While initial reports suggested a significant risk of stroke in patients hospitalized with Covid-19, now a new study shows a low risk of stroke in patients hospitalized for coronavirus. According to the study, published in the journal Stroke from Penn Medicine, the majority of afflicted patients had existing risk factors, such as high blood pressure and diabetes.
"While there was an initial concern for a high number of strokes related to COVID-19, that has not been born out," said study senior author Brett Cucchiara from the University of Pennsylvania in the US. To evaluate the risk and incidence of stroke in COVID-19 hospitalized patients, researchers analyzed data from 844 COVID-19 patients admitted to the hospital between March and May.
Cerebrovascular Events Associated With Existing Conditions
The team also analyzed the data for cases of intracranial hemorrhage (bleeding in the brain). Researchers found that 2.4 percent of patients hospitalized for COVID-19 had an ischemic stroke -- the most common type of stroke, typically caused by a blood clot in the brain. Importantly, the majority of these stroke patients had existing risk factors, such as high blood pressure (95 percent) and a history of diabetes (60 per cent), and traditional stroke mechanisms, such as heart failure.
Additionally, over one-third had a history of a previous stroke. Researchers say the results suggest that these cerebrovascular events in hospitalized COVID-19 patients are likely tied to existing conditions, and not the sole consequence of the virus.
Inflammation and Blood Clotting
However, other factors could be at play and require continued research. While the precise mechanisms linking cerebrovascular events to COVID-19 remain uncertain at this time, it has recently been reported that the viral infection, SARS-CoV-2, causes inflammation and a hypercoagulable state (excessive blood clotting) -- both could be potential mechanisms leading to stroke.
In addition to the incidents of stroke, the research team found that 0.9 percent of hospitalized COVID-19 patients had intracranial hemorrhage. While the rate of stroke in hospitalized COVID-19 patients is comparable to studies in Wuhan, China and Italy, the rate of intracranial hemorrhage, which has not previously been reported, is higher than investigators expected. The authors noted this could be tied to the increasing use of anticoagulant therapy (blood thinners) in COVID-19 patients, and requires additional exploration.