COVID-19, ACE2, and the cardiovascular consequences

The pathophysiology of 'happy' hypoxemia in COVID-19

The novel coronavirus disease 2019 (COVID-19) pandemic is a global crisis, challenging healthcare systems worldwide. Many patients present with a remarkable disconnect in rest between profound hypoxemia yet without proportional signs of respiratory distress (i.e. happy hypoxemia) and rapid deterioration can occur. This particular clinical presentation in COVID-19 patients contrasts with the experience of physicians usually treating critically ill patients in respiratory failure and ensuring timely referral to the intensive care unit can, therefore, be challenging. A thorough understanding of the pathophysiological determinants of respiratory drive and hypoxemia may promote a more complete comprehension of a patient's clinical presentation and management. Preserved oxygen saturation despite low partial pressure of oxygen in arterial blood samples occur, due to leftward shift of the oxyhemoglobin dissociation curve induced by hypoxemia-driven hyperventilation as well as possible direct viral interactions with hemoglobin. Ventilation-perfusion mismatch, ranging from shunts to alveolar dead space ventilation, is the central hallmark and offers various therapeutic targets.

Organ-specific manifestations of COVID-19 infection

Although COVID-19 presents primarily as a lower respiratory tract infection transmitted via air droplets, increasing data suggest multiorgan involvement in patients that are infected. This systemic involvement is postulated to be mainly related to the SARS-CoV-2 virus binding on angiotensin-converting enzyme 2 (ACE2) receptors located on several different human cells. Lung involvement is the most common serious manifestation of the disease, ranging from asymptomatic disease or mild pneumonia, to severe disease associated with hypoxia, critical disease associated with shock, respiratory failure and multiorgan failure or death. Among patients with COVID-19, underlying cardiovascular comorbidities including hypertension, diabetes and especially cardiovascular disease, has been associated with adverse outcomes, whereas the emergence of cardiovascular complications, including myocardial injury, heart failure and arrhythmias, has been associated with poor survival. Gastrointestinal symptoms are also frequently encountered and may persist for several days. Haematological complications are frequent as well and have been associated with poor prognosis. Furthermore, recent studies have reported that over a third of infected patients develop a broad spectrum of neurological symptoms affecting the central nervous system, peripheral nervous system and skeletal muscles, including anosmia and ageusia. The skin, the kidneys, the liver, the endocrine organs and the eyes are also affected by the systemic COVID-19 disease. Herein, we provide a comprehensive overview of the organ-specific systemic manifestations of COVID-19.

Characteristics and outcomes of patients with COVID-19 at a district general hospital in Surrey, UK

BACKGROUND

This retrospective cohort study aims to define the clinical findings and outcomes of every patient admitted to a district general hospital in Surrey with COVID-19 in March 2020, providing a snapshot of the first wave of infection in the UK. This study is the first detailed insight into the impact of frailty markers on patient outcomes and provides the infection rate among healthcare workers.

METHODS

Data were obtained from medical records. Outcome measures were level of oxygen therapy, discharge and death. Patients were followed up until 21 April 2020.

RESULTS

108 patients were included. 34 (31%) died in hospital or were discharged for palliative care. 43% of patients aged over 65 died. The commonest comorbidities were hypertension (49; 45%) and diabetes (25; 23%). Patients who died were older (mean difference ±SEM, 13.76±3.12 years; p<0.0001) with a higher NEWS2 score (median 6, IQR 2.5-7.5 vs median 2, IQR 2-6) and worse renal function (median differences: urea 2.7 mmol/L, p<0.01; creatinine 4 μmol/L, p<0.05; eGFR 14 mL/min, p<0.05) on admission compared with survivors. Frailty markers were identified as risk factors for death. Clinical Frailty Scale (CFS) was higher in patients over 65 who died than in survivors (median 5, IQR 4-6 vs 3.5, IQR 2-5; p<0.01). Troponin and creatine kinase levels were higher in patients who died than in those who recovered (p<0.0001). Lymphopenia was common (median 0.8, IQR 0.6-1.2; p<0.005). Every patient with heart failure died (8). 26 (24%) were treated with continuous positive airway pressure (CPAP; median 3 days, IQR 2-7.3) and 9 (8%) were intubated (median 14 days, IQR 7-21). All patients who died after discharge (4; 6%) were care home residents. 276 of 699 hospital staff tested were positive for COVID-19.

CONCLUSIONS

This study identifies older patients with frailty as being particularly vulnerable and reinforces government policy to protect this group at all costs.

Angiotensin converting enzyme 2 and angiotensin (1-7) axis in pulmonary arterial hypertension

BACKGROUND

In animal models of pulmonary arterial hypertension (PAH), angiotensin-converting enzyme (ACE)2 and angiotensin (Ang)-(1-7) have been shown to have vasodilatory, antiproliferative, antifibrotic and antihypertrophic properties. However, the status and role of the ACE2-Ang(1-7) axis in human PAH is incompletely understood.

METHODS

We studied 85 patients with a diagnosis of PAH of distinct aetiologies. 55 healthy blood donors paired for age and sex served as controls. Blood samples were obtained from the pulmonary artery in patients with PAH during right heart catheterisation. Peripheral blood was obtained for both groups. Ang(1-7) and -II were measured using zone capillary electrophoresis. Aldosterone, Ang(1-9), AngA and ACE2 were measured using ELISA, and ACE2 activity was determined enzymatically.

RESULTS

Of the 85 patients, 47 had idiopathic PAH, 25 had PAH associated with congenital heart disease and 13 had PAH associated with collagen vascular disease. Compared to controls, patients with PAH had a higher concentration of AngII (median 1.03, interquartile range 0.72-1.88 pmol·mL^-1 versus 0.19, 0.10-0.37 pmol·mL^-1; p<0.001) and of aldosterone (88.7, 58.7-132 ng·dL^-1 versus 12.9, 9.55-19.9 ng·dL^-1; p<0.001). Conversely, PAH patients had a lower concentration of Ang(1-7) than controls (0.69, 0.474-0.91 pmol·mL^-1 versus 4.07, 2.82-6.73 pmol·mL^-1; p<0.001), and a lower concentration of Ang(1-9) and AngA. Similarly, the ACE2 concentration was higher than in controls (8.7, 5.35-13.2 ng·mL^-1 versus 4.53, 1.47-14.3 ng·mL^-1; p=0.011), whereas the ACE2 activity was significantly reduced (1.88, 1.08-2.81 nmol·mL^-1 versus 5.97, 3.1-17.8 nmol·mL^-1; p<0.001). No significant differences were found among the three different aetiological forms of PAH.

