PB0623 - A comprehensive review of low-molecular-weight-heparin anticoagulation therapy dose management in pediatric patients at risk of thrombocytopenia

Background: Due to their disease and treatments, pediatric patients with cancer have increased risks of thromboembolism (TE) and thrombocytopenia. There is paucity of evidence assessing the management of anticoagulation therapies (ACT) for pediatric patients with concurrent thrombocytopenia.

Aims: This comprehensive review aims to summarise and evaluate the evidence on the safety and efficacy of low-molecular-weight-heparin (LMWH), the most common ACT for children, in pediatric patients with concurrent thrombocytopenia.

Methods: A literature search was conducted on MedLine and backward snowball sampling was employed. All available studies published in English assessing LMWH-ACT safety and efficacy as a therapeutic or prophylactic intervention in children up to 18 years old at risk of thrombocytopenia were included. Safety and efficacy were assessed through the rate of bleeding episodes and thrombosis outcomes, respectively.

Results: Of 13 included studies, most were retrospective-cohorts (53.8%) and prospective-cohorts (30.8%). The age of participants across the studies ranged from 3 weeks to 18 years old. LMWH-ACT dose adjustments were unspecified in 3 studies. Amongst those that specified adjustments, 3 held LMWH when platelets were below 20x109/L and 1 held LMWH when below 50x109/L. From those withholding LMWH below 20x109/L, 2 administered half-dose LMWH when platelets were between 20x109/L-30x109/L. In 8 studies, platelets were transfused during LMWH-ACT (1 maintained platelets > 50x109/L, 2 > 30x109/L, and 3 > 10x109/L-20x109/L). No ACT-associated bleeds were reported in 8 studies (61.5%), and 5 studies (38.5%) reported at least one bleed (4/13 major, 8/13 minor, 1/13 unspecified). The average rate of complete/partial resolution was 86.9%, stable/progressed thrombus response was 9.0%, and 4.1% was associated with indeterminate data.

Conclusion(s): Dose-adjusted LMWH-ACT seems safe and effective for pediatric patients with concurrent thrombocytopenia. However, there is heterogeneity of LMWH-ACT management in the context of thrombocytopenia. Studies with greater sample sizes and randomised studies are needed to provide greater evidence on LMWH-ACT for this population.