High risk of pulmonary embolism in acute respiratory distress syndrome related to COVID-19: an observational controlled-cohort study

BACKGROUND: COVID-19 may induce endovascular injury of pulmonary vessels and could be associated with increased risk of pulmonary embolism. The main objective was to compare the incidence of pulmonary embolism in patients with acute respiratory distress syndrome (ARDS) related to COVID-19 versus patients with pulmonary ARDS unrelated to COVID-19. METHODS: This is an observational controlled-cohort study performed at a single center of a university teaching hospital in France. The incidence of pulmonary embolism was prospectively assessed using computed tomography pulmonary angiography (CTPA) in patients with ARDS related to COVID-19 and compared to patients from a 3-year historical cohort of patients with pulmonary ARDS unrelated to COVID-19. In patients with ARDS related to COVID-19, CTPA was performed approximately 7 days after intubation or earlier in case of respiratory or hemodynamic worsening. RESULTS: CTPA was performed in 29 out of the 42 patients (69%) with ARDS related to COVID-19 and in 51 out of the 156 patients (33%) from the historical cohort of patients with pulmonary ARDS unrelated to COVID-19. Incidence of pulmonary embolism was 40% (17/42) in patients with ARDS related to COVID-19 and 3% (5/156) in the historical cohort (P=0.001). The proportion of patients with pulmonary embolism among all patients who had CTPA was 59% (17/29) in patients with ARDS related to COVID-19 and 10% (5/51) in the historical cohort (P=0.0001). After adjustment on the interval between ICU admission and computed tomography, COVID-19 remained independently associated with pulmonary embolism. CONCLUSIONS: Pulmonary embolism was particularly frequent in patients with ARDS related to COVID-19, thereby suggesting that CTPA should be systematically performed in these patients.