Characterization of COVID-19-associated cardiac injury: evidence for a multifactorial disease in an autopsy cohort

NETosis: A key player in autoimmunity, COVID-19, and long COVID

NETosis, the process through which neutrophils release neutrophil extracellular traps (NETs), has emerged as a crucial mechanism in host defense and the pathogenesis of autoimmune responses. During the SARS-CoV-2 pandemic, this process received significant attention due to the central role of neutrophil recruitment and activation in infection control. However, elevated neutrophil levels and dysregulated NET formation have been linked to coagulopathy and endothelial damage, correlating with disease severity and poor prognosis in COVID-19. Moreover, it is known that SARS-CoV-2 can induce persistent low-grade systemic inflammation, known as long COVID, although the underlying causes remain unclear. It has been increasingly acknowledged that excessive NETosis and NET generation contribute to further pathophysiological abnormalities following SARS-CoV-2 infection. This review provides an updated overview of the role of NETosis in autoimmune diseases, but also the relationship between COVID-19 and long COVID with autoimmunity (e.g., latent and overt autoimmunity, molecular mimicry, epitope spreading) and NETosis (e.g., immune responses, NET markers). Finally, we discuss potential therapeutic strategies targeting dysregulated NETosis to mitigate the severe complications of COVID-19 and long COVID.

Mitochondrial injury and complement dysregulation are drivers of pathological inflammation in viral myocarditis

Enteroviruses cause nearly 1 billion global infections annually and are associated with a diverse array of human illnesses. Among these, myocarditis and the resulting chronic inflammation have been recognized as major contributing factors to virus-induced heart failure. Despite our growing understanding, very limited therapeutic strategies have been developed to address the pathological consequences of virus-induced chronic innate immune activation. Coxsackievirus B3 (CVB3) was used as a model cardiotropic enterovirus. We leveraged in vitro cell-based studies to investigate cardiomyocyte and macrophage interaction during CVB3 infection, as well as animal studies and unique human cardio specimens to evaluate mechanisms of viral heart injury. We present evidence that viral myocarditis is in part exacerbated by pathological activation of the complement pathway in cells, mice, and human cardiac tissues. We demonstrate unique cell type-specific responses to viral infection that are exacerbated by mitochondrial injury in cardiomyocytes and NFκB-dependent pro-inflammatory response in macrophages. Macrophages are robustly activated by damage-associated mitochondrial components, including mitochondrial proteins and lipid extracts. Mechanistically, we identify complement protective factors CD59/protectin and CD55/DAF as novel targets of viral proteinase that acts to release the brakes on complement-mediated autoinjury. Collectively, our study highlights a novel mechanism that can act as a potential contributor to CVB3 pathogenesis through mitochondrial injury-mediated autoimmunity.

IMPORTANCE

This study sheds light on how enteroviruses, specifically coxsackievirus B3, may contribute to heart failure by triggering harmful immune responses in the heart. We discovered that viral infections in heart cells cause mitochondrial damage, which in turn activates a destructive immune response involving the complement system. This immune activation is one of the significant contributors that lead to further injury of heart tissues, worsening the damage caused by the virus. Additionally, we identified key protective molecules that are targeted and disrupted by the virus, allowing the immune system to attack the heart even more aggressively. Understanding these mechanisms may provide additional insights into how viral infections can lead to chronic heart conditions and suggests potential therapeutic targets to prevent or reduce heart damage in patients affected by viral myocarditis.

Risk impact of SARS-CoV-2 coronavirus and spike protein on cardiac tissue: a comprehensive review

The global COVID-19 pandemic, caused by SARS-CoV-2, has led to significant morbidity and mortality, with a profound impact on cardiovascular health. This review investigates the mechanisms of SARS-CoV-2's interaction with cardiac tissue, particularly emphasizing the role of the Spike protein and ACE2 receptor in facilitating viral entry and subsequent cardiac complications. We dissect the structural features of the virus, its interactions with host cell receptors, and the resulting pathophysiological changes in the heart. Highlighting SARS-CoV-2's broad organ tropism, especially its effects on cardiomyocytes via ACE2 and TMPRSS2, the review addresses how these interactions exacerbate cardiovascular issues in patients with pre-existing conditions such as diabetes and hypertension. Additionally, we assess both direct and indirect mechanisms of virus-induced cardiac damage, including myocarditis, arrhythmias, and long-term complications such as 'long COVID'. This review underscores the complexity of SARS-CoV-2's impact on the heart, emphasizing the need for ongoing research to fully understand its long-term effects on cardiovascular health. Key words: COVID-19, Heart, ACE2, Spike protein, Cardiomyocytes, Myocarditis, Long COVID.

