No association between SARS-CoV-2 vaccination and ischaemic stroke or high-risk transient ischaemic attack.

BACKGROUND: Initiation of SARS-CoV-2 (Severe acute respiratory syndrome coronavirus type 2) vaccinations aroused scepticism within the general-public about risks including stroke. Our aim was to explore temporal associations between vaccination and cerebrovascular events through an analysis of a prospective large-scale cohort of consecutive stroke and high-risk TIA (transitory ischaemic attack) patients.

METHODS: We prospectively recruited a cohort of consecutive ischaemic stroke and high-risk TIA (ABCD2-Score ≥ 4) patients treated at the Innsbruck University Hospital (STROKE-CARD Registry Study, NCT04582825) from December 2020 until February 2022. SARS-CoV-2 vaccination status and the time of administration was ascertained by electronic health-data. A Cox model with vaccination status as time-dependent co-variable was employed to examine its association with ischaemic events.

RESULTS: Data on 572 participants were available with 355 (62.1%) vaccinated against SARS-CoV-2 before suffering cerebral ischaemia. In our cohort, no temporal association between vaccination and cerebrovascular event was detected (HR 1.06 [0.85-1.34; p = 0.60]) and this also applies to TIA (HR [0.82 0.37-1.85; p = 0.64]) or minor stroke (HR 1.18 [0.89-1.56; p = 0.26]) and subgroups defined by sex and age. Neither vector-based (HR 1.11 [0.79-1.56; p = 0.55]) nor mRNA-based (HR 1.06 [0.84-1.34; p = 0.61]) vaccinations were associated with the occurrence of cerebral ischaemia.

CONCLUSION: Among patients with stroke or high-risk TIA, SARS-CoV-2 vaccination was not associated with cerebral ischaemia.