COVID-19: The Heart of the Matter-Pathological Changes and a Proposed Mechanism

The Impact of Cardiovascular Antecedents on the Prognosis of COVID-19 Critically Ill Patients

Background/Objectives: The objective of the study is to analyze the impact of cardiovascular history on mortality in COVID-19 patients, hospitalized in the intensive care unit with indications for continuous positive airway pressure (CPAP) and subsequently mechanical ventilation, without oncological disease. Methods: A retrospective observational study was carried out on a group of 108 critical COVID-19 patients. We compared demographic data, paraclinical and clinical parameters, days of hospitalization, and mortality rate between two groups of patients, one group with a history of cardiovascular disease (81 patients) and a group without a history of cardiovascular disease (27 patients). Results: Patients with cardiovascular antecedents had a higher mortality rate than those without cardiovascular antecedents, presenting severe forms with shorter survival time in the intensive care unit and increased inflammatory evidence. Compared to patients without a history of cardiovascular illness, those with cardiovascular disease had a lower average age, and developed a severe form of COVID-19. Conclusions: Cardiovascular antecedents can worsen the prognosis of patients with COVID-19, requiring a careful screening and multidisciplinary approach.

Post-coronavirus disease 2019 functional impairments, limitations, and restrictions: A prospective cohort study based on the international classification of functioning, disability, and health

Background

Current knowledge regarding coronavirus disease 2019 (COVID-19) is constantly evolving, and the long-term functional impairments, limitations, and restrictions have not yet been well established.

Objective

to evaluate the impact of post-COVID condition on the human functioning through the International Classification of Functioning, Disability and Health (ICF) classification.

Methods

This is a prospective cohort study with 53 individuals with post-COVID condition at 3 time points: 0 to 3 (baseline), 3 to 6, and 6-12 months (follow-up). Outcomes were organized in dichotomous variable: No impairment (0); presence of impairment (≥1) in body function, structure, activities, and participation domains according to the ICF checklist. Chi-square test was used to determine the differences of 3 time points, and association with persistent symptoms.

Results

A statistically significant difference was observed between the periods, with greater disabilities at 6-12 than at 0-3 months in mental, sensory, pain, and movement-related functions; cardiovascular, immunological, and respiratory systems. In terms of activity and participation, a greater limitation at 6-12 months was observed than at 0-3 months in learning and applying knowledge, general tasks, and mobility. In the domain of interpersonal interactions and relationships, there was a statistically significant difference between the 6-12 and 3-6 months groups. Associations between COVID-19 symptoms and ICF components at the first follow-up were: anosmia and dysgeusia with weight maintenance, fatigue and irritability with pain, brain fog with watching and listening, walking difficulty with pain, and headache with pain, watching, and listening. At the second follow-up were: anosmia and dysgeusia with energy and drive functions, attention, memory, and emotional functions; dizziness with watching and listening; fatigue with emotional function, pain, undertaking multiple tasks, lifting and carrying objects, and driving; irritability with energy and drive, emotional function, undertaking multiple tasks, lifting and carrying objects, and walking; walking difficulty with energy and driving, emotional function, respiration, muscle power, cardiovascular system, undertaking multiple tasks, lifting and carrying objects, and walking; and headache with emotional function, watching, and listening.

Conclusions

Individuals with COVID-19 persistent symptoms showed impairments in structure and function, activity limitations, and participation restrictions during the 1-year follow-up period.

Impact of P-selectin-PSGL-1 Axis on Platelet-Endothelium-Leukocyte Interactions in Fatal COVID-19

In critically ill patients infected with SARS-CoV-2, early leukocyte recruitment to the respiratory system was found to be orchestrated by leukocyte trafficking molecules accompanied by massive secretion of proinflammatory cytokines and hypercoagulability. Our study aimed to explore the interplay between leukocyte activation and pulmonary endothelium in different disease stages of fatal COVID-19. Our study comprised 10 COVID-19 postmortem lung specimens and 20 control lung samples (5 acute respiratory distress syndrome, 2 viral pneumonia, 3 bacterial pneumonia, and 10 normal), which were stained for antigens representing the different steps of leukocyte migration: E-selectin, P-selectin, PSGL-1, ICAM1, VCAM1, and CD11b. Image analysis software QuPath was used for quantification of positive leukocytes (PSGL-1 and CD11b) and endothelium (E-selectin, P-selectin, ICAM1, VCAM1). Expression of IL-6 and IL-1β was quantified by RT-qPCR. Expression of P-selectin and PSGL-1 was strongly increased in the COVID-19 cohort compared with all control groups (COVID-19:Controls, 17:23, P < .0001; COVID-19:Controls, 2:75, P < .0001, respectively). Importantly, P-selectin was found in endothelial cells and associated with aggregates of activated platelets adherent to the endothelial surface in COVID-19 cases. In addition, PSGL-1 staining disclosed positive perivascular leukocyte cuffs, reflecting capillaritis. Moreover, CD11b showed a strongly increased positivity in COVID-19 compared with all controls (COVID-19:Controls, 2:89; P = .0002), indicating a proinflammatory immune microenvironment. Of note, CD11b exhibited distinct staining patterns at different stages of COVID-19 disease. Only in cases with very short disease course, high levels of IL-1β and IL-6 mRNA were observed in lung tissue. The striking upregulation of PSGL-1 and P-selectin reflects the activation of this receptor-ligand pair in COVID-19, increasing the efficiency of initial leukocyte recruitment, thus promoting tissue damage and immunothrombosis. Our results show that endothelial activation and unbalanced leukocyte migration play a central role in COVID-19 involving the P-selectin-PSGL-1 axis.

