Optimal Management of Thrombotic Complications in Patients With Coronavirus Disease 2019.

To the Editor:

Coronavirus disease 2019 is associated with coagulopathy (1). We read with interest the study of Mirsadraee et al (2) published in the recent issue of Critical Care Medicine, who demonstrated that thrombotic complications are frequently observed in critically ill patients with severe coronavirus disease 2019 hospitalized in the ICU by performing routine image surveillances. Several concerns have been raised.

The authors could not find any baseline characteristics including coagulopathy-related biomarkers that predicted thrombotic complications (2). In their definition, all thrombotic complications were counted as end points. How about investigating factors associating with severe or fatal thrombotic complications, instead of all thrombotic complications? They should be the end point that we want to predict.

In their study, the patients with thrombotic complications had a higher prevalence of mortality (2). The next concern is causality: whether the thrombotic complications themselves were directly associated with death or the severity of coronavirus disease 2019 and comorbidities were associated with death (1). Causes of death and multivariate analyses adjusting for baseline characteristics would approach this concern. Several patients seem to have received repeated image assessments (2). Additional analyses to investigate the prognostic impact of improvement in thrombotic complications would clarify the implication of aggressive intervention to the thrombotic complications.