European Collaborative Paediatric Database on Cerebral Venous Thrombosis: Risk Factors for Recurrent Venous Thromboembolism.

Background: Risk factors for cerebral venous thrombosis (CVT) in children include local and systemic underlying conditions, drug toxicity, and hereditary prothrombotic risk factors. Their relevance to the risk of a second venous thrombosis (VT), compared with other clinical, neuroimaging and treatment variables, is unknown.

Methods: 330 of 407 consecutively enrolled CVT-patients aged newborn to <18 years (median 5.3 years; male 55%) were prospectively followed for a median (range) of 33 (12–84) months. In accordance to international treatment guidelines, 259 children (78.5%) received acute antithrombotic therapy (AT) with UFH or LMWH, followed by long-term AT with LMWH or warfarin in 218 cases (66.0%).

Findings: Recurrent VT was diagnosed in 19 of 330 children (5.8%) at a median (range) age of 6 (0.5–84) months following CVT, with no difference observed between the study centres (p=0.84). Multivariate Cox regression analysis revealed that the risk of recurrence was significantly higher in those with older age at first CVT onset (p=0.02), those in whom AT was not administered prior to recurrence (p=0.0003), those who did not have complete patency rates on repeat venography at 3–6 months (p=0.01), and those subjects carrying the factor II G20210A mutation (p=0.03).

Interpretation: Age at CVT onset, administration of AT, poor patency rates, and the factor II G20210A variant were of relevance to recurrent VT in children with CVT. Until evidence-based data derived from randomized treatment trials are available the message of this follow-up study is to administer any AT prophylaxis on an individual patient basis in paediatric CVT cases in newly identified VT risk situations.