ABSTRACT
Background and aims: Cerebral venous sinus thrombosis (CVST) has been acknowledged as a rare adverse event related to thrombosisthrombocytopenia syndrome (TTS) following COVID-19 vaccination. Methods: A systematic review and meta-analysis of investigator-initiated registries including confirmed CVST cases was performed, with the aim to calculate the odds ratio of TTS-CVST versus non-TTS-CVST (1) after vector-based vaccines and (2) after non-vector-based vaccines;(3) the inhospital mortality ratio of TTS-CVST compared to non-TTS-CVST;and (4) the dependency or death at discharge among TTS-CVST compared to non-TTS-CVST cases. Results: Two eligible studies were included in the meta-analysis, comprising a total of 211 patients with CVST associated with COVID-19 vaccination. Vector-based COVID-19 vaccination was associated with a higher likelihood of TTS-associated CVST than with non-TTS-CVST (OR: 52.34, 95%CI: 9.58-285.98). TTS-CVST was also associated with higher likelihood of in-hospital mortality (OR: 13.29;95%CI: 3.96-44.60) and death or dependency at discharge compared to non-TTS-CVST (OR: 6.70;95%CI: 3.15-14.26). TTS-CVST was recorded with a shorter interval between vaccination and symptom onset [Mean Difference (MD):- 6.54 days;95%CI:-12.64 - -0.45], affecting younger patients (MD:-9.00 years;95%CI: -14.02 - -3.99) without risk factors for thromboses (OR:2.34;95%CI: 1.26-4.33), and was complicated more frequently with intracerebral hemorrhage (OR:3.60;95%CI: 1.31-9.87) and concomitant thromboses in other sites (OR:11.85;95%CI: 3.51-39.98) compared to non-TTS-CVST cases. Conclusions: TTS-CVT following COVID-19 has distinct clinical phenotype and prognosis compared to non-TTS-CVT. Further epidemiological data are required to evaluate the impact of different treatment strategies on outcome of TTS-CVT cases following COVID-19 vaccination.