Cardiac Macrophage Density in Covid-19 Infection: Relationship to Myocyte Necrosis and Acute Lung Injury

SARS-Cov-2 infection is not limited to the respiratory tract and can involve other organs including the heart, blood vessels, kidneys, liver, gastrointestinal tract, placenta, and skin. Covid-19 patients with cardiac involvement usually have higher morbidity and mortality compared to those without cardiac involvement. The frequency and the specificity of the myocardial pathological changes in patients who die after documented infection with SARS-Cov-2 is uncertain. Macrophages can be found in the normal heart (interstitium, around the endothelial cells and in the epicardial adipose tissue), and they are considered part of the major immune cell population in the heart. In this case-control autopsy study, we compare the gross and microscopic cardiac findings, and the available clinical characteristics between a group of 10 Covid-19 decedents and a control group of 20 patients who died with non-SARS-Cov-2 severe bronchopneumonia and/or diffuse alveolar damage. The objectives of this semi-quantitative study are to study single myocyte necrosis and its relation to the strain on the heart caused by lung injury as a causative mechanism, and to study the density of myocardial and epicardial macrophages in Covid-19 hearts in comparison to the control group, and in Covid-19 hearts with single myocyte necrosis in comparison to Covid-19 hearts without single myocyte necrosis. Lymphocytic myocarditis was not identified in any of the hearts from the Covid-19 or the control group. Single myocyte necrosis is more frequent in the Covid-19 group compared to the control group, suggesting that it is unrelated to the strain on the heart caused by underlying lung injury. The density of the macrophages in the epicardium and myocardium in the hearts of the Covid-19 group is higher compared to those in the control group. The density of epicardial macrophages is higher in the Covid-19 hearts with single myocyte necrosis than in those without. These observations contribute to our increasing appreciation of the role of macrophages in the pathophysiologic response to infection by SARS-CoV-2.

Immunopathological changes, complications, sequelae and immunological memory in COVID-19 patients

Confirmed SARS-CoV-2-caused disease (COVID-19) cases have reached 275.65 million worldwide. Although the majority of COVID-19 patients present mild to moderate symptoms, some have severe complications including death. We first reviewed the pathogenesis on ACE2, a binding receptor of SARS-CoV-2 expressed in multiple organs, and prevalent multinucleate syncytia in the lung tissues of COVID-19 patients. Then, we evaluated the pathological, immunological changes and sequelae in the major organs. Finally, we reviewed the immunological memory after SARS-CoV-2 infection and vaccination. The binding of SARS-Cov-2 to ACE2 receptor results in reduced ACE2 protein levels, which may lead to elevated susceptibility to inflammation, cell death, organ failure, and potentially severe illness. These damages increase the risk of health problems over a long period, which result in many complications. The complications in multiple organs lead to the increased risk of long-term health problems that require additional attention. A multidisciplinary care team is necessary for further management and recovery of the COVID-19 survivors. Many COVID-19 patients will probably make antibodies against SARS-CoV-2 virus for most of their lives, and the immunity against reinfection would last for 3-61 months.

Long COVID: post-acute sequelae of COVID-19 with a cardiovascular focus

Emerging as a new epidemic, long COVID or post-acute sequelae of coronavirus disease 2019 (COVID-19), a condition characterized by the persistence of COVID-19 symptoms beyond 3 months, is anticipated to substantially alter the lives of millions of people globally. Cardiopulmonary symptoms including chest pain, shortness of breath, fatigue, and autonomic manifestations such as postural orthostatic tachycardia are common and associated with significant disability, heightened anxiety, and public awareness. A range of cardiovascular (CV) abnormalities has been reported among patients beyond the acute phase and include myocardial inflammation, myocardial infarction, right ventricular dysfunction, and arrhythmias. Pathophysiological mechanisms for delayed complications are still poorly understood, with a dissociation seen between ongoing symptoms and objective measures of cardiopulmonary health. COVID-19 is anticipated to alter the long-term trajectory of many chronic cardiac diseases which are abundant in those at risk of severe disease. In this review, we discuss the definition of long COVID and its epidemiology, with an emphasis on cardiopulmonary symptoms. We further review the pathophysiological mechanisms underlying acute and chronic CV injury, the range of post-acute CV sequelae, and impact of COVID-19 on multiorgan health. We propose a possible model for referral of post-COVID-19 patients to cardiac services and discuss future directions including research priorities and clinical trials that are currently underway to evaluate the efficacy of treatment strategies for long COVID and associated CV sequelae.