Unraveling the relevance of SARS-Cov-2 infection and ferroptosis within the heart of COVID-19 patients

Background

The coronavirus disease 2019 (COVID-19) was caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which led to a huge mortality rate and imposed significant costs on the health system, causing severe damage to the cells of different organs such as the heart. However, the exact details and mechanisms behind this damage are not clarified. Therefore, we aimed to identify the cell and molecular mechanism behind the heart damage caused by SARS-Cov-2 infection.

Methods

RNA-seq data for COVID-19 patients' hearts was analyzed to obtain differentially expressed genes (DEGs) and differentially expressed ferroptosis-related genes (DEFRGs). Then, DEFRGs were used for analyzing GO and KEGG enrichment, and perdition of metabolites and drugs. we also constructed a PPI network and identified hub genes and functional modules for the DEFRGs. Subsequently, the hub genes were validated using two independent RNA-seq datasets. Finally, the miRNA-gene interaction networks were predicted in addition to a miRNA-TF co-regulatory network, and important miRNAs and transcription factors (TFs) were highlighted.

Findings

We found ferroptosis transcriptomic alterations within the hearts of COVID-19 patients. The enrichment analyses suggested the involvement of DEFRGs in the citrate cycle pathway, ferroptosis, carbon metabolism, amino acid biosynthesis, and response to oxidative stress. IL6, CDH1, AR, EGR1, SIRT3, GPT2, VDR, PCK2, VDR, and MUC1 were identified as the ferroptosis-related hub genes. The important miRNAs and TFs were miR-124-3P, miR-26b-5p, miR-183-5p, miR-34a-5p and miR-155-5p; EGR1, AR, IL6, HNF4A, SRC, EZH2, PPARA, and VDR.

Conclusion

These results provide a useful context and a cellular snapshot of how ferroptosis affects cardiomyocytes (CMs) in COVID-19 patients' hearts. Besides, suppressing ferroptosis seems to be a beneficial therapeutic approach to mitigate heart damage in COVID-19.

Cardiac SARS-CoV-2 Infection, Involvement of Cytokines in Postmortem Immunohistochemical Study

In the context of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, significant attention was given to pulmonary manifestations. However, cardiac involvement is increasingly recognized as a critical factor influencing the prognosis, leading to myocardial damage, heart failure, acute coronary syndromes, potentially lethal arrhythmic events, and sudden cardiac death. Despite these findings, there is a lack of studies detailing the necroscopic, macroscopic, and microscopic cardiac changes associated with SARS-CoV-2. This study aimed to investigate the presence of SARS-CoV-2 viral proteins in cardiac tissue using immunohistochemical techniques to assess viral tropism. The analysis of cardiac tissue samples from deceased subjects, in different stages of conservation, confirmed to be positive for SARS-CoV-2 via reverse transcriptase-polymerase chain reaction (RT-PCR), showed immunopositivity for the SARS-CoV-2-NP viral antigen in 33% of cases. Notably, the presence of leukocyte infiltrates sufficient for diagnosing lymphocytic myocarditis was not observed. The central proinflammatory cytokines involved in the pathogenetic mechanism of coronavirus disease 19 (COVID-19) were researched using the immunohistochemical method. A significant increase in cytokine expression was detected, indicating myocardial involvement and dysfunction during SARS-CoV-2 infection. These findings suggest that the immunohistochemical detection of SARS-CoV-2 viral antigens and inflammatory cytokine expression in cardiac tissue could be crucial for a proper forensic assessment of the cause of death, even in sudden cardiac death.

