ABSTRACT
Background: Myocardial injury (MI) is frequent in critically ill patients with COVID-19, but its pathogenesis remains unclear. We hypothesized that MI is not solely due to viral infection by SARS-CoV-2, but rather due to the common pathophysiological mechanisms associated with severe pulmonary infections and respiratory failure. Methods: Contemporary and comparative cohort study designed to compare the incidence of MI in patients with acute respiratory failure caused by COVID-19 to that of patients with other pulmonary infections. In addition, we aim to investigate whether MI is a distinct risk factor for in-hospital mortality in patients with COVID-19-related respiratory failure compared to those with non-COVID-19 infections. Results: The study included 1444 patients with COVID-19 [55.5% men; age 58 (46;68) years] and 182 patients with other pulmonary infections [46.9% men; age 62 (44;73) years]. The incidence of MI at ICU admission was lower in COVID-19 patients (36.4%) compared to non-COVID-19 patients (56%), and this difference persisted after adjusting for age, sex, coronary artery disease, heart failure, SOFA score, lactate, and C-reactive protein [RR 0.84 (95% CI, 0.71-0.99)]. MI at ICU admission was associated with a 59% increase in mortality [RR 1.59 (1.36-1.86); P<0.001], and there was no significant difference in the mortality between patients with COVID-19 and those with other pulmonary infections (P=0.271). Conclusion: Myocardial injury is less frequent in patients with critical COVID-19 pneumonia and respiratory failure compared to those with other types of pneumonia. The occurrence of MI is a significant risk factor for in-hospital mortality, regardless of the etiology of the pulmonary infection.