Abstract Number: PB0792
Meeting: ISTH 2021 Congress
Background: We have previously reported (Fedorova DV et al., ISTH2019 PB 0852; PB 0853; Morozova DS et al., ISTH2019, PB 0856) frequency analysis of VTE incidence in hospitalized children with different blood disorders, which has several limitations. To improve the quality of research, here we report cumulative incidence rates (CIR) of VTE, asymptomatic or incidental (aVTE) and symptomatic (sVTE) in this cohort of patients.
Aims: to analyze incidence of VTE in hospitalized children with different blood disorers.
Methods: Data of 533 VTE cases in 1962 hospitalized children aged 0-17 years with objectively confirmed diagnosis of ALL, AML, lymphoma, histiocytosis (Hc) and aplastic anemia (AA) was retrospectively analyzed. All objectively confirmed VTE episodes were collected and presented as CIR that was divided to total (VTE), aVTE and sVTE. Statistical analysis was performed using R, The R Project 4.0.3 Software.
Results: 
CIR of VTE in Children with Different Blood Disorders
3-year CIR of VTE is found to be 34,8% (95%CI 31,3-38,7%, Pic. 1A.). Most of the VTE episodes were presented as aVTE (3-year CIR=28,9%; 95%CI 25,7-32,5%) and 3-year CIR of sVTE was more than 3 times less (3-year CIR=8,2%; 95%CI 5,8-11,5%). While highest aVTE rates were found in children with ALL and lymphomas, followed by AML, Hc and AA (Pic. 1B.), the majority of sVTE episodes were diagnosed in lymphoma, followed by ALL, Hc, AML and AA. More than a half of sVTE episodes were diagnosed in the first 6 months of treatment, with majority of episodes in children with lymphoma, Hc and AML diagnosed in first 3 months (Pic. 1C.).
Conclusions: 3-year CIR of VTE in hospitalized children with different blood diseases is as high as 34,8% (95%CI 31,3-38,7%, Pic. 1A.) and is presented mainly with aVTE. The highest CIR of sVTE episodes were found in patients with lymphomas with majority of episodes diagnosed in first 3 months of treatment.
To cite this abstract in AMA style:
A Zharkov P, A Evstratov D, A Voronin K, V Fedorova D, V Pshonkin A. VTE Incidence in Children with Different Blood Disorders: Data from a Large Monocenter Retrospective Cohort Study [abstract]. Res Pract Thromb Haemost. 2021; 5 (Suppl 2). https://abstracts.isth.org/abstract/vte-incidence-in-children-with-different-blood-disorders-data-from-a-large-monocenter-retrospective-cohort-study/. Accessed June 25, 2022.« Back to ISTH 2021 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/vte-incidence-in-children-with-different-blood-disorders-data-from-a-large-monocenter-retrospective-cohort-study/