Thrombotic events and prophylactic anticoagulation in pediatric patients with COVID-19: a systematic review and meta-analysis.
Venous thromboembolism (VTE) can occur in children with COVID-19, and the efficacy and safety of prophylactic anticoagulant therapy are uncertain. This study aimed to assess the incidence of VTE in pediatric patients with COVID-19, the association of D-dimer with thrombus formation, and the effectiveness and safety of prophylactic anticoagulation treatment. We systematically searched databases from January 2020 to February 2023. A systematic review and meta-analysis were conducted to determine the incidence of VTE in children and evaluate the efficacy and safety of prophylactic anticoagulant therapy. Thirteen cohort studies and one clinical trial were included. The pooled incidence rate of VTE in affected children was 1.5% (95% CI 0.4-2.9%). Children with D-dimer levels five times higher than normal had a higher risk of VTE (OR 4.92, 95% CI 1.60-15.11). Prophylactic anticoagulant therapy did not significantly reduce the risk of VTE (OR 1.35, 95% CI 0.74-2.49). The safety of prophylactic anticoagulant therapy was relatively high, with major bleeding and all-cause mortality rates below 0.1% (95% CI 0.0-0.2%). The incidence of VTE in children with COVID-19 is low, and prophylaxis based on ISTH standards is reasonable. Low-molecular-weight heparin (LMWH) for VTE prevention has a high level of safety. However, more high-quality studies are needed to understand the impact of anticoagulant therapy on VTE incidence in pediatric patients with COVID-19.