CONCLUSIONS

The AngII-ACE2-Ang(1-7) axis appears to be altered in human PAH and we propose that this imbalance, in favour of AngII, plays a role in the pathogenesis of the severe PAH. Further mechanistic studies are warranted.

Cancer Patients Have a Higher Risk Regarding COVID-19 - and Vice Versa?

The world is currently suffering from a pandemic which has claimed the lives of over 230,000 people to date. The responsible virus is called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and causes the coronavirus disease 2019 (COVID-19), which is mainly characterized by fever, cough and shortness of breath. In severe cases, the disease can lead to respiratory distress syndrome and septic shock, which are mostly fatal for the patient. The severity of disease progression was hypothesized to be related to an overshooting immune response and was correlated with age and comorbidities, including cancer. A lot of research has lately been focused on the pathogenesis and acute consequences of COVID-19. However, the possibility of long-term consequences caused by viral infections which has been shown for other viruses are not to be neglected. In this regard, this opinion discusses the interplay of SARS-CoV-2 infection and cancer with special focus on the inflammatory immune response and tissue damage caused by infection. We summarize the available literature on COVID-19 suggesting an increased risk for severe disease progression in cancer patients, and we discuss the possibility that SARS-CoV-2 could contribute to cancer development. We offer lines of thought to provide ideas for urgently needed studies on the potential long-term effects of SARS-CoV-2 infection.

COVID-19 and arterial hypertension: Hypothesis or evidence?

Investigations reported that hypertension, diabetes, and cardiovascular diseases were the most prevalent comorbidities among the patients with coronavirus disease 2019 (COVID-19). Hypertension appeared consistently as the most prevalent risk factors in COVID-19 patients. Some investigations speculated about the association between renin-angiotensin-aldosterone system (RAAS) and susceptibility to COVID-19, as well as the relationship between RAAS inhibitors and increased mortality in these patients. This raised concern about the potential association between hypertension (and its treatment) and propensity for COVID-19. There are only a few follow-up studies that investigated the impact of comorbidities on outcome in these patients with conflicting findings. Hypertension has been proven to be more prevalent in patients with an adverse outcome (admission in intensive care unit, use of mechanical ventilation, or death). So far, there is no study that demonstrated independent predictive value of hypertension on mortality in COVID-19 patients. There are many speculations about this coronavirus and its relation with different risk factors and underlying diseases. The aim of this review was to summarize the current knowledge about the relationship between hypertension and COVID-19 and the role of hypertension on outcome in these patients.

ACE2 (Angiotensin-Converting Enzyme 2), COVID-19, and ACE Inhibitor and Ang II (Angiotensin II) Receptor Blocker Use During the Pandemic: The Pediatric Perspective

Potential but unconfirmed risk factors for coronavirus disease 2019 (COVID-19) in adults and children may include hypertension, cardiovascular disease, and chronic kidney disease, as well as the medications commonly prescribed for these conditions, ACE (angiotensin-converting enzyme) inhibitors, and Ang II (angiotensin II) receptor blockers. Coronavirus binding to ACE2 (angiotensin-converting enzyme 2), a crucial component of the renin-angiotensin-aldosterone system, underlies much of this concern. Children are uniquely impacted by the coronavirus, but the reasons are unclear. This review will highlight the relationship of COVID-19 with hypertension, use of ACE inhibitors and Ang II receptor blockers, and lifetime risk of cardiovascular disease from the pediatric perspective. We briefly summarize the renin-angiotensin-aldosterone system and comprehensively review the literature pertaining to the ACE 2/Ang-(1-7) pathway in children and the clinical evidence for how ACE inhibitors and Ang II receptor blockers affect this important pathway. Given the importance of the ACE 2/Ang-(1-7) pathway and the potential differences between adults and children, it is crucial that children are included in coronavirus-related research, as this may shed light on potential mechanisms for why children are at decreased risk of severe COVID-19.

SARS-CoV-2 Infection and Cardiovascular Disease: COVID-19 Heart

Coronavirus disease (COVID-19) is a serious illness caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The symptoms of the disease range from asymptomatic to mild respiratory symptoms and even potentially life-threatening cardiovascular and pulmonary complications. Cardiac complications include acute myocardial injury, arrhythmias, cardiogenic shock and even sudden death. Furthermore, drug interactions with COVID-19 therapies may place the patient at risk for arrhythmias, cardiomyopathy and sudden death. In this review, we summarise the cardiac manifestations of COVID-19 infection and propose a simplified algorithm for patient management during the COVID-19 pandemic.

COVID-19 and Heart Failure: The Big Challenge

Patients with chronic heart failure (HF) are among the most vulnerable populations in the COVID era. HF patients infected with COVID-19 are at a significant risk of severe illness and death. They usually present with shortness of breath and radiologic signs of an acute decompensation, which can mask the manifestations of COVID-19. Delay in the diagnosis increases the risk of individual poor outcomes and jeopardizes healthcare workers if protective and isolation measures are not established promptly. Furthermore, the COVID-19 pandemic is forcing health-care systems to modify the delivery of care to patients. Outpatient services are being done virtually, and elective procedures postponed. These may have an impact on the quality of life and survival of chronic HF patients. We present two cases of patients with the previous history of HF who developed an acute exacerbation secondary to COVID-19 infection. In this review, we focused on the main challenges physicians face when dealing with COVID-19 in chronic HF patients at the individual and system levels.

Proper Management of People with Obesity during the COVID-19 Pandemic

Since December 2019, countries around the world have been struggling with a novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Case series have reported that people with obesity experience more severe coronavirus disease 2019 (COVID-19). During the COVID-19 pandemic, people have tended to gain weight because of environmental factors imposed by quarantine policies, such as decreased physical activity and increased consumption of unhealthy food. Mechanisms have been postulated to explain the association between COVID-19 and obesity. COVID-19 aggravates inflammation and hypoxia in people with obesity, which can lead to severe illness and the need for intensive care. The immune system is compromised in people with obesity and COVID-19 affects the immune system, which can lead to complications. Interleukin-6 and other cytokines play an important role in the progression of COVID-19. The inflammatory response, critical illness, and underlying risk factors may all predispose to complications of obesity such as diabetes mellitus and cardiovascular diseases. The common medications used to treat people with obesity, such as glucagon-like peptide-1 analogues, statins, and antiplatelets agents, should be continued because these agents have anti-inflammatory properties and play protective roles against cardiovascular and all-cause mortality. It is also recommended that renin–angiotensin system blockers are not stopped during the COVID-19 pandemic because no definitive data about the harm or benefits of these agents have been reported. During the COVID-19 pandemic, social activities have been discouraged and exercise facilities have been closed. Under these restrictions, tailored lifestyle modifications such as home exercise training and cooking of healthy food are encouraged.

