A Retrospective Multicenter Study of Arterial Thromboembolic Events in Hospitalized COVID-19 Patients: Incidence and Imaging Characteristics.

Objectives: Throughout the pandemic, it has become evident that COVID-19 should be recognized as a systemic disease that can affect the coagulation system, potentially resulting in arterial thrombotic events (ATE) with partially bulky free-floating clots. This study aimed to investigate the incidence and imaging characteristics of ATE in hospitalized patients with COVID-19 using clinical and imaging data.

Methods: From January 2020 to May 2021, databases of five German tertiary care centers were retrospectively screened for COVID-19 patients with coincidental ATE. ATE were analyzed for localization, time of occurrence, imaging characteristics, and associations with clinical data and laboratory parameters.

Results: Out of 3267 patients, 110 ATE (102 patients, mean age, 72.01 ± 15.64 years; 63 men) were observed in the presence of COVID-19 (3.1%). ATE included ischemic stroke (40%), myocardial infarction (46.4%, %), peripheral infarction (3.6%), thrombi in precerebral arteries (3.6%), mesenteric ischemia (2.7%), thrombi in the aorta (1.8%), splenic infarction (0.9%), and kidney infarction (0.9%). The median time interval between the onset of typical respiratory COVID-19 symptoms and ATE was four days (range, -5-58, negative values indicate ATE prior to symptom onset). A significant percentage of patients exhibited ATEs with an atypical free-floating appearance (10.0%) and multiple occlusions (21.2%).

Conclusion: COVID-19 is a systemic disease associated with ATE in all vascular regions, with a predilection for the heart and brain. The incidence of ATE might be higher than in comparable viral infections and ATE possibly exhibit distinct imaging features rarely seen, such as bulky free-floating clot masses and multiple occlusions. ATE occur most frequently during the first week around the COVID-19 diagnosis.