Imaging data
Prior to acetazolamide administration, the mean whole-cortex CBF did not differ significantly between never-infected and previously infected participants. However, following the acetazolamide administration, the mean whole-cortex CBF was greater in never-infected participants (73.8 mL/100 g/min vs. 60.5 mL/100 g/min, respectively; P = .04).
Moreover, the mean whole-brain CVR was greater in never-infected participants, compared with previously infected participants (27.8 mL/100 g/min vs. 19.1 mL/100 g/min; P < .001).
After adjusting for age and sex, researchers found that prior infection was associated with a lower whole-brain CVR (–8.9 mL/100 g/min; 95% confidence interval, 4.6-13.3 ml/100g/min; P < .001).
Previously infected individuals also showed significantly lower CVR, even after the researchers excluded those with prior critical illness.
A nonsignificant difference was found in previously infected participants, with smaller CVR in participants with versus without post-COVID neurologic symptoms (16.9 vs. 21.0 mL/100 g/min; P = .22).
In addition, 40% of the previously infected participants versus 10% of the never-infected participants had at least one vessel wall imaging abnormality – but the difference was not deemed significant (P = .18). Notably, “all detected vessel wall imaging abnormalities were morphologically consistent with atherosclerosis rather than vasculitis,” the investigators said.
Dr. Callen said it is “unknown whether the lack of statistical significance in the differences in vasoreactivity impairment with those living with long COVID symptoms is due to a lack of a biomechanistic correlation or due to statistical underpowering.”
If it is the latter, “it may emphasize the role of vascular health in those living with long COVID symptoms and potentially all individuals living with COVID,” he added.
Independent risk factor?
Commenting on the study for this article, Jared Narvid, MD, associate professor of neuroradiology, University of California, San Francisco, said it “adds to the literature suggesting a correlation between COVID-19 infection and measures of cerebrovascular abnormality.”
Dr. Narvid, who was not involved with the research, added that “although it is a small case-control study, it is well executed and should encourage scientists to further study whether COVID-19 infection represents an independent risk factor for cerebrovascular disease.”
The investigators agree. “Future studies are needed to determine the clinical implications arising from SARS-CoV-2–associated CVR impairment,” they write.
The study was funded by a University of Colorado department of radiology Faculty Development Seed Grant. The investigators and Dr. Narvid report no relevant financial relationships.
A version of this article first appeared on Medscape.com .