Relationship Between ACE2 and Other Components of the Renin-Angiotensin System

PURPOSE OF THE REVIEW

Angiotensin-converting enzyme 2 (ACE2) is a key counter-regulatory component of the renin-angiotensin system. Here, we briefly review the mechanistic and target organ effects related to ACE2 activity, and the importance of ACE2 in SARS-CoV-2 infection.

RECENT FINDINGS

ACE2 converts angiotensin (Ang) II to Ang-(1-7), which directly opposes the vasoconstrictive, proinflammatory, and prothrombotic effects of Ang II. ACE2 also facilitates SARS-CoV-2 viral entry into host cells. Drugs that interact with the renin-angiotensin system may impact ACE2 expression and COVID-19 pathogenesis; however, the magnitude and direction of these effects are unknown at this time. High quality research is needed to improve our understanding of how agents that act on the renin-angiotensin system impact ACE2 and COVID-19-related disease outcomes.

Assisted reproduction and thromboembolic risk in the COVID-19 pandemic

The COVID-19 pandemic has significantly increased mortality in many countries, with the number of infected cases increasing exponentially worldwide. One of the main determining factors of the poor prognosis in these patients is the development of coagulopathy. Moreover, it is well known that assisted reproductive technology procedures confer a risk of thromboembolic complications. This commentary analyses specific aspects coexisting between the thrombotic risk described during virus infection and that reported in the context of assisted reproduction treatments. Based on known pathophysiological aspects of virus infection and of ovarian stimulation, there are common elements that deserve to be taken into account. In the present context, any risk of hyperstimulation should be avoided. Gonadotrophin-releasing hormone agonist triggering should be mandatory in high-responder patients and/or those with COVID-19 infection. In both cases, the cycle should be segmented. A proposal is made for the use of prophylactic low molecular weight heparin not only in those cases in which oocyte retrieval has been performed, but also in those in which cancellation has been decided. In addition, endometrial preparation for frozen-thawed embryo transfers should use the transdermal route in order to minimize the higher thrombotic risk associated with the oral route.

Atrial fibrillation: a risk factor for unfavourable outcome in COVID-19? A case report

Background

Fulminant cardiac involvement in COVID-19 patients has been reported; the underlying suspected mechanisms include myocarditis, arrhythmia, and cardiac tamponade. In parallel, atrial fibrillation is common in the elderly population which is at particularly high risk for COVID-19 morbidity and mortality.

Case summary

A 72-year-old male SARS-CoV2-positive patient was admitted to the intensive care unit due to delirium and acute respiratory failure. Atrial fibrillation known from history was exacerbated, and made complex rate and rhythm control necessary. Progressive heart failure with haemodynamic deterioration and acute kidney injury with the need for continuous renal replacement therapy were further aggravated by pericardial tamponade.

Discussion

Treatment of acute heart failure in COVID-19 patients with a cytokine storm complicated by tachycardic atrial fibrillation should include adequate rate or rhythm control, and potentially immunomodulation.

COVID-19 and heart failure: from infection to inflammation and angiotensin II stimulation. Searching for evidence from a new disease

Patients with cardiovascular disease and, namely, heart failure are more susceptible to coronavirus disease 2019 (COVID‐19) and have a more severe clinical course once infected. Heart failure and myocardial damage, shown by increased troponin plasma levels, occur in at least 10% of patients hospitalized for COVID‐19 with higher percentages, 25% to 35% or more, when patients critically ill or with concomitant cardiac disease are considered. Myocardial injury may be elicited by multiple mechanisms, including those occurring with all severe infections, such as fever, tachycardia, adrenergic stimulation, as well as those caused by an exaggerated inflammatory response, endotheliitis and, in some cases, myocarditis that have been shown in patients with COVID‐19. A key role may be that of the renin–angiotensin–aldosterone system. Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infects human cells binding to angiotensin‐converting enzyme 2 (ACE2), an enzyme responsible for the cleavage of angiotensin II into angiotensin 1–7, which has vasodilating and anti‐inflammatory effects. Virus‐mediated down‐regulation of ACE2 may increase angiotensin II stimulation and contribute to the deleterious hyper‐inflammatory reaction of COVID‐19. On the other hand, ACE2 may be up‐regulated in patients with cardiac disease and treated with ACE inhibitors or angiotensin receptor blockers. ACE2 up‐regulation may increase the susceptibility to COVID‐19 but may be also protective vs. angiotensin II‐mediated vasoconstriction and inflammatory activation. Recent data show the lack of untoward effects of ACE inhibitors or angiotensin receptor blockers for COVID‐19 infection and severity. Prospective trials are needed to ascertain whether these drugs may have protective effects.

Human Gene Sequences in SARS-CoV-2 and Other Viruses

In a previous study, we identified a 117 base severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequence in the human genome with 94.6% identity. The sequence was in chromosome 1p within an intronic region of the netrin G1 (NTNG1) gene. The sequence matched a sequence in the SARS-CoV-2 Orf1b gene in non-structural protein 14 (NSP14), which is an exonuclease and NSP15, an endoribonuclease. In the current study we compared the human genome with other viral genomes to determine some of the characteristics of human sequences found in the latter. Most of the viruses had human sequences, but they were short. Hepatitis A and St Louis encephalitis had human sequences that were longer than the 117 base SARS-Cov-2 sequence, but they were in non-coding regions of the human genome. The SARS-Cov-2 sequence was the only long sequence found in a human gene (NTNG1). The related coronaviruses SARS-Cov had a 41 BP human sequence on chromosome 3 that was not part of a human gene, and MERS had no human sequence. The 117 base SARS-CoV-2 human sequence is relatively close to the viral spike sequence, separated only by NSP16, a 904 base sequence. The mechanism for SARS-CoV-2 infection is the binding of the virus spike protein to the membrane-bound form of angiotensin-converting enzyme 2 (ACE2) and internalization of the complex by the host cell. We have no explanation for the NSP14 and NSP15 SARS-Cov-2 sequences we observed here or how they might relate to infectiousness. Further studies are warranted.

