BREAKING! COVID-19 News: Researchers Find SARS-CoV-2 Virus Particles In Heart Tissues Of Deceased COVID-19 Patients Indicating It Attacks Hearts Directly!
: A new research from the University of Milan have identified the presence of SARS-CoV-2 in the heart tissue of deceased COVID-19 patients who had died from respiratory failure, without showing any signs of cardiac involvement.
The study showed that the SAR-CoV-2 coronavirus was present in the cardiomyocytes of all six deceased patients who had gone through autopsy, and that active viral transcription of RNA for the viral spike protein had occurred. The spike protein is the surface structure SARS-CoV-2 uses to bind to and access host cells.
The study findings were published on a preprint server and have not been peer-reviewed. https://www.medrxiv.org/content/10.1101/2020.08.24.20170175v1
Despite the fact that past studies showed that the heart was also affected by the COVID-19 disease, there was no real documented proof to show that the virus directly attacked the heart muscles, it was merely assumed. But the new study findings is causing alarm among medical circles as it has various implications in clinical care and also for recovered patients.
The study showed that the injury to cardiomyocytes varied, from the absence of cell death and no subcellular alterations to structural abnormalities and intracellular edema.
Dr Gaetano Pietro Bulfamante from University of Milan and colleagues say the findings indicate that guidelines for monitoring COVID-19 survivors once they have been discharged from hospital need to be revised.
Significantly, the long-term cardiovascular outcomes could be similar to those seen in survivors of the 2002 to 2003 SARS-CoV-1 outbreak, where 40% of recovered individuals developed cardiovascular abnormalities over a 12-year follow-up period, the team warns.
COVID-19 mortality is still increasing worldwide and aside from the respiratory illness the virus causes, studies have now shown that several other organs may be involved, including the cardiovascular system.
About 20 and 40% of hospitalized patients experience cardiac symptoms, ranging from chest pain to arrhythmia and cardiogenic shock.
In addition, up to 7% of COVID-related deaths are linked to myocarditis according to Dr Bulfamante.
Till now however it is still not clear whether cardiovascular involvement is due to cells being directly damaged by the virus or whether it is secondary to the involvement of an overreactive immune response. Hypoxia-induced by acute respiratory distress syndrome (ARDS) might also lead to myocardial injury.
However SARS-CoV-2 has been identified in patients’ vascular endothelial cells and the cardiac macrophages of patients with myocarditis.
The study tested for the presence of SARS-CoV-2 in the heart tissue of six patients (aged 54 to 69 years) with COVID-19 who had died from respiratory failure, without showing signs of cardiac involvement.
Utilizing chip-based digital PCR, the team detected SARS-CoV-2 viral RNA in the cardiomyocytes of heart tissue samples taken from all six patients. Using Western blot, immunohistochemistry and immunofluorescence techniques, they also identified vira
l spike protein in the cardiomyocytes and electron microscopy revealed the presence of full virus particles.
A significant and interesting observation was that the researchers found that the expression of the spike protein varied between patients, which led them to the hypothesis that the viral genome was being actively transcribed within the cardiomyocytes.
In order to test for the presence of SARS-CoV-2 as a transcriptionally active virus in the cells, the study team performed an RNAScope assay using two probes that recognize spike protein sense and antisense RNA, to enable distinction between the viral RNA genome and its transcript.
Signals were obtained with both probes for all patient samples, but the most abundant staining was observed for the probe that detected the actively transcribed virus.
The study team say this is the first study to identify the localization of SARS-CoV-2 RNA in cardiomyocytes and the active viral transcription of both sense and antisense RNA for the viral spike protein.
The study team said that the pattern of cardiomyocyte injury varied. Cells containing the virus did not appear to undergo apoptosis but did exhibit intracellular alterations, including increased cell volume and intracellular edema.
Though some cardiomyocytes containing SARS-CoV-2 appeared normal, others showed excessive intracellular area between sarcolemma and sarcomere structure, which the authors say may explain the intracellular edema observed.
Dr Bulfamante said, “Several cardiomyocytes showed an altered cell structure, with increased cell area and intracellular edema, suggesting a cardiomyocyte swelling. This microscopic event may be interpreted as a precocious subclinical sign of cell damage, potentially leading to myocardial interstitial edema formation.”
The study team said the findings has shown that cardiac tissue, including the contractile cell compartment, can be infected by SARS-CoV-2 and that initially, this may cause microscopic cardiomyocyte alterations that do not lead to clinically-relevant macroscopic cardiac damage.
Dr Bulfamante,“Our crucial study specifically suggests the need to redefine post-discharge surveillance guidelines for surviving COVID-19 patients’ follow-up even in the absence of overt cardiac phenotype. The long-term cardiovascular outcome of COVID-19 patients may mirror SARS patients, who developed cardiovascular abnormalities in 40% of recovered cases in a 12-years-long follow-up period.”
It is highly recommended that all recovered COVID-19 patients irrespective of their initial conditions ie whether they suffered mild, moderate or severe symptoms or were merely asymptomatic to keep on having regular health and heart screenings with their doctors and cardiologists.
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