Clinical Characteristics, Treatment, and Outcomes of Provoked Acute Cerebral Sinovenous Thrombosis in Patients <21 Years Old: Findings from the Kids-DOTT Multinational Trial

Background

Cerebral sinus venous thrombosis (CSVT) is a rare pediatric condition with an estimated incidence of 0.7 per 100,000 children. However, amongst pediatric venous thromboembolism (VTE), the proportion of CSVT is high, at about 10% of all pediatric VTE. Key risk factors include perinatal stressors in cases of neonatal CSVT and acute infections, especially head and neck infections, in older children. To date, few multinational trials of pediatric VTE treatment have reported findings specifically among CSVT patients.

Aims

We sought to describe the clinical characteristics, treatment strategies, and outcomes of the patients with provoked acute CSVT enrolled in the Kids-DOTT trial and to compare these features to those of Kids-DOTT participants with non-CSVT VTE.

Methods

Kids-DOTT was an NIH-sponsored multinational randomized clinical trial (RCT) comparing 6 weeks vs. 3 months of anticoagulation for provoked acute VTE treatment in patients <21 years, with two non-randomized cohort arms run in parallel to the RCT for patients with persistent antiphospholipid antibodies or complete veno-occlusion at 6 weeks post-diagnosis of the index VTE. The primary RCT findings were recently published. In the present analysis, descriptive statistics were used to summarize patient and thrombus characteristics, treatments, and outcomes, and variables were compared between CSVT and non-CSVT VTE groups using Mann-Whitney U test for continuous variables and Chi-squared or Fisher's exact test, as appropriate, for categorical variables. All statistical analyses were performed using R Core Team, 2021. A P-value of <0.05 was considered statistically significant.

Results

Among 532 patients enrolled in the Kids-DOTT trial, the index VTE was a CSVT in 75 (14%). Age distribution differed significantly ( P=0.002) between CSVT and non-CSVT VTE patients, with the CSVT more likely to occur in neonates and children, compared to non-CSVT VTE more likely to occur in adolescents. CSVT was less likely to be CVC-related compared to non-CSVT VTE. The frequency of any infection (56.9% vs 26%, p<0.001) and specifically infection of the head/neck (35.4% vs 2%; P<0.001) as a provoking factor was significantly higher for CSVT vs. non-CSVT VTE. Non-head and neck infections were less likely to be associated with CSVT compared to non-CSVT VTE. One-third of CSVT patients received 6 weeks, while two-thirds received > 3 months, of anticoagulation (Table 2). No patients developed ISTH-defined symptomatic recurrent VTE or clinically relevant bleeding.

Conclusions

These multinational trial findings substantiate those of retrospective studies implicating head/neck infection as an important provoking factor for CSVT in young patients. The absence of recurrent VTE or clinically relevant bleeding among CSVT patients managed with anticoagulation in Kids-DOTT serve to augment recent RCT findings of CSVT treatment in children involving direct oral anticoagulants, demonstrating the safety and efficacy of therapeutic anticoagulation for pediatric CSVT.