Sex-Specific Modulation of Blood Pressure and the Renin-Angiotensin System by ACE (Angiotensin-Converting Enzyme) 2

We showed ACE (angiotensin-converting enzyme) 2 is higher in the kidney of male compared with female mice. To further investigate this sex difference, we examined the role of ACE2 in Ang-[1-8] (angiotensin [1-8])-induced hypertension and regulation of the renin-angiotensin system in the kidney of WT (wild type) and Ace2 KO (knockout) mice. Mean arterial pressure rose faster in WT male than WT female mice after Ang-[1-8] infusion. This sex difference was attenuated in ACE2 KO mice. Ang-[1-8] infusion reduced glomerular AT1R (angiotensin type 1 receptor) binding in WT female mice by 30%, and deletion of Ace2 abolished this effect. In contrast, Ang-[1-8] infusion increased glomerular AT1R binding in WT male mice by 1.2-fold, and this effect of Ang-[1-8] persisted in Ace2 KO male mice (1.3-fold). ACE2 also had an effect on renal protein expression of the neutral endopeptidase NEP (neprilysin), the enzyme that catabolizes Ang-[1-10] (angiotensin [1-10]), the precursor of Ang-[1-8]. Ang-[1-8] infusion downregulated NEP protein expression by 20% in WT male, whereas there was a slight increase in NEP expression in WT female mice. Deletion of Ace2 resulted in lowered NEP expression after Ang-[1-8] infusion in both sexes. These findings suggest sex-specific ACE2 regulation of the renin-angiotensin system contributes to female protection from Ang-[1-8]-induced hypertension. These findings have ramifications for the current coronavirus disease 2019 (COVID-19) pandemic, especially in hypertension since ACE2 is the SARS-CoV-2 receptor and hypertension is a major risk factor for poor outcomes.

Position Paper for the State-of-the-Art Application of Respiratory Support in Patients with COVID-19

Against the background of the pandemic caused by infection with the SARS-CoV-2 virus, the German Respiratory Society has appointed experts to develop therapy strategies for COVID-19 patients with acute respiratory failure (ARF). Here we present key position statements including observations about the pathophysiology of (ARF). In terms of the pathophysiology of pulmonary infection with SARS-CoV-2, COVID-19 can be divided into 3 phases. Pulmonary damage in advanced COVID-19 often differs from the known changes in acute respiratory distress syndrome (ARDS). Two types (type L and type H) are differentiated, corresponding to early- and late-stage lung damage. This differentiation should be taken into consideration in the respiratory support of ARF. The assessment of the extent of ARF should be based on arterial or capillary blood gas analysis under room air conditions, and it needs to include the calculation of oxygen supply (measured from the variables of oxygen saturation, hemoglobin level, the corrected values of Hüfner's factor, and cardiac output). Aerosols can cause transmission of infectious, virus-laden particles. Open systems or vented systems can increase the release of respirable particles. Procedures in which the invasive ventilation system must be opened and endotracheal intubation carried out are associated with an increased risk of infection. Personal protective equipment (PPE) should have top priority because fear of contagion should not be a primary reason for intubation. Based on the current knowledge, inhalation therapy, nasal high-flow therapy (NHF), continuous positive airway pressure (CPAP), or noninvasive ventilation (NIV) can be performed without an increased risk of infection to staff if PPE is provided. A significant proportion of patients with ARF present with relevant hypoxemia, which often cannot be fully corrected, even with a high inspired oxygen fraction (FiO2) under NHF. In this situation, the oxygen therapy can be escalated to CPAP or NIV when the criteria for endotracheal intubation are not met. In ARF, NIV should be carried out in an intensive care unit or a comparable setting by experienced staff. Under CPAP/NIV, a patient can deteriorate rapidly. For this reason, continuous monitoring and readiness for intubation are to be ensured at all times. If the ARF progresses under CPAP/NIV, intubation should be implemented without delay in patients who do not have a "do not intubate" order.

Intoxication With Endogenous Angiotensin II: A COVID-19 Hypothesis

Severe acute respiratory syndrome coronavirus 2 has spread rapidly around the globe. However, despite its high pathogenicity and transmissibility, the severity of the associated disease, COVID-19, varies widely. While the prognosis is favorable in most patients, critical illness, manifested by respiratory distress, thromboembolism, shock, and multi-organ failure, has been reported in about 5% of cases. Several studies have associated poor COVID-19 outcomes with the exhaustion of natural killer cells and cytotoxic T cells, lymphopenia, and elevated serum levels of D-dimer. In this article, we propose a common pathophysiological denominator for these negative prognostic markers, endogenous, angiotensin II toxicity. We hypothesize that, like in avian influenza, the outlook of COVID-19 is negatively correlated with the intracellular accumulation of angiotensin II promoted by the viral blockade of its degrading enzyme receptors. In this model, upregulated angiotensin II causes premature vascular senescence, leading to dysfunctional coagulation, and immunity. We further hypothesize that angiotensin II blockers and immune checkpoint inhibitors may be salutary for COVID-19 patients with critical illness by reversing both the clotting and immune defects (Graphical Abstract).

Cholesterol in Relation to COVID-19: Should We Care about It?

Current data suggest that infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causing corona virus disease-19 (COVID-19) seems to follow a more severe clinical course in patients with cardiovascular disease (CVD), hypertension, and overweight/obesity. It appears that lipid-lowering pharmacological interventions, in particular statins, might reduce the risk of cardiovascular complications caused by COVID-19 and might potentially have an additional antiviral activity. It has been shown that high cholesterol levels are associated with more lipid rafts, subdomains of the plasma membrane that can harbour angiotensin-converting enzyme 2 (ACE2) receptors for the S-protein of SARS-CoV-2. Evidence of the importance of cholesterol for viral entry into host cells could suggest a role for cholesterol-lowering therapies in reducing viral infectivity. In addition to their lipid-lowering and plaque-stabilisation effects, statins possess pleiotropic effects including anti-inflammatory, immunomodulatory, and antithrombotic activities. Lower rates of mortality and intubation have been reported in studies investigating statin therapy in influenza infection, and statin therapy was shown to increase viral clearance from the blood during chronic hepatitis C infection. Statins may also serve as potential SARS-CoV-2 main protease inhibitors, thereby contributing to the control of viral infection. In this review, we elaborate on the role of cholesterol level in the process of the coronavirus infection and provide a critical appraisal on the potential of statins in reducing the severity, duration, and complications of COVID-19.

Prognostic value of Cardiac Biomarkers in COVID-19 Infection: A Meta-analysis

Background

Multiple Biomarkers have recently been shown to be elevated in COVID-19, a respiratory infection with multi-organ dysfunction; however, information regarding the prognostic value of cardiac biomarkers as it relates to disease severity and cardiac injury are inconsistent.

Research Question

The goal of this meta-analysis was to summarize the evidence regarding the prognostic relevance of cardiac biomarkers from data available in published reports.

Study Design and Methods

PubMed was searched from inception through April 2020 for studies comparing median values of cardiac biomarkers in critically ill versus non-critically ill COVID-19 patients, or patients who died versus those who survived. The weighted mean differences (WMD) and 95% confidence interval (CI) between the groups were calculated for each study and combined using a random effects meta-analysis model. The odds ratio (OR) for mortality based on cardiac injury was combined from studies reporting it.

