The objective of this retrospective cohort study was to compare the rate of ischaemic stroke between patients with COVID-19 and patients with influenza, a respiratory viral illness previously associated with stroke.
The study was conducted at 2 academic hospitals in New York City and included adult patients with emergency department visits or hospitalisations with COVID-19 from March 4, 2020 through May 2, 2020. The comparison cohort included adults with emergency department visits or hospitalisations with influenza A or B from January 1, 2016 through May 31, 2018. Among 1916 patients with emergency department visits or hospitalisations with COVID-19, 31 (1.6%; 95% CI 1.1%-2.3%) had an acute ischaemic stroke. The median age of patients with stroke was 69 years (interquartile range 66-78 years); 18 (58%) were men. Stroke was the reason for hospital presentation in 8 cases (26%). In comparison, 3 of 1486 patients with influenza (0.2%; 95% CI, 0.0%-0.6%) had an acute ischaemic stroke. After adjustment for age, sex, and race, the likelihood of stroke was higher with COVID-19 infection than with influenza infection (odds ratio 7.6; 95% CI, 2.3-25.2). The association persisted across sensitivity analyses adjusting for vascular risk factors, viral symptomatology, and intensive care unit admission. In this retrospective cohort study from 2 New York City academic hospitals, approximately 1.6% of adults with COVID-19 who visited the emergency department or were hospitalised experienced ischaemic stroke, a higher rate of stroke compared with a cohort of patients with influenza. The authors underline that additional studies are needed to confirm these findings and to investigate possible thrombotic mechanisms associated with COVID-19.