Vascular Thrombosis in Severe COVID-19 Requiring Extracorporeal Membrane Oxygenation

A Multicenter Study

Jonathan R. Weir-McCall, PhD; Gabriel Galea, MBChB; Sze Mun Mak, MBChB; Kushal Joshi, MBChB; Bobby Agrawal, MBChB; Nicholas Screaton, MBChB; Mark Toshner, MD; Alessandro Ruggiero, PhD; Giulia Benedetti, MBChB; Jan Brozik, MBChB; Ruth Machin, MBChB; Indrajeet Das, MBChB; Marusa Kotnik, MBChB; Julia Sun, MBChB; Michael Mackay, MBBChir; Joseph Jacob, MD; Jonathan C. L. Rodrigues, MD; Luigi Camporota, PhD; Alain Vuylsteke, MD


Crit Care Med. 2022;50(4):624-632. 

In This Article

Abstract and Introduction


Objectives: Coronavirus disease 2019 has been reported to be a prothrombotic condition; however, multicenter data comparing this with other viral pneumonias in those requiring extracorporeal membrane oxygenation are lacking. We conducted a multicenter study using whole-body CT to examine the prevalence, severity, and nature of vascular complications in coronavirus disease 2019 in comparison with patients with other viral pneumonias.

Design: We analyzed whole-body CT scans for the presence of vascular thrombosis (defined as pulmonary artery thrombus, venous thrombus, systemic arterial thrombus, or end-organ infarct). The severity, distribution, and morphology of pulmonary artery thrombus were characterized. Competing risk cumulative incidence analysis was used to compare survival with discharge.

Setting: Three centers of the English national extracorporeal membrane oxygenation service.

Patients: Consecutive patients admitted with either coronavirus disease 2019 or noncoronavirus disease 2019 viral pneumonia admitted from January 2019.

Interventions: None.

Measurements and Main Results: One-hundred thirty-six patients (45.2 ± 10.6 yr old, 39/146 [27%] female) requiring extracorporeal membrane oxygenation support underwent whole-body CT scans at admission. Of these, 86 had coronavirus disease 2019 pneumonia, and 50 had noncoronavirus disease 2019 viral pneumonia. Vascular thrombosis was seen more often in patients with coronavirus disease 2019 (odds ratio, 12.9 [95% CI 4.5–36.8]). In those with coronavirus disease 2019, 57 (73%) demonstrated pulmonary artery thrombus or pulmonary perfusion defects. Eighty-two percent of thrombus exhibited emboli-like morphology. The location of pulmonary artery thrombus and parenchymal perfusion defects was only concordant in 30% of cases. The risk of mortality was higher in those with coronavirus disease 2019 compared with noncoronavirus disease 2019 pneumonia (χ 2 = 3.94; p = 0.047). Mortality was no different in coronavirus disease 2019 patients with or without vascular thrombosis (χ 2 = 0.44; p = 0.51).

Conclusions: In patients who received extracorporeal membrane oxygenation, coronavirus disease 2019 is associated with a higher prevalence of vascular thrombosis compared with noncoronavirus disease viral pneumonias. The pattern of pulmonary vascular changes suggests concurrent embolic disease and small vessel disease. Despite this, vascular thrombosis was not linked to poorer short-term prognosis in those with coronavirus disease 2019.


A high prevalence of vascular thrombosis has been reported in coronavirus disease 2019 (COVID-19), with this associated with an elevated risk of mortality.[1] The prevalence of thrombus in COVID-19 varies with disease severity, reported in 5% of non-ICU cohorts and 31% of ICU cohorts in a recent meta-analysis.[1]

However, other viral pneumonias have been reported to also exhibit high rates of thromboembolic events.[2] Critically ill patients are generally predisposed to coagulopathy and thromboembolism due to a combination of systemic inflammation, platelet activation, endothelial dysfunction, and stasis of blood flow.[3] Evidence that the prevalence or severity of vascular thrombosis is different from other viral pneumonias is limited.[4] It is also not clear whether the high reported rates of pulmonary artery thrombus (PAT) is thromboembolic or an in situ thrombosis due to a combination of severe local inflammatory changes and microvascular angiopathy.[5]

Identification of the true prevalence and risk of COVID-19 for vascular thrombosis as well as its nature is important as it may guide treatment, either in the use of current anti-thrombotic drugs or development of new treatments targeting a virus-specific causative pathway.[6]

We conducted a multicenter study using whole-body CT to examine the prevalence, severity, and nature of vascular complications in severe COVID-19 in comparison with patients with other viral pneumonias.