Results

Troponin levels were significantly higher in COVID-19 patients who died or were critically ill versus those who were alive or not critically ill (WMD 0.58, 95% CI 0.42–0.71, p<0.001). Cardiac injury was independently associated with significantly increased odds of mortality (OR 6.641, 95% CI 1.26 – 35.1, p=0.03). No difference in BNP was seen between the two groups. A significant difference in levels of D-dimer was seen in those who died or were critically ill. CK levels were only significantly higher in those who died versus those who were alive (WMD 0.47 95% CI 0.09–0.84, p=0.014).

Interpretation

Cardiac biomarkers add prognostic value to the determination of the severity of COVID-19 and can predict mortality.

Insights into SARS-CoV-2 genome, structure, evolution, pathogenesis and therapies: Structural genomics approach

The sudden emergence of severe respiratory disease, caused by a novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has recently become a public health emergency. Genome sequence analysis of SARS-CoV-2 revealed its close resemblance to the earlier reported SARS-CoV and Middle East respiratory syndrome coronavirus (MERS-CoV). However, initial testing of the drugs used against SARS-CoV and MERS-CoV has been ineffective in controlling SARS-CoV-2. The present study highlights the genomic, proteomic, pathogenesis, and therapeutic strategies in SARS-CoV-2 infection. We have carried out sequence analysis of potential drug target proteins in SARS-CoV-2 and, compared them with SARS-CoV and MERS viruses. Analysis of mutations in the coding and non-coding regions, genetic diversity, and pathogenicity of SARS-CoV-2 has also been done. A detailed structural analysis of drug target proteins has been performed to gain insights into the mechanism of pathogenesis, structure-function relationships, and the development of structure-guided therapeutic approaches. The cytokine profiling and inflammatory signalling are different in the case of SARS-CoV-2 infection. We also highlighted possible therapies and their mechanism of action followed by clinical manifestation. Our analysis suggests a minimal variation in the genome sequence of SARS-CoV-2, may be responsible for a drastic change in the structures of target proteins, which makes available drugs ineffective.

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The recent exposure to SARS-CoV-2 has affected entire world, resulted >0.4 million deaths.

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Potential drug targets of SARS-CoV-2 are highly conserved.

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A slight structural difference makes available drugs ineffective against SARS-CoV-2.

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Cytokine storm during SARS-CoV-2 infection may be targeted to handle COVID-19 patients.

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Many FDA approved drugs are showing positive effects in clinical trials but further validation in large subject groups is required.

SARS-CoV-2 pandemic and research gaps: Understanding SARS-CoV-2 interaction with the ACE2 receptor and implications for therapy

The COVID-19 pandemic is an emerging threat to global public health. While our current understanding of COVID-19 pathogenesis is limited, a better understanding will help us develop efficacious treatment and prevention strategies for COVID-19. One potential therapeutic target is angiotensin converting enzyme 2 (ACE2). ACE2 primarily catalyzes the conversion of angiotensin I (Ang I) to a nonapeptide angiotensin or the conversion of angiotensin II (Ang II) to angiotensin 1-7 (Ang 1-7) and has direct effects on cardiac function and multiple organs via counter-regulation of the renin-angiotensin system (RAS). Significant to COVID-19, ACE2 is postulated to serve as a major entry receptor for SARS-CoV-2 in human cells, as it does for SARS-CoV. Many infected individuals develop COVID-19 with fever, cough, and shortness of breath that can progress to pneumonia. Disease progression promotes the activation of immune cells, platelets, and coagulation pathways that can lead to multiple organ failure and death. ACE2 is expressed by epithelial cells of the lungs at high level, a major target of the disease, as seen in post-mortem lung tissue of patients who died with COVID-19, which reveals diffuse alveolar damage with cellular fibromyxoid exudates bilaterally. Comparatively, ACE2 is expressed at low level by vascular endothelial cells of the heart and kidney but may also be targeted by the virus in severe COVID-19 cases. Interestingly, SARS-CoV-2 infection downregulates ACE2 expression, which may also play a critical pathogenic role in COVID-19. Importantly, targeting ACE2/Ang 1-7 axis and blocking ACE2 interaction with the S protein of SARS-CoV-2 to curtail SARS-CoV-2 infection are becoming very attractive therapeutics potential for treatment and prevention of COVID-19. Here, we will discuss the following subtopics: 1) ACE2 as a receptor of SARS-CoV-2; 2) clinical and pathological features of COVID-19; 3) role of ACE2 in the infection and pathogenesis of SARS; 4) potential pathogenic role of ACE2 in COVID-19; 5) animal models for pathological studies and therapeutics; and 6) therapeutics development for COVID-19.

Review of evidence on using ACEi and ARBs in patients with hypertension and COVID-19

COVID-19 has recently become a major pandemic with associated socioeconomic dimensions. Mortality statistics suggest that COVID-19 is more lethal in aged patients with comorbid conditions including hypertension. There is ongoing debate about whether the use of angiotensin converting enzyme (ACE) inhibitors (ACEi) and angiotensin receptor blockers (ARBs) are useful or hazardous in patients with COVID-19, with both narratives supported by researchers with different hypotheses. The researchers supporting the use of these medications believe ACE2 functional blockers may block cellular entry of the SARS-CoV-2 virus and thus improve patient outcomes. The counter viewpoint argues that continuous use of these drugs results in hyperexpression of ACE2 receptors on respiratory epithelium allowing easier SARS-CoV-2 intracellular entry, resulting in enhanced viral replication and tissue damage. This short review discusses the available research on the subject with the objective to consolidate data to allow formulation of recommendations on their use or otherwise. Moreover, the authors also suggest areas for future research on the subject.

COVID-19: from epidemiology to treatment

The COVID-19 pandemic has greatly impacted the daily clinical practice of cardiologists and cardiovascular surgeons. Preparedness of health workers and health services is crucial to tackle the enormous challenge posed by SARS-CoV-2 in wards, operating theatres, intensive care units, and interventionist laboratories. This Clinical Review provides an overview of COVID-19 and focuses on relevant aspects on prevention and management for specialists within the cardiovascular field.