COVID-19 and cardiovascular disease in patients with chronic kidney disease

Millions of people worldwide have chronic kidney disease (CKD). Affected patients are at high risk for cardiovascular (CV) disease for several reasons. Among various comorbidities, CKD is associated with the more severe forms of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. This is particularly true for patients receiving dialysis or for kidney recipients. From the start of the SARS-CoV-2 pandemic, several CV complications have been observed in affected subjects, spanning acute inflammatory manifestations, CV events, thrombotic episodes and arrythmias. Several pathogenetic mechanisms have been hypothesized, including direct cytopathic viral effects on the myocardium, endothelial damage and hypercoagulability. This spectrum of disease can occur during the acute phase of the infection, but also months after recovery. This review is focussed on the CV complications of coronavirus disease 2019 (COVID-19) with particular interest in their implications for the CKD population.

Myocardial injury and related mortality in hospitalized patients with COVID-19 during the Omicron pandemic: new perspectives and insights

Myocardial injury is one of the most common comorbidity in SARS-CoV-2 infected patients, and has poor prognosis. However, the incidence of myocardial injury in patients with SARS-CoV-2 infection has not been sufficiently investigated during the Omicron wave. We conducted a retrospective study of 2690 patients with confirmed SARS-CoV-2 Omicron infection from Tongji Hospital. The results indicated that the myocardial injury accounted for 30.8% of the total patients with SARS-CoV-2 infection and was associated with higher in-hospital mortality than those without injury before and after propensity score matching (PSM) [adjusted hazard ratio (HR), 10.61; 95% confidence interval (CI), 7.76-14.51; P ​< ​0.001; adjusted HR, 2.70; 95% CI, 1.86-3.93; P ​< ​0.001; respectively]. Further, the levels of cytokines (IL-1β, IL-6, IL-10, and TNF-α) in patients with myocardial injury were higher than those without injury, and the higher levels of cytokines in the myocardial injury group were associated with increased mortality. Administration of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers (ACEI/ARB) could significantly reduce the mortality in patients with myocardial injury (adjusted HR, 0.52; 95% CI, 0.38-0.71; P ​< ​0.001). Additionally, the level of angiotensin II increased in patients with SARS-CoV-2 infection was even higher in myocardial injury group compared to those without injury. Collectively, the study summarized the clinical characteristic and outcome of SARS-CoV-2 infected patients with myocardial injury during the Omicron wave in China, and validated the protective role of ACEI/ARB in improving the survival of those with myocardial injury.

A comprehensive analysis of all-cause and cause-specific excess deaths in 30 countries during 2020

The impact of COVID-19 on mortality from specific causes of death remains poorly understood. This study analysed cause-of-death data provided by the World Health Organization from 2011 to 2019 to estimate excess deaths in 2020 in 30 countries. Over-dispersed Poisson regression models were used to estimate the number of deaths that would have been expected if the pandemic had not occurred, separately for men and women. The models included year and age categories to account for temporal trends and changes in size and age structure of the populations. Excess deaths were calculated by subtracting observed deaths from expected ones. Our analysis revealed significant excess deaths from ischemic heart diseases (IHD) (in 10 countries), cerebrovascular diseases (CVD) (in 10 countries), and diabetes (in 19 countries). The majority of countries experienced excess mortality greater than 10%, including Mexico (+ 38·8% for IHD, + 34·9% for diabetes), Guatemala (+ 30·0% for IHD, + 10·2% for CVD, + 39·7% for diabetes), Cuba (+ 18·8% for diabetes), Brazil (+ 12·9% for diabetes), the USA (+ 15·1% for diabetes), Slovenia (+ 33·8% for diabetes), Poland (+ 30·2% for IHD, + 19·5% for CVD, + 26 1% for diabetes), Estonia (+ 26·9% for CVD, + 34·7% for diabetes), Bulgaria (+ 22·8% for IHD, + 11·4% for diabetes), Spain (+ 19·7% for diabetes), Italy (+ 18·0% for diabetes), Lithuania (+ 17·6% for diabetes), Finland (+ 13·2% for diabetes) and Georgia (+ 10·7% for IHD, + 19·0% for diabetes). In 2020, 22 out of 30 countries had a significant increase in total mortality. Some of this excess was attributed to COVID-19, but a substantial increase was also observed in deaths attributed to cardiovascular diseases and diabetes.

