Mechanisms and management of prothrombotic state in COVID-19 disease

Abstract

The novel severe acute respiratory syndrome viral disease outbreak due to SARS-CoV-2 is a rapidly evolving disease and represents one of the greatest medical challenges in recent times. It is believed that SARS-CoV-2 has migrated from bats to an intermediate host and then to humans. This article aims at the mechanism and management of prothrombotic state in COVID-19 positive patients. We tried to present how the SARS-CoV-2 virus can induce thromboembolic events and the incidence of these thromboembolic events. We also tried to depict anticoagulation management in these patients as well as postdischarge plan and follow-up. Invasion of type 2 pneumocytes by the SARS-CoV-2 virus is critical in the course of illness because it results in activation of immune cells leading to elevation of cytokines. The subsequent activation of T cells and macrophages infiltrates the infected myocardial cells causing direct myocardiocyte toxicity and development of arrhythmia. Hypoxia or hypotension during the clinical course causes a mismatch between myocyte oxygen supply and workload demand resulting in cardiac distress. SARS-CoV-2 affects endothelial cells and pericytes that lead to severe micro and macrovascular dysfunction, and together with oxygen supply-demand mismatch, immune hyperresponsivity can potentially cause destabilization and plaque rupture causing acute coronary syndromes. Other mechanisms of injury include myocarditis, pericarditis, stress cardiomyopathy, vasculitis, and DIC (Disseminated intravascular coagulation)/microthrombi. SARS-CoV-2 enters the cells by the Spike protein S whose surface unit, S1, binds to the ACE2 receptor on the host cell. The type II transmembrane serine proteases TMPRSS2 and histone acetyltransferases (HAT) are host cell proteases that are recruited by the virus to cleave ACE2 surface protein S which facilitates the viral entry. Therefore, TMPRSS2 and HAT could be targeted for potential drugs against SARS-CoV-2. SARS-CoV-2 uses an RNA-dependent RNA polymerase for proliferation, which is targeted by remdesivir that is currently approved for emergency use by Food and Drug Administration (FDA). We need to adopt a multifaceted approach when combating SARS-CoV-2 because it presents several challenges including medical, psychological, socioeconomic, and ethical. COVID-19 is the biggest calamity during the 21st century, we need to have a keen understanding of its pathophysiology and clinical implications for the development of preventive measures and therapeutic modalities.

Keywords: COVID-19; anticoagulation of choice; cardiovascular complications; prothrombotic state.

Figure 1.

Pathophysiology of SARS-CoV-2 mediated cardiac injury-key manifestations.

Figure 2.

SARS-CoV-2 invasion into host cells.

Figure 3.

Mechanism of action of tocilizumab. GM-CSF, granulocyte-macrophage-colony stimulating factor; Gp130, glycoprotein 130; IL-6, interleukin 6; MCP1, monocyte chemoattractant protein-1; mIL-6R, membrane interleukin-6 receptor.