Vaccination against COVID-19 and Outcomes in Patients with COVID-19 Infection and Stroke

We aimed to determine the clinical impact of prior vaccination against Coronavirus Disease 2019 (COVID-19) on COVID-19 infection associated acute ischemic stroke (AIS). Using the TriNetX COVID-19 Research Network, an international electronic health record database, we identified AIS cases admitted between April 1, 2021 and September 30, 2022 that had a COVID-19 diagnosis up to 30 days before hospitalization. The study cohort was divided into two groups: those with and without vaccination against COVID-19. The two groups were matched for demographics, comorbidities, and antithrombotics taken before AIS with 1:1 propensity score matching. Cox proportional hazard analysis was performed to report primary (all-cause mortality) and secondary outcomes at 7 and 30 days after AIS. We identified 3,573 vaccinated (71 ± 12 (mean ± SD) years, 49% females) and 46,329 unvaccinated patients (65 ± 15 years, 45% females) who met the study criteria. After propensity score matching, 3,569 patients were in both groups. Vaccinated individuals had significantly lower rates of all-cause mortality [7 days: 3.3% vs 5.0%; HR = 0.66; 95% CI = 0.52-0.83 and 30 days: 8.2% vs 9.5%; HR = 0.83; 95% CI = 0.71-0.97], intracranial hemorrhage [7 days: 4.1% vs 6.2%; HR = 0.66; 95% CI = 0.53-0.82 and 30 days: 4.5% vs 6.7%; HR = 0.66; 95%CI = 0.53-0.81], venous thromboembolism [7 days: 3.5% vs 7.8%; HR = 0.44; 95% CI = 0.35-0.56 and 30-days: 4.6% vs 8.9%; HR = 0.51; 95% CI = 0.41-0.63] and acute myocardial infarction [7 days: 4.1% vs 7.0%; HR = 0.58; 95% CI = 0.46-0.73 and 30 days: 4.7% vs 7.6%; HR = 0.60; 95% CI = 0.49-0.75)]. Prior vaccination against COVID-19 is associated with reduced rates of all-cause mortality, intracranial hemorrhage, venous thromboembolism, and acute myocardial infarction within 30 days of COVID-19 associated AIS.