Antithrombin Concentrate Use in Children Receiving Unfractionated Heparin for Acute Thrombosis

Area of Science:

• Pediatric Thrombosis Management
• Pharmacology and Therapeutics
• Hematology

Background:

• Acute thrombosis in children often requires anticoagulation therapy.
• Unfractionated heparin (UFH) is a common anticoagulant, but achieving therapeutic levels can be challenging.
• Antithrombin concentrate (ATC) may be used to augment UFH efficacy.

Purpose of the Study:

• To characterize the use of antithrombin concentrate (ATC) in pediatric patients undergoing unfractionated heparin (UFH) therapy for acute thrombosis.
• To evaluate the impact of ATC on antithrombin (AT) and anti-factor Xa levels.
• To identify factors influencing the response to ATC and assess associated risks.

Main Methods:

• Retrospective analysis of pediatric patients receiving ATC with UFH for acute thrombosis at Texas Children's Hospital (February 2011 to May 2013).
• Data collected included patient demographics, thrombosis type, baseline AT levels, UFH dosage, ATC dosage, and anti-factor Xa activity.
• Assessment of changes in AT and anti-factor Xa levels post-ATC administration and incidence of adverse bleeding events.

Main Results:

• Fifty-one children (median age 3 months) received ATC for venous, arterial, or intracardiac thrombosis.
• A single dose of ATC significantly increased AT and anti-factor Xa levels (P < .001) without substantial changes in UFH dose.
• No correlation was found between ATC dose or AT increment and achieving targeted anticoagulation; bleeding occurred in 10% of patients.

Conclusions:

• ATC administration leads to significant increases in AT and anti-factor Xa levels in pediatric patients on UFH therapy for acute thrombosis.
• The effectiveness of ATC in facilitating anticoagulation with UFH is variable and influenced by multiple factors.
• Careful consideration of bleeding risks and other potential adverse events is crucial when using ATC in this population.