Using autopsies to dissect COVID-19 pathogenesis

The emergence of SARS-CoV-2 has resulted in millions of deaths as a result of COVID-19. Suitable models were missing at the beginning of the pandemic, and studies investigating disease pathogenesis relied on patients who had succumbed to COVID-19. Since then, autopsies of patients have substantially contributed to our understanding of the pathogenesis of COVID-19 and associated major organ complications. Here we summarize how autopsies have complemented experimental studies, mainly in animal models, and how they have facilitated critical knowledge of COVID-19 to improve daily clinical practice and develop therapeutic interventions. Employing advanced histopathologic and molecular genetic methods in post-mortem tissues, the COVID-19 pandemic has highlighted the importance of autopsies for virology research and clinical practice in current and emerging infectious diseases.

Neutrophil extracellular traps and long COVID

Post-acute COVID-19 sequelae, commonly known as long COVID, encompasses a range of systemic symptoms experienced by a significant number of COVID-19 survivors. The underlying pathophysiology of long COVID has become a topic of intense research discussion. While chronic inflammation in long COVID has received considerable attention, the role of neutrophils, which are the most abundant of all immune cells and primary responders to inflammation, has been unfortunately overlooked, perhaps due to their short lifespan. In this review, we discuss the emerging role of neutrophil extracellular traps (NETs) in the persistent inflammatory response observed in long COVID patients. We present early evidence linking the persistence of NETs to pulmonary fibrosis, cardiovascular abnormalities, and neurological dysfunction in long COVID. Several uncertainties require investigation in future studies. These include the mechanisms by which SARS-CoV-2 brings about sustained neutrophil activation phenotypes after infection resolution; whether the heterogeneity of neutrophils seen in acute SARS-CoV-2 infection persists into the chronic phase; whether the presence of autoantibodies in long COVID can induce NETs and protect them from degradation; whether NETs exert differential, organ-specific effects; specifically which NET components contribute to organ-specific pathologies, such as pulmonary fibrosis; and whether senescent cells can drive NET formation through their pro-inflammatory secretome in long COVID. Answering these questions may pave the way for the development of clinically applicable strategies targeting NETs, providing relief for this emerging health crisis.

Immunopathogenesis and immunomodulatory therapy for myocarditis

Myocarditis is an inflammatory cardiac disease characterized by the destruction of myocardial cells, infiltration of interstitial inflammatory cells, and fibrosis, and is becoming a major public health concern. The aetiology of myocarditis continues to broaden as new pathogens and drugs emerge. The relationship between immune checkpoint inhibitors, severe acute respiratory syndrome coronavirus 2, vaccines against coronavirus disease-2019, and myocarditis has attracted increased attention. Immunopathological processes play an important role in the different phases of myocarditis, affecting disease occurrence, development, and prognosis. Excessive immune activation can induce severe myocardial injury and lead to fulminant myocarditis, whereas chronic inflammation can lead to cardiac remodelling and inflammatory dilated cardiomyopathy. The use of immunosuppressive treatments, particularly cytotoxic agents, for myocarditis, remains controversial. While reasonable and effective immunomodulatory therapy is the general trend. This review focuses on the current understanding of the aetiology and immunopathogenesis of myocarditis and offers new perspectives on immunomodulatory therapies.

SARS-CoV-2 infection is associated with anti-desmoglein 2 autoantibody detection

Post-acute cardiac sequelae, following SARS-CoV-2 infection, are well recognized as complications of COVID-19. We have previously shown the persistence of autoantibodies against antigens in skin, muscle, and heart in individuals following severe COVID-19; the most common staining on skin tissue displayed an inter-cellular cement pattern consistent with antibodies against desmosomal proteins. Desmosomes play a critical role in maintaining the structural integrity of tissues. For this reason, we analyzed desmosomal protein levels and the presence of anti-desmoglein (DSG) 1, 2, and 3 antibodies in acute and convalescent sera from patients with COVID-19 of differing clinical severity. We find increased levels of DSG2 protein in sera from acute COVID-19 patients. Furthermore, we find that DSG2 autoantibody levels are increased significantly in convalescent sera following severe COVID-19 but not in hospitalized patients recovering from influenza infection or healthy controls. Levels of autoantibody in sera from patients with severe COVID-19 were comparable to levels in patients with non-COVID-19-associated cardiac disease, potentially identifying DSG2 autoantibodies as a novel biomarker for cardiac damage. To determine if there was any association between severe COVID-19 and DSG2, we stained post-mortem cardiac tissue from patients who died from COVID-19 infection. This confirmed DSG2 protein within the intercalated discs and disruption of the intercalated disc between cardiomyocytes in patients who died from COVID-19. Our results reveal the potential for DSG2 protein and autoimmunity to DSG2 to contribute to unexpected pathologies associated with COVID-19 infection.

