The association between previous SARS-CoV-2 infection and incidence of stroke

Objectives: To define the association between prior SARS-CoV-2 infection and incidence of stroke. Methods: We conducted a case-control study combining the Qatar stroke database and the Qatar National COVID-19 databases. Cases with stroke diagnosis were matched 1:1 on demographics, comorbidities, and vaccination status to controls who tested negative for SARS-CoV-2 during the same week. Adjusted odds ratios (aORs) comparing the odds of previous documented SARS-CoV-2 infection in cases relative to controls were estimated using conditional logistic regression. Results: Among 1640 matched pairs, 234 (14.3%) previous SARS-CoV-2 infections were recorded among cases and 399 (24.3%) among controls. The aOR (95% confidence interval [CI]) for the association of previous infection with stroke was 0.48 (0.40-0.58). Subgroup analyses revealed aORs of comparable magnitude among those aged 40-59 years and ≥60 years and those with or without coexisting conditions. Those unvaccinated (aOR 0.43; 95% CI 0.29-0.62), vaccinated with two doses (aOR 0.46; 95% CI 0.35-0.60), and vaccinated with three or more doses (aOR 0.63; 95% CI 0.42-0.96) all exhibited similar protective association of previous infection with stroke. Conclusions: Individuals with previous COVID-19 infection are less likely to develop stroke; this finding is not explained by demographic characteristics, comorbidities, or previous vaccination status.