Vascular Thrombosis in Severe COVID 19: A Multicenter Study

BACKGROUND: COVID-19 has been reported to be a prothrombotic condition. We aimed to compare the prevalence of vascular thrombosis in patients with either severe COVID-19 or non-COVID-19 viral pneumonia. METHODS: We analysed whole-body CT scanners obtained in consecutive patients admitted in three centers of the English national ECMO service. We included consecutive patients with either COVID-19 or non-COVID-19 viral pneumonia admitted from January 2019. The presence of vascular thrombosis (defined as pulmonary artery thrombus, venous thrombus, systemic arterial thrombus, or end organ infarct) and hemorrhage was recorded. Clinical outcomes were examined using a 7-point ordinal scale. RESULTS: 136 patients (45.2±10.6 years of age, 39/146 (27%) female) requiring ECMO support underwent whole-body CT scanner on admission. Of these 86 had COVID-19 pneumonia, and 50 had non-COVID-19 viral pneumonia. Vascular thrombosis was seen more often in patients with COVID-19 (OR 12.9 (95% CI 4.5;36.8)). There was no difference between the groups in the prevalence of hemorrhage (OR 2.1 (95%CI 0.6;7.2)). The risk of mortality was 1.8 (95%CI 0.97;3.44, p=0.06) in those with COVID-19 compared with non-COVID-19 pneumonia. Mortality was no different in COVID-19 patients with or without vascular thrombosis (HR 1.03 (95% CI 0.38;2.76, p=0.96) but was higher in those patients with hemorrhage on admission (HR 3.0 (95% CI 1.06;8.5, p=0.038)). CONCLUSION: COVID-19 is associated with a significantly higher prevalence of vascular thrombosis compared with non-COVID-19 viral pneumonias. Despite this, vascular thrombosis was not linked to poorer short-term prognosis in those with COVID-19.FUNDING STATEMENT: No funding to declare.DECLARATION OF INTERESTS: The authors have no conflict of interest to declare.ETHICS APPROVAL STATEMENT: The study was approved by the institutional review boards of the 3 centers with a waiver for consent due to the observational nature of the study.