Viral Heart Disease: Diagnosis, Management, and Mechanisms

"Viral heart disease" is a term encompassing numerous virus-triggered heart conditions, wherein cardiac myocytes are injured, causing contractile dysfunction, cell death, or both. Cardiotropic viruses may also damage interstitial cells and vascular cells. Clinical presentation of the disorder varies widely. In most cases, patients are asymptomatic. Presentation includes-but is not limited to-flu-like symptoms, chest pain, cardiac arrhythmias, heart failure, cardiogenic shock, and sudden cardiac death. Laboratory studies, including blood-based heart injury indicators and cardiac imaging, may be needed. Management of viral heart disease requires a graded approach. Watchful observation at home may be the first step. Closer observation, with additional testing such as echocardiography in the clinic or hospital is less common yet may inform the use of cardiac magnetic resonance imaging. Intensive care may be indicated in severe acute illness. Viral heart disease mechanisms are complex. Initially, damage is predominantly virus mediated, whereas, in the second week, immune responses bring unintended obverse consequences for the myocardium. Innate immunity is largely beneficial in initial attempts to quell viral replication, whereas adaptive immunity brings helpful and antigen-specific mechanisms to fight the pathogen but also introduces the capability of autoimmunity. Each cardiotropic virus family has its own pathogenesis signature, including attack on myocytes, vascular cells, and other constitutive cells of myocardial interstitium. The stage of disease and preponderant viral pathways lend opportunities for potential intervention but also the likelihood of uncertainty about management. Overall, this review provides a novel glimpse into the depth of and need for solutions in viral heart disease.

Cell-Specific Mechanisms in the Heart of COVID-19 Patients

From the onset of the pandemic, evidence of cardiac involvement in acute COVID-19 abounded. Cardiac presentations ranged from arrhythmias to ischemia, myopericarditis/myocarditis, ventricular dysfunction to acute heart failure, and even cardiogenic shock. Elevated serum cardiac troponin levels were prevalent among hospitalized patients with COVID-19; the higher the magnitude of troponin elevation, the greater the COVID-19 illness severity and in-hospital death risk. Whether these consequences were due to direct SARS-CoV-2 infection of cardiac cells or secondary to inflammatory responses steered early cardiac autopsy studies. SARS-CoV-2 was reportedly detected in endothelial cells, cardiac myocytes, and within the extracellular space. However, findings were inconsistent and different methodologies had their limitations. Initial autopsy reports suggested that SARS-CoV-2 myocarditis was common, setting off studies to find and phenotype inflammatory infiltrates in the heart. Nonetheless, subsequent studies rarely detected myocarditis. Microthrombi, cardiomyocyte necrosis, and inflammatory infiltrates without cardiomyocyte damage were much more common. In vitro and ex vivo experimental platforms have assessed the cellular tropism of SARS-CoV-2 and elucidated mechanisms of viral entry into and replication within cardiac cells. Data point to pericytes as the primary target of SARS-CoV-2 in the heart. Infection of pericytes can account for the observed pericyte and endothelial cell death, innate immune response, and immunothrombosis commonly observed in COVID-19 hearts. These processes are bidirectional and synergistic, rendering a definitive order of events elusive. Single-cell/nucleus analyses of COVID-19 myocardial tissue and isolated cardiac cells have provided granular data about the cellular composition and cell type-specific transcriptomic signatures of COVID-19 and microthrombi-positive COVID-19 hearts. Still, much remains unknown and more in vivo studies are needed. This review seeks to provide an overview of the current understanding of COVID-19 cardiac pathophysiology. Cell type-specific mechanisms and the studies that provided such insights will be highlighted. Given the unprecedented pace of COVID-19 research, more mechanistic details are sure to emerge since the writing of this review. Importantly, our current knowledge offers significant clues about the cardiac pathophysiology of long COVID-19, the increased postrecovery risk of cardiac events, and thus, the future landscape of cardiovascular disease.

