COVID-19 and the Cardiovascular System. Crit Care Nurs Q. 2020;43:381-389. [PMID: 32833774 DOI: 10.1097/cnq.0000000000000323]

Development of a novel human CD147 knock-in NSG mouse model to test SARS-CoV-2 viral infection

BACKGROUND

An animal model that can mimic the SARS-CoV-2 infection in humans is critical to understanding the rapidly evolving SARS-CoV-2 virus and for development of prophylactic and therapeutic strategies to combat emerging mutants. Studies show that the spike proteins of SARS-CoV and SARS-CoV-2 bind to human angiotensin-converting enzyme 2 (hACE2, a well-recognized, functional receptor for SARS-CoV and SARS-CoV-2) to mediate viral entry. Several hACE2 transgenic (hACE2Tg) mouse models are being widely used, which are clearly invaluable. However, the hACE2Tg mouse model cannot fully explain: (1) low expression of ACE2 observed in human lung and heart, but lung or heart failure occurs frequently in severe COVID-19 patients; (2) low expression of ACE2 on immune cells, but lymphocytopenia occurs frequently in COVID-19 patients; and (3) hACE2Tg mice do not mimic the natural course of SARS-CoV-2 infection in humans. Moreover, one of most outstanding features of coronavirus infection is the diversity of receptor usage, which includes the newly proposed human CD147 (hCD147) as a possible co-receptor for SARS-CoV-2 entry. It is still debatable whether CD147 can serve as a functional receptor for SARS-CoV-2 infection or entry.

RESULTS

Here we successfully generated a hCD147 knock-in mouse model (hCD147KI) in the NOD-scid IL2Rgammanull (NSG) background. In this hCD147KI-NSG mouse model, the hCD147 genetic sequence was placed downstream of the endogenous mouse promoter for mouse CD147 (mCD147), which creates an in vivo model that may better recapitulate physiological expression of hCD147 proteins at the molecular level compared to the existing and well-studied K18-hACE2-B6 (JAX) model. In addition, the hCD147KI-NSG mouse model allows further study of SARS-CoV-2 in the immunodeficiency condition which may assist our understanding of this virus in the context of high-risk populations in immunosuppressed states. Our data show (1) the human CD147 protein is expressed in various organs (including bronchiolar epithelial cells) in hCD147KI-NSG mice by immunohistochemical staining and flow cytometry; (2) hCD147KI-NSG mice are marginally sensitive to SARS-CoV-2 infection compared to WT-NSG littermates characterized by increased viral copies by qRT-PCR and moderate body weight decline compared to baseline; (3) a significant increase in leukocytes in the lungs of hCD147KI-NSG mice, compared to infected WT-NSG mice.

CONCLUSIONS

hCD147KI-NSG mice are more sensitive to COVID-19 infection compared to WT-NSG mice. The hCD147KI-NSG mouse model can serve as an additional animal model for further interrogation whether CD147 serve as an independent functional receptor or accessory receptor for SARS-CoV-2 entry and immune responses.

Association of Congenital and Acquired Cardiovascular Conditions With COVID-19 Severity Among Pediatric Patients in the US

IMPORTANCE

Identifying the associations between severe COVID-19 and individual cardiovascular conditions in pediatric patients may inform treatment.

OBJECTIVE

To assess the association between previous or preexisting cardiovascular conditions and severity of COVID-19 in pediatric patients.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study used data from a large, multicenter, electronic health records database in the US. The cohort included patients aged 2 months to 17 years with a laboratory-confirmed diagnosis of COVID-19 or a diagnosis code indicating infection or exposure to SARS-CoV-2 at 85 health systems between March 1, 2020, and January 31, 2021.

EXPOSURES

Diagnoses for 26 cardiovascular conditions between January 1, 2015, and December 31, 2019 (before infection with SARS-CoV-2).

MAIN OUTCOMES AND MEASURES

The main outcome was severe COVID-19, defined as need for supplemental oxygen or in-hospital death. Mixed-effects, random intercept logistic regression modeling assessed the significance and magnitude of associations between 26 cardiovascular conditions and COVID-19 severity. Multiple comparison adjustment was performed using the Benjamini-Hochberg false discovery rate procedure.

