Stroke Rates in COVID-19 Patients Lower Than Previously Reported

Shadi Yaghi, MD

New research from NYU Langone Health suggests the rate of stroke in US patients with coronavirus disease 2019 (COVID-19) may be lower than the 2-5% range reported in other countries.

While data from more than 3500 hospitalized patients suggested a stroke rate of less than 1%, investigators noted stroke events associated with COVID-19 appeared to be more severe.

"Our study suggests that stroke is an uncommon yet important complication of coronavirus given that these strokes are more severe when compared with strokes occurring in patients who tested negative for the virus," said lead investigator Shadi Yaghi, MD, an assistant professor in the Department of Neurology at NYU Langone Health, in a statement.

In an effort to further evaluate the rate and severity of strokes in Yaghi and a team of colleagues NYU Grossman School of Medicine designed a retrospective cohort study of consecutive patients with ischemic stroke who were hospitalized from March 15-April 19, 2020. Using data from NYU Langone hospitals in New York City and Long Island, a cohort of 3556 COVID-19-infected patients was identified for analysis.

For the purpose of the analysis, investigators compared characteristics of stroke patients with COVID-19 to stroke patients without the disease. Investigators also planned a second analysis to compare patients to a historical cohort of patients with ischemic stroke discharged from NYU Langone hospitals from March 15, 2019-April 15, 2019.

Of the 3556 COVID-19-infected patients identified, 32 (0.9%) suffered a radiologically proven ischemic stroke. Stroke was the reason for admission in 43.8% of the stroke group and COVID-19 symptoms were the reason for admission in the remaining 56.2%—indicating the index stroke occurred during the hospital stay.

Among those who suffered a stroke, the median age was 62.5 years, 23 were men, 21 were white, 6 were black, 3 were Asian, and 4 were Hispanic. Median time from first COVID-19 symptoms to identification of stroke was 10 (IQR, 5-16.5) days and the most common clinical features among these patients were cough (84.4%), fever (71.9%), and hypoxia (78.1%).

Investigators pointed out 65.6% of strokes were of cryptogenic subtype and 34.4% met criteria for an embolic stroke of undetermined source. At last follow-up, 81.3% of stroke patients met the criteria for severe disease and 75.0% were dead or critically ill.

Notable differences were observed when comparing patients with COVID-19 and stroke with the historic and contemporary cohorts.

Compared with the historic controls, patients with COVID-19 and stroke had higher inpatient mortality (63.6% vs 6.3%, P <.001), were more likely to have a cryptogenic stroke subtype (65.6% vs 25.0%, P<.001), were more likely to have proximal large vessel occlusion (45.5% vs 20.3%, P=.026), and have a higher admission National Institutes of Health Stroke Scale score (NIHSS) score (19 (23) vs 3 (12), P=.001). The COVID-19 cohort was also more likely to be men (71.9% vs 45.0%, P=.012) and more likely to have positive troponin levels (45.2% vs 8.1%, P <.001).

Compared against the contemporary cohort, patients with COVID-19 and stroke had higher inpatient mortality (63.6% vs 9.3%, P <.001), were more likely to have a cryptogenic stroke subtype (65.6% vs 30.4%, P=.003), and had higher admission NIHSS score (19 (23) vs 8 (12), P=.007). The COVID-19 cohort was also younger than stroke patients in the contemporary cohorts (63 (17) vs 70 (18), P=.001).

"Our findings provide compelling evidence that widespread blood-clotting may be an important factor that is leading to stroke in patients with COVID-19," said study investigator Jennifer Frontera, MD, a professor in the Department of Neurology at NYU Langone, in the aforementioned statement. "The results point to anticoagulant, or blood thinner therapy, as a potential means of reducing the unusual severity of strokes in people with the coronavirus."

Investigators noted further follow-up studies were planned to assess the long-term rates of stroke in COVID-19 patients as well as the impact of anticoagulant therapy.

This study, “SARS2-CoV-2 and Stroke in a New York Healthcare System,” was published in Stroke.