COVID-19: Specific and Non-Specific Clinical Manifestations and Symptoms: The Current State of Knowledge

Coronavirus disease 2019 (COVID-19), due to the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has become an epidemiological threat and a worldwide concern. SARS-CoV-2 has spread to 210 countries worldwide and more than 6,500,000 confirmed cases and 384,643 deaths have been reported, while the number of both confirmed and fatal cases is continually increasing. COVID-19 is a viral disease that can affect every age group-from infants to the elderly-resulting in a wide spectrum of various clinical manifestations. COVID-19 might present different degrees of severity-from mild or even asymptomatic carriers, even to fatal cases. The most common complications include pneumonia and acute respiratory distress syndrome. Fever, dry cough, muscle weakness, and chest pain are the most prevalent and typical symptoms of COVID-19. However, patients might also present atypical symptoms that can occur alone, which might indicate the possible SARS-CoV-2 infection. The aim of this paper is to review and summarize all of the findings regarding clinical manifestations of COVID-19 patients, which include respiratory, neurological, olfactory and gustatory, gastrointestinal, ophthalmic, dermatological, cardiac, and rheumatologic manifestations, as well as specific symptoms in pediatric patients.

COVID-19 pandemic and troponin: indirect myocardial injury, myocardial inflammation or myocarditis?

The initial mechanism for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection is the binding of the virus to the membrane-bound form of ACE2, which is mainly expressed in the lung. Since the heart and the vessels also express ACE2, they both could become targets of the virus. However, at present the extent and importance of this potential involvement are unknown. Cardiac troponin levels are significantly higher in patients with more severe infections, patients admitted to intensive care units or in those who have died. In the setting of COVID-19, myocardial injury, defined by an increased troponin level, occurs especially due to non-ischaemic myocardial processes, including severe respiratory infection with hypoxia, sepsis, systemic inflammation, pulmonary thrombosis and embolism, cardiac adrenergic hyperstimulation during cytokine storm syndrome, and myocarditis. At present, there are limited reports on definite diagnosis of myocarditis caused by SARS-CoV-2 in humans and limited demonstration of the virus in the myocardium. In conclusion, although the heart and the vessels are potential targets in COVID-19, there is currently limited evidence on the direct infection of the myocardium by SARS-CoV-2. Additional pathological studies and autopsy series will be very helpful to clarify the potentiality of COVID-19 to directly infect the myocardium and cause myocarditis.

Protective role of ACE2 and its downregulation in SARS-CoV-2 infection leading to Macrophage Activation Syndrome: Therapeutic implications

In light of the outbreak of the 2019 novel coronavirus disease (COVID-19), the international scientific community has joined forces to develop effective treatment strategies. The Angiotensin-Converting Enzyme (ACE) 2, is an essential receptor for cell fusion and engulfs the SARS coronavirus infections. ACE2 plays an important physiological role, practically in all the organs and systems. Also, ACE2 exerts protective functions in various models of pathologies with acute and chronic inflammation. While ACE2 downregulation by SARS-CoV-2 spike protein leads to an overactivation of Angiotensin (Ang) II/AT1R axis and the deleterious effects of Ang II may explain the multiorgan dysfunction seen in patients. Specifically, the role of Ang II leading to the appearance of Macrophage Activation Syndrome (MAS) and the cytokine storm in COVID-19 is discussed below. In this review, we summarized the latest research progress in the strategies of treatments that mainly focus on reducing the Ang II-induced deleterious effects rather than attenuating the virus replication.

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Protective role of ACE2 in the organs and system

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Downregulation of ACE2 expression by SARS-CoV-2 leads to Ang II-induced organ damage.

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The appearance of MAS in COVID-19 patient

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Suggested treatment to diminish the deleterious effect of Ang II or appearance of MAS

Coronavirus Infections and Type 2 Diabetes-Shared Pathways with Therapeutic Implications

Individuals with diabetes are at increased risk for bacterial, mycotic, parasitic, and viral infections. The severe acute respiratory syndrome (SARS)-CoV-2 (also referred to as COVID-19) coronavirus pandemic highlights the importance of understanding shared disease pathophysiology potentially informing therapeutic choices in individuals with type 2 diabetes (T2D). Two coronavirus receptor proteins, angiotensin-converting enzyme 2 (ACE2) and dipeptidyl peptidase-4 (DPP4) are also established transducers of metabolic signals and pathways regulating inflammation, renal and cardiovascular physiology, and glucose homeostasis. Moreover, glucose-lowering agents such as the DPP4 inhibitors, widely used in subjects with T2D, are known to modify the biological activities of multiple immunomodulatory substrates. Here, we review the basic and clinical science spanning the intersections of diabetes, coronavirus infections, ACE2, and DPP4 biology, highlighting clinical relevance and evolving areas of uncertainty underlying the pathophysiology and treatment of T2D in the context of coronavirus infection.

Impact of Corona Virus Disease-19 (COVID-19) pandemic on gastrointestinal disorders

Worldwide, several hospitals in different regions and countries have been affected with Corona Virus Disease-19 (COVID-19). All medical specialties including gastroenterology are impacted by COVID-19. Here, we review the bidirectional comorbidity of chronic gastrointestinal (GI) disorders and COVID-19, including the incidence and outcome of COVID-19 in individuals with various GI disorders and the impact of COVID-19 on the course and outcome of the underlying (or comorbid) GI disorders. Currently, there is no evidence that COVID-19 is more (or less) frequent in comorbid GI disorders. It is also reassuring that the outcome of COVID-19 is unaffected by the underlying GI disorder or its treatment, though potential concerns remain in regard to the use of immunomodulatory treatments in inflammatory bowel disease (IBD) and liver transplant recipients. Despite these concerns, there is now agreement among experts that ongoing immunomodulatory treatments may not be interrupted in individuals with IBD during the COVID-19 pandemic. Caution, however, may be exercised with the use of corticosteroids in the management of IBD. In addition, COVID-19 does not appear to impact the manifestations, course, outcome, and treatment of comorbid GI disorders, e.g. IBD. Decompensation of liver cirrhosis is, however, possible during COVID-19 episodes. A direct concern, however, might relate to the potential transmission of the virus through fecal microbiota transplants.