RESULTS

The study comprised 171 416 pediatric patients; the median age was 8 years (IQR, 2-14 years), and 50.28% were male. Of these patients, 17 065 (9.96%) had severe COVID-19. The random intercept model showed that the following cardiovascular conditions were associated with severe COVID-19: cardiac arrest (odds ratio [OR], 9.92; 95% CI, 6.93-14.20), cardiogenic shock (OR, 3.07; 95% CI, 1.90-4.96), heart surgery (OR, 3.04; 95% CI, 2.26-4.08), cardiopulmonary disease (OR, 1.91; 95% CI, 1.56-2.34), heart failure (OR, 1.82; 95% CI, 1.46-2.26), hypotension (OR, 1.57; 95% CI, 1.38-1.79), nontraumatic cerebral hemorrhage (OR, 1.54; 95% CI, 1.24-1.91), pericarditis (OR, 1.50; 95% CI, 1.17-1.94), simple biventricular defects (OR, 1.45; 95% CI, 1.29-1.62), venous embolism and thrombosis (OR, 1.39; 95% CI, 1.11-1.73), other hypertensive disorders (OR, 1.34; 95% CI, 1.09-1.63), complex biventricular defects (OR, 1.33; 95% CI, 1.14-1.54), and essential primary hypertension (OR, 1.22; 95% CI, 1.08-1.38). Furthermore, 194 of 258 patients (75.19%) with a history of cardiac arrest were younger than 12 years.

CONCLUSIONS AND RELEVANCE

The findings suggest that some previous or preexisting cardiovascular conditions are associated with increased severity of COVID-19 among pediatric patients in the US and that morbidity may be increased among individuals children younger than 12 years with previous cardiac arrest.

Analysis of the Evolution of User Emotion and Opinion Leaders' Information Dissemination Behavior in the Knowledge Q&A Community during COVID-19

Since its emergence in 2019, COVID-19 has quickly triggered widespread public discussion on social media. From 26 February 2020 to 26 September 2020, this study collected data on COVID-19-related posts in the knowledge Q&A community, identified 220 opinion leaders of this community, and used social network analysis and sentiment analysis to analyze the information exchange behavior and emotional evolution of the opinion leaders during COVID-19. The results show that the COVID-19 topic community could be divided into seven main categories. The information dissemination of opinion leader information dissemination network had low efficiency, multiple paths, and a high degree of control. In addition, the emotional evolution of users showed obvious phased characteristics. User emotion changed from initially strong negative to strong positive over the course of the pandemic and eventually tended to be objective and neutral as time passed and the event stabilized.

Development of a Novel Human CD147 Transgenic NSG Mouse Model to test SARS-CoV-2 Infection and Immune Responses

An animal model that can mimic the SARS-CoV-2 infection in humans is critical to understanding the newly emerged, rapidly spreading SARS-CoV-2 and development of therapeutic strategies. Studies show that the spike (S) proteins of SARS-CoV (SARS-CoV-S-1-S) and SARS-CoV-2 (SARS-CoV-2-S) bind to human angiotensin-converting enzyme 2 (hACE2, a well-recognized, functional receptor for SARS-CoV and SARS-CoV-2) to mediate viral entry. Several hACE2 transgenic (hACE2Tg) mouse models are being widely used, which is clearly invaluable. However, the hACE2Tg mouse model cannot fully explain: 1) low expression of ACE2 observed in human lung and heart, but lung or heart failure occurs frequently in severe COVID-19 patients); 2) low expression of ACE2 on immune cells, but lymphocytopenia occurs frequently in COVID-19 patients; and 3) hACE2Tg mice do not develop strong clinical disease following SARS-CoV-2 infection in contrast to SARS-CoV-1. Moreover, one of most outstanding features of coronaviruses is the diversity of receptor usage, which includes the newly proposed human CD147 (hCD147) as a receptor for SARS-CoV-2-S. It is still debatable whether CD147 can serve as a functional receptor for SARS-CoV-2 infection or entry. Here we successfully generated a hCD147Tg mouse model in the NOD-scid IL2Rgamma^null (NSG) background. In this hCD147Tg-NSG mouse model, the hCD147 genetic sequence was placed following the endogenous mouse promoter for mouse CD147 (mCD147), which creates an in vivo model that may better recapitulate physiological expression of CD147 proteins at the molecular level compared to the existing and well-studied K18-hACE2-B6 model. In addition, the hCD147Tg-NSG mouse model allows further study of SARS-CoV-2 in the immunodeficiency condition which may assist our understanding of this virus in the context of high-risk populations with immunosuppressed conditions. The hCD147Tg-NSG mouse mode can serve as an additional animal model for interrogate whether CD147 serve as an independent functional receptor or accessory receptor for SARS-CoV-2 entry and immune responses.

