Asymptotic Venous Thrombosis Clinical Trial
Official title:
A Randomized Controlled Trial of Enoxaparin in Children With Asymptomatic Venous Thrombosis After Pediatric Cardiac Surgery
The CATCH-enoxaparin trial is the natural continuation of the CATCH study. It will
capitalize on the fact that patients enrolled in the CATCH study will be specifically
screened for asymptomatic thromboembolism (TEs) in order to answer important clinical
questions.
The investigators propose a randomized controlled trial to address whether, among pediatric
patients with congenital heart defects (CHD) recovering from cardiovascular surgery and
diagnosed with an asymptomatic venous TE, the use of enoxaparin results in a net therapeutic
benefit?
Primary Aim: To address whether, among pediatric patients with congenital heart defects
(CHD) recovering from cardiovascular surgery and diagnosed with an asymptomatic venous TE,
the use of enoxaparin results in a net therapeutic benefit. We hypothesize that enoxaparin
dosed as per age-appropriate algorithms is associated with an increased rate of clot
resolution and decreased rate of clot progression/long-term complications in children with
CHD and asymptomatic venous TE. Benefits from clot resolution will outweigh the risks
associated with the use of enoxaparin resulting in a net therapeutic benefit in favour of
enoxaparin use in this context.
Secondary aims of this study are to:
1. To compare the rate of conversion from asymptomatic to symptomatic TE and/or
thromboembolic events between treated and untreated patients. Hypothesis: the use of
enoxaparin will significantly reduce the rate of conversion from asymptomatic to
symptomatic TE.
2. To compare the rate of objective clot progression (or regression) by serial imaging
with ultrasound and echocardiography between treated and untreated patients.
Hypothesis: the use of enoxaparin will significantly increase the rate of clot
regression.
3. To identify factors associated with: TE conversion from asymptomatic to symptomatic,
clot resolution and post-thrombotic syndrome in both treated and untreated patients
separately. Hypothesis: older children with a more mature coagulation system and those
with TEs in superficial vessels (rather than deep/systemic vessels) will have a lower
frequency of TE complications.
4. To establish the rate of bleeding complications (both minor and major) for patients on
enoxaparin. Hypothesis: we expect major bleeding complications to be present in 2-3% of
treated patients and minor bleeding complications to be frequent.
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Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Treatment