ABSTRACT
Background and aims: Cerebral venous sinus thrombosis with thrombocytopenia syndrome (CVST-TTS) is a rare adverse effect of adenovirus- based SARS-CoV-2 vaccines. After the autoimmune pathogenesis of TTS was discovered, treatment recommendations were issued. The aim of this study was to evaluate if adherence to treatment recommendations was associated with lower mortality. Methods: TTS was defined according to the Brighton criteria. Cases from a prospective international CVT registry with symptom onset within 28 days of adenovirus-based SARS-CoV-2 vaccination were analysed. Treatment recommendations, following the International Society of Thrombosis and Haemostasis, included use of immunomodulation, non-heparin anticoagulants, and avoidance of platelet transfusions, unless needed for surgery. Results: Out of 178 CVT cases from 117 centres in 19 countries reported between March 29 and September 3, 2021, 95 patients fulfilled inclusion criteria. Five of 37 (14%), 13/25 (52%), and 29/33 (88%) of patients diagnosed in March, April, and from May onwards, respectively, were treated according to recommendations. Proportion of patients diagnosed in March, April, and from May onwards who received immunomodulation increased from 19/37 (51%) over 15/25 (60%) to 30/33 (90%), and the percentage of patients who were treated with heparins [26/37 (70%), 4/25 (16%), 1/33 (3%)] and platelet transfusion [15/37 (41%), 4/25 (16%), 7/33 (21%), respectively] decreased accordingly. Mortality of patients treated according to recommendations was 14/47 (30%, 95%CI 19-44%) compared to 28/48 (58%, 95%CI 44-71%) in patients not treated according to recommendations (OR 3.30, 95%CI 1.41-7.71). Conclusions: Over time, adherence to treatment recommendations improved, and mortality rate of patients with CVST-TTS decreased.