No Differences in CVT Volume, Mortality During First Year of the COVID-19 Pandemic Compared to Prior Year

Despite recent studies that have suggested an increased incidence of blood clots in the veins of the brain, called cerebral venous thrombosis (CVT), during the COVID-19 pandemic, a new international study has found no increase in CVT hospitalization volume or death compared to the year preceding the pandemic.

“During the first year of the pandemic, there was no increase in CVT hospitalization volume compared to the year preceding the pandemic. This is new because there have been several reports during the first wave of the pandemic describing a suspected rise in the incidence of CVT with the COVID-19 pandemic,” said co-corresponding author Thanh Nguyen, MD, professor of neurology, neurosurgery and radiology at BUSM and director of the neuroendovascular service at Boston Medical Center.

Led by researchers from BUSM and the University of Pittsburgh Medical Center (UPMC), this cross-sectional study included 171 stroke centers from 49 countries. Monthly COVID-19 admission volumes, CVT hospitalization and CVT in-hospital mortality from January 2019 to May 2021 were recorded. The metrics during the first year of the pandemic were then compared to the year preceding the pandemic.

Although they found no increase in CVT in-hospital mortality in the first year of the pandemic compared to the prior year, they did see an increase in in-hospital mortality among patients who had CVT along with COVID-19, compared to patients who had CVT with no COVID-19. “While we were not able to dive into the cause of mortality for these patients, it suggests that similar to other neurovascular conditions such as ischemic stroke, patients who are free from COVID-19 do better than those who contract an infection with COVID-19,” explained Nguyen.

According to the researchers, this study reinforces the importance of the public to get their COVID-19 vaccinations to reduce the potential severity of illness in the rare event of co-occurrence with other neurovascular disease.

“Vaccines are important tools in our medical toolkits that prevent severe illness and death from COVID-19,” said co-author Raul Nogueira, MD, professor neurology and neurosurgery at the University of Pittsburgh and director of the UPMC Stroke Institute. “Our analysis suggest that the benefit of vaccines clearly outweighs their risks in preventing mortality from COVID-19 related CVT.”

These findings appear online in the Journal of Stroke.