Arterial floating mural thrombi are a characteristic imaging pattern in SARS-CoV-2- related ischemic stroke

Background Acute ischemic stroke (AIS) is a complication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We aimed to explore neurovascular imaging patterns in patients with SARS-CoV-2-related AIS. Methods We retrospectively analyzed clinical and radiological data of patients hospitalized with AIS and a positive PCR test for SARS-CoV-2 prior to AIS onset. The control group comprised of AIS patients from a pre-COVID-19 pandemic period matched for gender and age. Results Thirty-five SARS-CoV-2-related stroke patients, and 35 controls were included. Fiftyseven percent of SARS-CoV-2 patients had either mild or asymptomatic disease. A distinctive imaging pattern of floating arterial mural thrombus was detected in 5 patients of the SARS-CoV-2 group. In 4 patients thrombus was attached to a stenotic atherosclerotic plaque in the proximal internal carotid artery. In the 5th patient a cardiac CTA showed multiple floating thrombi in the descending aorta. In the control group, floating thrombus was only detected in one patient. Treatment with dual antiplatelet therapy was associated with thrombus dissolution and good clinical outcome. Patients with floating thrombi had a longer time from SARS-CoV-2 diagnosis to stroke onset (mean 7.4 versus 3.4 days). Conclusions Floating arterial mural thrombi attached to atherosclerotic plaques are unique characteristic source of AIS in SARS-CoV-2 patients. They may lead to ischemic stroke in patients with mild or asymptomatic infection up to 1-2 weeks from SARS-CoV-2 diagnosis. Patients with embolic AIS and SARS-CoV-2 diagnosis should perform high resolution cranio-cervical vascular imaging to evaluate floating thrombi as a potential embolic source.