More than a key-the pathological roles of SARS-CoV-2 spike protein in COVID-19 related cardiac injury

Cardiac injury is common in hospitalized coronavirus disease 2019 (COVID-19) patients and cardiac abnormalities have been observed in a significant number of recovered COVID-19 patients, portending long-term health issues for millions of infected individuals. To better understand how Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2, CoV-2 for short) damages the heart, it is critical to fully comprehend the biology of CoV-2 encoded proteins, each of which may play multiple pathological roles. For example, CoV-2 spike glycoprotein (CoV-2-S) not only engages angiotensin converting enzyme II (ACE2) to mediate virus infection but also directly activates immune responses. In this work, the goal is to review the known pathological roles of CoV-2-S in the cardiovascular system, thereby shedding lights on the pathogenesis of COVID-19 related cardiac injury.

COVID-19 mRNA Vaccines: The Molecular Basis of Some Adverse Events

Each injection of any known vaccine results in a strong expression of pro-inflammatory cytokines. This is the result of the innate immune system activation, without which no adaptive response to the injection of vaccines is possible. Unfortunately, the degree of inflammation produced by COVID-19 mRNA vaccines is variable, probably depending on genetic background and previous immune experiences, which through epigenetic modifications could have made the innate immune system of each individual tolerant or reactive to subsequent immune stimulations.We hypothesize that we can move from a limited pro-inflammatory condition to conditions of increasing expression of pro-inflammatory cytokines that can culminate in multisystem hyperinflammatory syndromes following COVID-19 mRNA vaccines (MIS-V). We have graphically represented this idea in a hypothetical inflammatory pyramid (IP) and we have correlated the time factor to the degree of inflammation produced after the injection of vaccines. Furthermore, we have placed the clinical manifestations within this hypothetical IP, correlating them to the degree of inflammation produced. Surprisingly, excluding the possible presence of an early MIS-V, the time factor and the complexity of clinical manifestations are correlated to the increasing degree of inflammation: symptoms, heart disease and syndromes (MIS-V).

Physical Therapy for Adults with Heart Failure

Heart failure (HF) is a complex clinical syndrome caused by structural and/or functional abnormalities that results in significant disease burdens not only to the patients and their families but also to the society. Common symptoms/signs of HF include dyspnea, fatigue, and exercise intolerance, which significantly reduce the quality of life of individuals. Since the coronavirus disease 2019 (COVID-19) pandemic in 2019, it has been found that individuals with cardiovascular disease are more vulnerable to COVID-19-related cardiac sequelae including HF. In this article, we review the updated diagnosis, classifications, and interventional guidelines of HF. We also discuss the link between COVID-19 and HF. The latest evidence about physical therapy for patients with HF in both the stable chronic phase and acute cardiac decompensation phase is reviewed. Physical therapy for HF patients with circulatory support devices is also described.

May 2022 acute hepatitis outbreak, is there a role for COVID-19 and other viruses?

There has been an increasing number of reported cases of acute hepatitis of unknown origin in previously healthy children since first reported on March 31, 2022. This clinical syndrome is identified by jaundice and markedly elevated liver enzymes with increased aspartate transaminase and/or alanine aminotransaminase (greater than 500 IU/L). We conducted an inclusive literature review with respect to acute hepatitis outbreaks in children using the search terms acute hepatitis, outbreak, children, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), coronavirus disease 2019 (COVID-19), and adenovirus. According to the cumulative data presented in four main studies, the median age is 4 years, with a male predominance (1.3:1). Jaundice was the most common clinical manifestation (69%), followed by vomiting (63%), anorexia (52.9%), diarrhea (47.2%), abdominal pain (39%), pyrexia (33.3%), pale stool (30%), and dark urine (30%). Coryza and lethargy were reported in 16.6%, while pruritus was reported in 2% of cases. Acute liver failure was observed in 25% of cases. The exact mechanism of this acute hepatitis outbreak is still not entirely clear. Adenoviruses and SARS-CoV-2 were detected in a significant number of patients. Coinfection with adenovirus and SARS-CoV-2 could be a possible underlying mechanism. However, other possible infections and mechanisms must be considered in the pathogenesis of this condition. Acute hepatitis of unknown origin in children has been a serious problem since the start of the COVID-19 pandemic but has not yet been sufficiently addressed. Many questions remain regarding the underlying mechanisms leading to acute liver failure in children, and it is likely that extensive future research is needed.

