.41 to 1.00; P = 0.05). Moreover, the adjusted meta-analysis revealed that the use of IV-VC did not influence disease severity (OR, 0.67; 95% CI, 0.34 to 1.31; P = 0.242) or mortality (OR, 1.02; 95% CI, 0.75 to 1.40; P = 0.877) in comparison with a control group. The results of this meta-analysis demonstrated that short-term IV-VC treatment did not reduce the risk of severity and mortality in patients with COVID-19.

Antibody profiles in COVID ‐19 convalescent plasma prepared with Amotosalen/ UVA pathogen reduction treatment

Background

COVID‐19 convalescent plasma (CCP), from donors recovered from severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) infection, is one of the limited therapeutic options currently available for the treatment of critically ill patients with COVID‐19. There is growing evidence that CCP may reduce viral loads and disease severity; and reduce mortality. However, concerns about the risk of transfusion‐transmitted infections (TTI) and other complications associated with transfusion of plasma, remain. Amotosalen/UVA pathogen reduction treatment (A/UVA‐PRT) of plasma offers a mitigation of TTI risk, and when combined with pooling has the potential to increase the diversity of the polyclonal SARS‐CoV‐2 neutralizing antibodies.

Study design and methods

This study assessed the impact of A/UVA‐PRT on SARS‐CoV‐2 antibodies in 42 CCP using multiple complimentary assays including antigen binding, neutralizing, and epitope microarrays. Other mediators of CCP efficacy were also assessed.

Results

A/UVA‐PRT did not negatively impact antibodies to SARS‐CoV‐2 and other viral epitopes, had no impact on neutralizing activity or other potential mediators of CCP efficacy. Finally, immune cross‐reactivity with other coronavirus antigens was observed raising the potential for neutralizing activity against other emergent coronaviruses.

Conclusion

The findings of this study support the selection of effective CCP combined with the use of A/UVA‐PRT in the production of CCP for patients with COVID‐19.

Acute Vertigo After COVID-19 Vaccination: Case Series and Literature Review

Objective: The aim of this study was to present some cases of acute vertigo potentially related to the coronavirus disease 2019 (COVID-19) vaccine and review the available literature about cochleovestibular dysfunction after the COVID-19 vaccination.

Methods: In the period from May to July 2021, we evaluated 33 patients (mean age 54.3 ± 14.1) with “acute vertigo” post COVID-19 vaccination. A detailed medical history was taken on comorbidities, types of vaccines received, and symptoms associated. All patients underwent otoneurological evaluation, such as head impulse test, nystagmus evaluation, test of skew (HINTS) examination. Head shaking test-induced nystagmus, hyperventilation-induced nystagmus, and parossistic positional nystagmus were studied to search for vestibular impairment.

Results: Symptoms included 16 patients (48.5%) with objective vertigo, 14 patients (42.4%) with subjective vertigo, and 3 patients (9.1%) with dizziness. Of the associated ear, nose, and throat (ENT) symptoms, the most expressed was tinnitus (18.2%). Bedside examination showed absent nystagmus in 7 patients (21.2%), 9 patients (27.3%) had horizontal or rotatory nystagmus, 17 patients (51.5%) had a vertical or oblique nystagmus, negative HST, or “central HINTS.”

Discussion and Conclusions: The 9 patients had an evoked nystagmus pathognomonic for benign paroxysmal positional vertigo; in the remaining 17 cases, peripheral vestibular dysfunction could be excluded and central disorder may be suggested. Due to the prevalence of nystagmus of non-peripheral origin, a central nervous system involvement could not be excluded. However, due to the small sample size, a definite cause–effect relationship between vaccination and vertigo cannot be inferred. In light of expected third dose, large-scale and well-designed studies are needed to better define possible adverse reactions of the COVID-19 vaccine.

Genetic prediction of ICU hospitalization and mortality in COVID‐19 patients using artificial neural networks

There is an unmet need of models for early prediction of morbidity and mortality of Coronavirus disease‐19 (COVID‐19). We aimed to a) identify complement‐related genetic variants associated with the clinical outcomes of ICU hospitalization and death, b) develop an artificial neural network (ANN) predicting these outcomes and c) validate whether complement‐related variants are associated with an impaired complement phenotype. We prospectively recruited consecutive adult patients of Caucasian origin, hospitalized due to COVID‐19. Through targeted next‐generation sequencing, we identified variants in complement factor H/CFH, CFB, CFH‐related, CFD, CD55, C3, C5, CFI, CD46, thrombomodulin/THBD, and A Disintegrin and Metalloproteinase with Thrombospondin motifs (ADAMTS13). Among 381 variants in 133 patients, we identified 5 critical variants associated with severe COVID‐19: rs2547438 (C3), rs2250656 (C3), rs1042580 (THBD), rs800292 (CFH) and rs414628 (CFHR1). Using age, gender and presence or absence of each variant, we developed an ANN predicting morbidity and mortality in 89.47% of the examined population. Furthermore, THBD and C3a levels were significantly increased in severe COVID‐19 patients and those harbouring relevant variants. Thus, we reveal for the first time an ANN accurately predicting ICU hospitalization and death in COVID‐19 patients, based on genetic variants in complement genes, age and gender. Importantly, we confirm that genetic dysregulation is associated with impaired complement phenotype.