The impact of quality and duration of enoxaparin therapy on recurrent venous thrombosis in children

Authors

  • Jeremie H. Estepp MD,

    Corresponding author
    1. Department of Hematology, St. Jude Children's Research Hospital, Memphis, Tennessee
    2. Department of Oncology, St. Jude Children's Research Hospital, Memphis, Tennessee
    • Department of Hematology, St. Jude Children's Research Hospital, M/S 800, 262 Danny Thomas Place, Memphis, TN 38105-3678.
    Search for more papers by this author
  • Matthew Smeltzer MStat,

    1. Department of Biostatistics, St. Jude Children's Research Hospital, Memphis, Tennessee
    Search for more papers by this author
  • Ulrike M. Reiss MD

    1. Department of Hematology, St. Jude Children's Research Hospital, Memphis, Tennessee
    Search for more papers by this author

  • Conflict of interest: Nothing to declare.

Abstract

Background

Venous thromboembolism (VTE) and recurrent venous thromboembolism (rVTE) are rare, but significant problems in pediatrics. Current recommendations for anticoagulant therapy arise from adult literature, and there is little data on clinical outcomes following therapeutic low-molecular-weight heparin in children.

Method

All patients <19 years of age that were diagnosed with a VTE or right atrial thrombus via standard imaging methods at St. Jude Children's Research Hospital were retrospectively identified from January 2004 through August 2008. Demographic characteristics, coexisting clinic conditions, description of anticoagulant therapy, and record of rVTE were chronicled following a comprehensive chart review. Descriptive statistics of clinical characteristics and anticoagulation are presented.

Results

Venous thrombosis was identified in 149 children with 21% (31/149) developing a rVTE. Coexisting clinical conditions were identified in 93% of children at initial diagnosis with 48% (71/149) of patients having a coexisting malignancy. Seventy-seven percent (114/149) of children received anticoagulant therapy with UFH (10/114) or enoxaparin (104/114). Neither duration of enoxaparin therapy (>6, 3–6, <3 months) (P = 0.61), nor quality of therapy (≥75% of time on anticoagulation spent with an anti-FXa of 0.5–1.0 U/ml) (P = 1.0) were found to be protective against rVTE.

Conclusion

Anticoagulation with enoxaparin based on adult literature may be suboptimal in preventing rVTE in pediatric populations. Future prospective randomized controlled trials in pediatrics using clinical outcomes with anticoagulant therapy are urgently needed. Pediatr Blood Cancer 2012; 59: 105–109. © 2011 Wiley Periodicals, Inc.

Ancillary