Cerebral Venous Thrombosis after ChAdOx1 nCoV-19 vaccination: a systematic review

OBJECTIVE: To perform a systematic review of case reports or case series regarding thrombosis with thrombocytopenia syndrome (TTS) and cerebral venous thrombosis (CVT) related to ChAdOx1 nCoV-19 vaccination to address the clinical features, laboratory findings, treatment modalities, and prognosis related with CVT. SUBJECTS AND METHODS: We included 64 TTS patients from 19 articles, 6 case series and 13 case reports, in which thrombosis occurred after the first dose of ChAdOx1 nCoV-19 vaccination published up to 30 June 2021 in Embase, ePubs, Medline/PubMed, Scopus, and Web of Science databases. RESULTS: Of the 64 TTS patients, 38 (59.3%) had CVT. Patients with CVT were younger (median 36.5 vs. 52.5 years, p<0.001), had lower fibrinogen levels (130 vs. 245 mg/dL, p=0.008), had more frequent history of intracerebral hemorrhage (ICH), and had higher mortality rate (48.6% vs. 19.2%, p=0.020) than that of patients without CVT. In multivariable analysis, the possibility of presence of CVT was higher in younger age groups [odd ratio (OR): 0.91, 95% confidence interval (CI): (0.86-0.97, p<0.001)] and those with accompanying intracerebral hemorrhage (ICH) (OR: 13.60, 95% CI (1.28-144.12, p=0.045). CONCLUSIONS: Our study demonstrated that CVT related to ChAdOx1 nCoV-19 vaccination was associated with younger age, low levels of fibrinogen, presence of ICH and more frequent mortality compared to those of non-CVT. If TTS occurs after ChAdOx1 nCoV-19 vaccination, the presence of CVT in patients with young age or ICH should be considered.