[Position Paper for the State of the Art Application of Respiratory Support in Patients with COVID-19 - German Respiratory Society]

Against the background of the pandemic caused by infection with the SARS-CoV-2, the German Society for Pneumology and Respiratory Medicine (DGP e.V.), in cooperation with other associations, has designated a team of experts in order to answer the currently pressing questions about therapy strategies in dealing with COVID-19 patients suffering from acute respiratory insufficiency (ARI).The position paper is based on the current knowledge that is evolving daily. Many of the published and cited studies require further review, also because many of them did not undergo standard review processes.Therefore, this position paper is also subject to a continuous review process and will be further developed in cooperation with the other professional societies.This position paper is structured into the following five topics:1. Pathophysiology of acute respiratory insufficiency in patients without immunity infected with SARS-CoV-22. Temporal course and prognosis of acute respiratory insufficiency during the course of the disease3. Oxygen insufflation, high-flow oxygen, non-invasive ventilation and invasive ventilation with special consideration of infectious aerosol formation4. Non-invasive ventilation in ARI5. Supply continuum for the treatment of ARIKey points have been highlighted as core statements and significant observations. Regarding the pathophysiological aspects of acute respiratory insufficiency (ARI), the pulmonary infection with SARS-CoV-2 COVID-19 runs through three phases: early infection, pulmonary manifestation and severe hyperinflammatory phase.There are differences between advanced COVID-19-induced lung damage and those changes seen in Acute Respiratory Distress Syndromes (ARDS) as defined by the Berlin criteria. In a pathophysiologically plausible - but currently not yet histopathologically substantiated - model, two types (L-type and H-type) are distinguished, which correspond to an early and late phase. This distinction can be taken into consideration in the differential instrumentation in the therapy of ARI.The assessment of the extent of ARI should be carried out by an arterial or capillary blood gas analysis under room air conditions and must include the calculation of the oxygen supply (measured from the variables of oxygen saturation, the Hb value, the corrected values of the Hüfner number and the cardiac output). In principle, aerosols can cause transmission of infectious viral particles. Open systems or leakage systems (so-called vented masks) can prevent the release of respirable particles. Procedures in which the invasive ventilation system must be opened, and endotracheal intubation must be carried out are associated with an increased risk of infection.The protection of personnel with personal protective equipment should have very high priority because fear of contagion must not be a primary reason for intubation. If the specifications for protective equipment (eye protection, FFP2 or FFP-3 mask, gown) are adhered to, inhalation therapy, nasal high-flow (NHF) therapy, CPAP therapy or NIV can be carried out according to the current state of knowledge without increased risk of infection to the staff. A significant proportion of patients with respiratory failure presents with relevant hypoxemia, often also caused by a high inspiratory oxygen fraction (FiO2) including NHF, and this hypoxemia cannot be not completely corrected. In this situation, CPAP/NIV therapy can be administered under use of a mouth and nose mask or a respiratory helmet as therapy escalation, as long as the criteria for endotracheal intubation are not fulfilled.In acute hypoxemic respiratory insufficiency, NIV should be performed in an intensive care unit or in a comparable unit by personnel with appropriate expertise. Under CPAP/NIV, a patient can deteriorate rapidly. For this reason, continuous monitoring with readiness to carry out intubation must be ensured at all times. If CPAP/NIV leads to further progression of ARI, intubation and subsequent invasive ventilation should be carried out without delay if no DNI order is in place.In the case of patients in whom invasive ventilation, after exhausting all guideline-based measures, is not sufficient, extracorporeal membrane oxygenation procedure (ECMO) should be considered to ensure sufficient oxygen supply and to remove CO2.

Biological sex impacts COVID-19 outcomes

The current novel coronavirus disease 2019 (COVID-19) pandemic is revealing profound differences between men and women in disease outcomes worldwide. In the United States, there has been inconsistent reporting and analyses of male-female differences in COVID-19 cases, hospitalizations, and deaths. We seek to raise awareness about the male-biased severe outcomes from COVID-19, highlighting the mechanistic differences including in the expression and activity of angiotensin-converting enzyme 2 (ACE2) as well as in antiviral immunity. We also highlight how sex differences in comorbidities, which can be associated with both age and race, impact male-biased outcomes from COVID-19.

What every orthopaedic surgeon should know about COVID-19: A review of the current literature

The coronavirus (COVID-19) pandemic has severely affected the medical community and stopped the world in its tracks. This review aims to provide the basic information necessary for us, orthopaedic surgeons to prepare ourselves to face this pandemic together. Herein, we cover the background of COVID-19, presentation, investigations, transmission, infection control and touch upon emerging treatments. It is of paramount importance that we should stay vigilant for our patients, our families and ourselves. Adequate infection control measures are necessary during day-to-day clinical work.

Cardiovascular disease management during the coronavirus disease 2019 pandemic

Based on clinical presentation, pathophysiology, high infectivity, high cardiovascular involvement, and therapeutic agents with cardiovascular toxicity of coronavirus disease 2019 (COVID-19), regular cardiovascular treatment is being changing greatly. Despite angiotensin-converting enzyme 2 serving as the portal for infection, the continuation of clinically indicated renin-angiotensin-aldosterone blockers is recommended according to the present evidence. Fibrinolytic therapy can be considered a reasonable option for the relatively stable ST segment elevation myocardial infarction (STEMI) patient with suspected or known COVID-19. However, primary percutaneous coronary intervention is still the standard of care in patients with definite STEMI if personal protective equipment is available and cardiac catheterization laboratory has a good infection control. In patients with elevated cardiac enzymes, it is very important to differentiate patients with Type 2 myocardial infarction or myocarditis from those with true acute coronary syndromes because invasive percutaneous intervention management in the former may be unnecessary, especially if they are hemodynamically stable. Finally, patients with baseline QT prolongation or those taking QT prolonging drugs must be cautious when treating with lopinavir/ritonavir and hydroxychloroquine for COVID-19.

Alternative splicing of ACE2 possibly generates variants that may limit the entry of SARS-CoV-2: a potential therapeutic approach using SSOs

Angiotensin-converting enzyme 2 (ACE2) plays an essential role in maintaining the balance of the renin-angiotensin system and also serves as a receptor for the SARS-CoV-2, SARS-CoV, and HCoV-NL63. Following the recent outbreak of SARS-CoV-2 infection, there has been an urgent need to develop therapeutic interventions. ACE2 is a potential target for many treatment approaches for the SARS-CoV-2. With the help of bioinformatics, we have predicted several novel exons of the human ACE2 gene. The inclusion of novel exons located in the 5'UTR/intronic region in the mature transcript may remove the critical ACE2 residues responsible for the interaction with the receptor-binding domain (RBD) of SARS-CoV-2, thus preventing their binding and entry into the cell. Additionally, inclusion of a novel predicted exons located in the 3'UTR by alternative splicing may remove the C-terminal transmembrane domain of ACE2 and generate soluble ACE2 isoforms. Splice-switching antisense oligonucleotides (SSOs) have been employed effectively as a therapeutic strategy in several disease conditions. Alternative splicing of the ACE2 gene could similarly be modulated using SSOs to exclude critical domains required for the entry of SARS-CoV-2. Strategies can also be designed to deliver these SSOs directly to the lungs in order to minimize the damage caused by SARS-CoV-2 pathogenesis.

