Coronavirus Historical Perspective, Disease Mechanisms, and Clinical Outcomes: JACC Focus Seminar

Abstract

The emergence of a new coronavirus disease (coronavirus disease 2019 [COVID-19]) has raised global concerns regarding the health and safety of a vulnerable population. Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) incites a profound inflammatory response leading to tissue injury and organ failure. COVID-19 is characterized by the bidirectional relationship between inflammation and thrombosis. The clinical syndrome is propelled by inflammation producing acute lung injury, large-vessel thrombosis, and in situ microthrombi that may contribute to organ failure. Myocardial injury is common, but true myocarditis is rare. Elderly patients, those with established cardiovascular disease, and mechanically ventilated patients face the highest mortality risk. Therapies for COVID-19 are evolving. The antiviral drug remdesivir, dexamethasone, transfusion of convalescent plasma, and use of antithrombotic therapy are promising. Most require additional prospective studies. Although most patients recover, those who survive severe illness may experience persistent physical and psychological disabilities.

Keywords: COVID-19; SARS-CoV-2; cardiovascular disease; inflammation; thrombosis.

Graphical abstract

Figure 1

Provisional Death Counts Involving COVID-19 From February 1, 2020, to June 20, 2020, as Reported to the CDC Deaths involving coronavirus disease 2019 (COVID-19) are more prevalent in older age groups. CDC = Centers for Disease Control and Prevention.

Central Illustration

Proposed Severity Levels of Coronavirus Disease 2019 Coronavirus disease (COVID) 2019 produces a spectrum of clinical illness ranging from mild respiratory and constitutional symptoms to pneumonia with severe hypoxia and respiratory failure. Severe illness is associated with systemic inflammation and disturbances in coagulation leading to small- and large-vessel thrombosis. Myocardial injury when present is usually mild but associated with worse outcomes. ALT= alanine aminotransferase; AST = aspartate aminotransferase; CRP = C-reactive protein; ESR = erythrocyte sedimentation rate; FiO₂ = fraction of inspired oxygen; IL = interleukin; INR = international normalized ratio; LV = left ventricular; paO₂ = partial pressure of oxygen; SpO₂ = blood oxygen saturation.