By Matthew E. Fink, MD

Louis and Gertrude Feil Professor and Chair, Department of Neurology, Associate Dean for Clinical Affairs, NYP/Weill Cornell Medical College

Dr. Fink reports no financial relationships relevant to this field of study.

SOURCE: Merkler AE, Parikh NS, Mir S, et al. Risk of ischemic stroke in patients with coronavirus disease 2019 (COVID–19) vs patients with influenza. JAMA Neurol 2020; July 2. doi:10.1001/jamaneurol.2020.2730. [Online ahead of print].

Early in the COVID-19 pandemic, reports emerged from China and France that there might be an increased risk of ischemic stroke. Many patients developed a hypercoagulable state with thrombotic complications in multiple organs, including the lungs, kidneys, heart, liver, and brain. During the surge in COVID-19 infections in New York City, many neurologists observed an unusual frequency of ischemic stroke.

Merkler and colleagues designed a retrospective cohort study of patients admitted with COVID-19 infection, confirmed by polymerase chain reaction testing by a nasal swab, from March 4, 2020, through May 2, 2020. They identified all acute strokes, and compared them with a matched group of patients hospitalized with influenza A and B from January 2016 through May 2018. It is well documented that influenza epidemics are associated with a higher risk of ischemic stroke and myocardial infarction, as are all systemic inflammatory disorders. Merkler and colleagues wanted to determine if coronavirus infection induced a higher risk of ischemic stroke than other viral infections, such as influenza.

A total of 1,916 patients with documented COVID-19 infection were admitted to the hospital, and 31 suffered an acute ischemic stroke during their hospitalization (95% confidence interval [CI], 1.1%-2.3%). The median age was 69 years, and 58% were men. Eight patients presented to the hospital with stroke as their chief complaint.

Of 1,486 patients with influenza, only three suffered an acute ischemic stroke during hospitalization (95% CI, 0.0%-0.6%). After adjustment for demographic factors, age, sex, and race, the probability of stroke was higher with COVID-19 infection than with influenza infection (odds ratio, 7.6; 95% CI, 2.3-25.2). This high rate of ischemic stroke is consistent with reports from other centers in New York City, as well as in cities around the world that have reported their findings.

The observed thrombotic events likely are the cause for the high rate of ischemic stroke in these patients and should be addressed aggressively as part of a comprehensive treatment plan. Right now, it is unknown what the long-term consequences will be in this population. Regardless, it is likely there will be a high rate of physical disabilities and neurological disabilities.