The Biology of Lactoferrin, an Iron-Binding Protein That Can Help Defend Against Viruses and Bacteria

Lactoferrin is a nutrient classically found in mammalian milk. It binds iron and is transferred via a variety of receptors into and between cells, serum, bile, and cerebrospinal fluid. It has important immunological properties, and is both antibacterial and antiviral. In particular, there is evidence that it can bind to at least some of the receptors used by coronaviruses and thereby block their entry. Of importance are Heparan Sulfate Proteoglycans (HSPGs) and the host receptor angiotensin-converting enzyme 2 (ACE2), as based on other activities lactoferrin might prevent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from attaching to the host cells. Lactoferrin (and more specifically enteric-coated LF because of increased bioavailability) may consequently be of preventive and therapeutic value during the present COVID-19 pandemic.

Persistent SARS-CoV-2 infection and the risk for cancer

The current SARS-CoV-2 has put significant strain on healthcare services worldwide due to acute COVID-19. However, the potential long-term effects of this infection haven’t been extensively discussed.

We hypothesize that SARS-CoV-2 may be able to cause persistent infection in some individuals, and should this be the case, that in a few years we may see a rise in cancer incidence due to carcinogenic effects of this coronavirus.

Non-retroviral RNA viruses such as Coronaviridae have been shown to cause persistent infection in hosts. Empirical evidence of viral genomic material shedding weeks after apparent clinical and laboratorial resolution of COVID-19 may be an indirect proof for persistent viral infection. Furthermore, tropism towards certain immune-privileged territories may facilitate immune evasion by this virus.

Structural homology with SARS-CoV-1 indicates that SARS-CoV-2 may be able to directly impair pRb and p53, which are key gatekeepers with tumor suppressor functions. Additionally, COVID-19 features preeminent inflammatory response with marked oxidative stress, which acts as both as initiator and promotor of carcinogenesis.

Should there be a carcinogenic risk associated with SARS-CoV-2, the implications for public health are plenty, as infected patients should be closely watched during long periods of follow-up.

Additional investigation to establish or exclude the possibility for persistent infection is paramount to identify and prevent possible complications in the future.

Molecular Characterization and Amino Acid Homology of Nucleocapsid (N) Protein in SARS-CoV-1, SARS-CoV-2, MERS-CoV, and Bat Coronavirus

Coronavirus disease – 2019 (COVID-19) pandemic, due to severe acute respiratory syndrome–coronavirus-2 (SARS-CoV-2), is posing a severe bio threat to the entire world. Nucleocapsids of SARS-CoV-2 and the related viruses were studied for gene and amino acid sequence homologies. In this study, we established similarities and differences in nucleocapsids in SARS-CoV-2, severe acute respiratory syndrome – coronavirus-1 (SARS-CoV-1), bat coronavirus (bat-CoV) and Middle East respiratory syndrome – coronavirus (MERS-CoV). We conducted a detailed analysis of the nucleocapsid protein amino acid and gene sequence encoding it, found in various coronavirus strains. After thoroughly screening the different nucleocapsids, we observed a close molecular homology between SARS-CoV-1 and SARS-CoV-2. More than 95% sequence similarity was observed between the two SARS-CoV strains. Bat-CoV and SARS-CoV-2 showed 92% sequence similarity. MERS-CoV and SARS-CoV-2 nucleocapsid analysis indicated only 65% identity. Molecular characterization of nucleocapsids from various coronaviruses revealed that SARS-CoV 2 is more related to SARS-CoV 1 and bat-CoV. SARS-CoV 2 exhibited less resemblance with MERS-CoV. SARS-CoV 2 showed less similarity to MERS-CoV. Thus, either SARS-CoV-1 or bat-CoV may be the source of SARS-CoV-2 evolution. Moreover, the existing differences in nucleocapsid molecular structures in SARS-CoV-2 make this virus more virulent and highly infectious, which means that the non-identical SARS-CoV-2 genes (which are absent in SARS-CoV-1 and bat-CoV) are responsible for COVID-19 severity. We observed that SARS-CoV-2 nucleocapsid from different locations varied in amino acid sequences. This revealed that there are many SARS-CoV-2 subtypes/subsets currently circulating globally. This study will help to develop antiviral vaccine and drugs, study viral replication and immunopathogenesis, and synthesize monoclonal antibodies that can be used for precise COVID-19 diagnosis, without false-positive/false-negative results.

A Guide to the Short, Long and Circular RNAs in Hypertension and Cardiovascular Disease

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in adults in developed countries. CVD encompasses many diseased states, including hypertension, coronary artery disease and atherosclerosis. Studies in animal models and human studies have elucidated the contribution of many genetic factors, including non-coding RNAs. Non-coding RNAs are RNAs not translated into protein, involved in gene expression regulation post-transcriptionally and implicated in CVD. Of these, circular RNAs (circRNAs) and microRNAs are relevant. CircRNAs are created by the back-splicing of pre-messenger RNA and have been underexplored as contributors to CVD. These circRNAs may also act as biomarkers of human disease, as they can be extracted from whole blood, plasma, saliva and seminal fluid. CircRNAs have recently been implicated in various disease processes, including hypertension and other cardiovascular disease. This review article will explore the promising and emerging roles of circRNAs as potential biomarkers and therapeutic targets in CVD, in particular hypertension.

Hypertension, Thrombosis, Kidney Failure, and Diabetes: Is COVID-19 an Endothelial Disease? A Comprehensive Evaluation of Clinical and Basic Evidence

The symptoms most commonly reported by patients affected by coronavirus disease (COVID-19) include cough, fever, and shortness of breath. However, other major events usually observed in COVID-19 patients (e.g., high blood pressure, arterial and venous thromboembolism, kidney disease, neurologic disorders, and diabetes mellitus) indicate that the virus is targeting the endothelium, one of the largest organs in the human body. Herein, we report a systematic and comprehensive evaluation of both clinical and preclinical evidence supporting the hypothesis that the endothelium is a key target organ in COVID-19, providing a mechanistic rationale behind its systemic manifestations.

Brief recommendations on the management of adult patients with familial hypercholesterolemia during the COVID-19 pandemic

Individuals with Familial Hypercholesterolaemia (FH) are at very high risk of cardiovascular disease, which is associated with poor outcomes from coronavirus infections. COVID-19 puts strain on healthcare systems and may impair access to routine FH services. On behalf of the International Lipid Expert Panel (ILEP) and the European FH Patient Network (FH Europe), we present brief recommendations on the management of adult patients with FH during the COVID-19 pandemic. We discuss the implications of COVID-19 infections for FH patients, the importance of continuing lipid-lowering therapy where possible, issues relating to safety monitoring and service delivery. We summarise the evidence for additional benefits of statins and other lipid-lowering drugs during viral infections. The recommendations do not override in any way the individual responsibility of physicians to make appropriate and accurate decisions taking into account the condition of a given patient and the doses, rules, and regulations applicable to drugs and devices at the time of their prescription/use.