Cardiac recovery from COVID-19-associated fulminant myocarditis by extracorporeal biventricular assist

We report a case of cardiac recovery from coronavirus disease 2019 (COVID-19)-associated fulminant myocarditis in a 48-year-old woman diagnosed with COVID-19 infection 4 days before, whose hemodynamic collapse were resuscitated first with venoarterial extracorporeal membranous oxygenation, followed by escalation to extracorporeal biventricular assist devices (ex-BiVAD) using two centrifugal pumps and an oxygenator. She was likely to be multisystem inflammatory syndrome in adults (MIS-A) negative. Cardiac contractility gradually recovered after the 9th day of ex-BiVAD support, and the patient was successfully weaned from ex-BiVAD on the 12th day of support. Due to postresuscitation encephalopathy, she was transferred to the referral hospital for rehabilitation with recovered cardiac function. The histopathology of the myocardial tissue showed smaller amounts of lymphocytes and more infiltration of macrophages. It is important to recognize two phenotypes of MIS-A+ or MIS-A-, with distinct manifestations and outcomes. It is also important to refer urgently such patients with COVID-19-associated fulminant myocarditis, showing different histopathology from usual viral myocarditis, with evolution toward refractory cardiogenic shock to a center with capability for advanced mechanical support to avoid a too-late cannulation.

Learning objective

We should recognize the clinical course and histopathology of the multisystem inflammatory syndrome in adults phenotype of coronavirus disease 2019-associated fulminant myocarditis. We should urgently refer such patients with evolution toward refractory cardiogenic shock to a center with capability for advanced mechanical support, such as venoarterial extracorporeal membrane oxygenation, Impella (Abiomed, Danvers, MA, USA), and extracorporeal biventricular assist devices.

Comparison of Cardiovascular Pathology In Animal Models of SARS-CoV-2 Infection: Recommendations Regarding Standardization of Research Methods

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged as the viral pathogen that led to the global COVID-19 pandemic that began in late 2019. Because SARS-CoV-2 primarily causes a respiratory disease, much research conducted to date has focused on the respiratory system. However, SARS-CoV-2 infection also affects other organ systems, including the cardiovascular system. In this critical analysis of published data, we evaluate the evidence of cardiovascular pathology in human patients and animals. Overall, we find that the presence or absence of cardiovascular pathology is reported infrequently in both human autopsy studies and animal models of SARS-CoV-2 infection. Moreover, in those studies that have reported cardiovascular pathology, we identified issues in their design and execution that reduce confidence in the conclusions regarding SARS-CoV-2 infection as a cause of significant cardiovascular pathology. Throughout this overview, we expand on these limitations and provide recommendations to ensure a high level of scientific rigor and reproducibility.

The impact of COVID-19 and COVID vaccination on cardiovascular outcomes

COVID-19 is an independent risk factor for cardiovascular disease. COVID-19 vaccination may prevent this, but in some cases, COVID-19 vaccination may cause myocarditis or pericarditis. Patients with COVID-19 may present with non-specific symptoms that have a cardiac origin. This review examines the cardiovascular complications of COVID-19 infection and the impact of COVID-19 vaccination. COVID-19 cardiovascular complications include myocardial injury, pericarditis, coagulopathy, myocardial infarction, heart failure, arrhythmias, and persistent post-acute risk of adverse cardiovascular outcomes. Diagnostic and referral pathways for non-specific symptoms, such as dyspnoea and fatigue, remain unclear. COVID-19 vaccination is cardioprotective overall but is associated with myopericarditis in young males, though at a lower rate than following SARS-CoV-2 infection. Increased awareness among primary care physicians of potential cardiovascular causes of non-specific post-COVID-19 symptoms, including in younger adults, such as fatigue, dyspnoea, and chest pain, is essential. We recommend full vaccination with scheduled booster doses, optimal management of cardiovascular risk factors, rapid treatment of COVID-19, and clear diagnostic, referral, and management pathways for patients presenting with non-specific symptoms to rule out cardiac complications.