Myocardial Injury in COVID-19 (Epidemiology, Influence on Prognosis, Pathogenesis, Treatment)

Abstract

COVID-19 is a multiple organ illness. Approximately 2 years after its emergence, SARS-CoV-2 is considered a viral pathogen affecting the vasculature and potentially generating myocardial injury.This chapter synthesizes data regarding myocardial injury, its definition, epidemiology, pathogenesis, diagnosis, and treatment, as well as its impact on COVID-19 prognosis.According to current guidelines, the term myocardial injury applies to any patient in whom at least one cardiac troponin (cTn) concentration is above the 99th percentile upper reference limit. COVID-19 patients with troponin increases suggesting myocardial injury should be classified as acute non-ischemic myocardial injury, chronic myocardial injury, or acute myocardial infarction. All recent data suggest that acute non-ischemic myocardial injury is the predominant cause for cTn increases in patients with COVID-19.Incidence of myocardial injury as a COVID-19 related complication is reported in different studies up to 36%. Myocardial injury in COVID-19 patients is predictive of adverse outcomes. Thus, prevalence of cardiac dysfunction might reach 70% of patients with COVID-19 in the intensive care unit.Pathogenesis of myocardial injury in COVID-19 is not completely understood. Different mechanisms have been proposed, such as: the ineffective adaptation of the cardiovascular system to the increased demand of a severe viral illness; the decrease of systemic oxygenation during pneumonia; the direct viral myocardial injury with local infection of the myocardium; the immune dysregulation, the latter being probably the most important.Several biomarkers (CRP, serum amyloid A, Il-6, LDH, neutrophil-to-lymphocyte ratio, D-dimers, cardiac troponin, NT-pro BNP, renal biomarkers, lymphocytes, and platelet count) are very useful in monitoring the evolution of COVID-19 patients with myocardial injury. Nevertheless, the levels of these biomarkers are influenced by factors such as hypoxia or renal function. Therefore, diagnosis of myocardial injury and myocarditis should be a complex one, including clinical factors and several methods (ECG, cardiac ultrasound, CMR, cardiac angiography, and cardiac CT).Treatment of COVID-19 patients with myocardial injury should focus on general and symptomatic treatment, antiviral treatment, respiratory failure treatment, circulatory support, antibacterial treatment for secondary infections, cytokine storm treatment, and corticoid treatment in severe patients.Prognostically, myocardial injury is independently associated with increased risk of severe evolution and in-hospital mortality. Thus, cTn monitoring should be used in COVID-19 as guiding tool for key clinical decisions in critically ill patients.KeywordsCOVID-19Myocardial injuryCardiac troponinPrognosis