Incidence of thrombotic complications in COVID-19 : On behalf of ICODE: The International COVID-19 Thrombosis Biomarkers Colloquium

Abstract

A high incidence of thrombosis in hospitalised patients with COVID-19 was identified early during the pandemic. Accurately quantifying thrombotic risk may assist prognosis and guide appropriate thromboprophylaxis. Observational studies have estimated the rate of thrombosis in both hospitalised and non-hospitalised patients with COVID-19, and how this corresponds to the severity of illness. In this review, we provide an overview of the incidence and prevalence of arterial and venous thrombotic events in patients with COVID-19 and highlight the limitations in the studies to date. Asymptomatic individuals with COVID-19 and those with mild symptoms are at very low risk of thrombotic complications. However, rates of thrombosis are substantially increased in hospitalised patients, and are strikingly high in those patients who are critically-ill requiring treatment on the intensive care unit and especially those requiring extracorporeal membrane oxygenation. Clinicians managing such patients need to be aware of these risks and take appropriate steps with respect to thromboprophylaxis and heightened clinical vigilance. Large prospective observational studies will more accurately quantify thrombotic rate, and randomized controlled trials are currently investigating optimal thromboprophylactic strategies.

Keywords: Arterial thrombosis; COVID-19; Deep venous thrombosis; Thromboembolism; Thrombosis.

Fig. 1

Incidence of thrombotic complications in patients with COVID-19, from selection of described papers

Fig. 2

Thoracic imaging of patient with COVID-19 pneumonia with associated pulmonary emboli. Patient managed for COVID-19 pneumonia and pulmonary emboli. Images courtesy of Radiology Department, East and North Hertfordshire NHS Trust. a Chest X-ray showing bilateral peripheral consolidation with mid and lower zone predominance, compatible with COVID-19 pneumonia. b CTPA lung window showing organising pneumonia pattern typical of COVID-19 pneumonia with peripheral consolidation in a perilobular pattern. c CTPA mediastinal window showing large pulmonary embolism within distal right main pulmonary artery (yellow arrow) and small left upper lobe pulmonary embolism (white arrow)