The new coronavirus disease (SARS-CoV-2) has caused more than 350,000 deaths worldwide. Thrombotic complications due to considerable inflammation, cytokine-mediated microvascular damage and pulmonary immunothrombosis formation seem to have emerged as an important issue in people infected with COVID-19.
This study reviewed consecutive symptomatic patients with proven COVID-19 infection admitted to Acibadem University Hospital in Istanbul, Turkey (15 March-25 May 2020). The primary outcome was any venous thromboembolic (VTE) complication. The secondary outcome was the incidence of subsegmental pulmonary embolism with or without deep vein thrombosis (DVT), which represented immunothrombosis development.
The mean age was 55.7±17.4 years (range, 29-84); 224 (63.6%) were men. Of those patients, 12 (3.4%) died, 273 (77.5%) were discharged alive and 67 (19.1%) were still hospitalised as of 25 May 2020. Venous thromboembolic events occurred in 58 patients with a cumulative rate of 16.4% during the study period. The surprising discovery was that DVT was not identified in 20 (86.9%) of the 23 patients with subsegmental pulmonary embolism, which corroborated the pulmonary immunothrombosis theory.
The high incidence of VTE events suggests an important role of COVID-19-induced coagulopathy. Thus, repeated assessment and optimised treatment are necessary to reduce the occurrence of VTE and prevent fatal pulmonary embolism events. Further studies are needed to investigate the molecular mechanism of this immunothrombosis development.

Copyright © 2020 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.