A super learner ensemble of 14 statistical learning models for predicting COVID-19 severity among patients with cardiovascular conditions

BACKGROUND

Cardiovascular and other circulatory system diseases have been implicated in the severity of COVID-19 in adults. This study provides a super learner ensemble of models for predicting COVID-19 severity among these patients.

METHOD

The COVID-19 Dataset of the Cerner Real-World Data was used for this study. Data on adult patients (18 years or older) with cardiovascular diseases between 2017 and 2019 were retrieved and a total of 13 of these conditions were identified. Among these patients, 33,042 admitted with positive diagnoses for COVID-19 between March 2020 and June 2020 (from 59 hospitals) were identified and selected for this study. A total of 14 statistical and machine learning models were developed and combined into a more powerful super learning model for predicting COVID-19 severity on admission to the hospital.

RESULT

LASSO regression, a full extreme gradient boosting model with tree depth of 2, and a full logistic regression model were the most predictive with cross-validated AUROCs of 0.7964, 0.7961, and 0.7958 respectively. The resulting super learner ensemble model had a cross validated AUROC of 0.8006 (range: 0.7814, 0.8163). The unbiased AUROC of the super learner model on an independent test set was 0.8057 (95% CI: 0.7954, 0.8159).

CONCLUSION

Highly predictive models can be built to predict COVID-19 severity of patients with cardiovascular and other circulatory conditions. Super learning ensembles will improve individual and classical ensemble models significantly.

Cardiovascular impact of COVID-19 with a focus on children: A systematic review

BACKGROUND

Since the beginning of the pandemic, coronavirus disease-2019 (COVID-19) in children has shown milder cases and a better prognosis than adults. Although the respiratory tract is the primary target for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), cardiovascular involvement is emerging as one of the most significant and life-threatening complications of SARS-CoV-2 infection in adults.

AIM

To summarize the current knowledge about the potential cardiovascular involvement in pediatric COVID-19 in order to give a perspective on how to take care of them during the current pandemic emergency.

METHODS

Multiple searches in MEDLINE, PubMed were performed using the search terms "COVID-19" or "SARS-CoV-2" were used in combination with "myocardial injury" or "arrhythmia" or "cardiovascular involvement" or "heart disease" or "congenital heart disease" or "pulmonary hypertension" or "long QT" or "cardiomyopathies" or "channelopathies" or "Multisystem inflammatory system" or "PMIS" or "MIS-C" or "Pediatric multisystem inflammatory syndrome" or "myocarditis" or "thromboembolism to identify articles published in English language from January 1st, 2020 until July 31st, 2020. The websites of World Health Organization, Centers for Disease control and Prevention, and the Johns Hopkins Coronavirus Resource Center were reviewed to provide up to date numbers and infection control recommendations. Reference lists from the articles were reviewed to identify additional pertinent articles. Retrieved manuscripts concerning the subject were reviewed by the authors, and the data were extracted using a standardized collection tool. Data were subsequently analyzed with descriptive statistics. For Pediatric multisystemic inflammatory syndrome temporally associated with COVID-19 (PMIS), multiple meta-analyses were conducted to summarize the pooled mean proportion of different cardiovascular variables in this population in pseudo-cohorts of observed patients.

RESULTS

A total of 193 articles were included. Most publications used in this review were single case reports, small case series, and observational small-sized studies or literature reviews. The meta-analysis of 16 studies with size > 10 patients and with complete data about cardiovascular involvement in children with PMIS showed that PMIS affects mostly previously healthy school-aged children and adolescents presenting with Kawasaki disease-like features and multiple organ failure with a focus on the heart, accounting for most cases of pediatric COVID-19 mortality. They frequently presented cardiogenic shock (53%), ECG alterations (27%), myocardial dysfunction (52%), and coronary artery dilation (15%). Most cases required PICU admission (75%) and inotropic support (57%), with the rare need for extracorporeal membrane oxygenation (4%). Almost all of these children wholly recovered in a few days, although rare deaths have been reported (2%). Out of PMIS cases we identified 10 articles reporting sporadic cases of myocarditis, pulmonary hypertension and cardiac arrythmias in previously healthy children. We also found another 10 studies reporting patients with pre-existing heart diseases. Most cases consisted in children with severe COVID-19 infection with full recovery after intensive care support, but cases of death were also identified. The management of different cardiac conditions are provided based on current guidelines and expert panel recommendations.

CONCLUSION

There is still scarce data about the role of cardiovascular involvement in COVID-19 in children. Based on our review, children (previously healthy or with pre-existing heart disease) with acute COVID-19 requiring hospital admission should undergo a cardiac workup and close cardiovascular monitoring to identify and treat timely life-threatening cardiac complications.