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?
|Study Design:||Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Treatment
|Official Title:||A Randomized Controlled Trial of Enoxaparin in Children With Asymptomatic Venous Thrombosis After Pediatric Cardiac Surgery|
- Net therapeutic benefit of enoxaparin [ Time Frame: Events recording from baseline to 18 months post-surgery ] [ Designated as safety issue: No ]Defined as the between group difference in proportion of patients with negative outcomes (percent clot conversion to symptomatic + percent major bleeding complications)
- Rate of objective clot size progression (or regression) [ Time Frame: Up to 18 months post-surgery ] [ Designated as safety issue: No ]This will be determined by serial imaging with ultrasound and frequency of complete clot resolution at the end of the treatment
- Frequency and Risk Factors for conversion from asymptomatic to symptomatic thromboembolism [ Time Frame: Up to 18months post-surgery ] [ Designated as safety issue: No ]Defined as the appearance of any of the following symptoms: swelling, edema, discoloration or high temperature of the affected territory
- Frequency of and risk factors for post-thrombotic syndrome [ Time Frame: 18 months after surgery ] [ Designated as safety issue: No ]Clinical manifestations include varicose veins, edema, skin hyperpigmentation and skin ulcers
- Frequency of and risk factors for bleeding complications [ Time Frame: Up to 18months ] [ Designated as safety issue: Yes ]Minor complications and major episodes defined as cerebral, abdominal, retroperitoneal or pulmonary hemorrhage or any bleeding complications requiring blood transfusions
- Neurodevelopment and health re-lated quality of life [ Time Frame: 18 months post-surgery ] [ Designated as safety issue: No ]Age appropriate PedsQL® generic module and parent report and Child Health Questionnaire
|Study Start Date:||August 2011|
|Estimated Study Completion Date:||August 2015|
|Estimated Primary Completion Date:||August 2015 (Final data collection date for primary outcome measure)|
Experimental: Treatment group
The initial enoxaparin dose will be: 1.75 mg/kg/dose SC q12h for patients ≤ 2 months old or
1 mg/kg/dose SC q12h for patients > 2 months old
Adjust the dose of enoxaparin according to the following monogram. Depending on the Enoxaparin Anti-factor Xa level achieved, successive actions are indicated, including whether to hold the next scheduled dose, whether any dose change is indicated and when the next anti-factor Xa level should be drawn.
Lovenox- Enoxaparin; Sanofi-Aventis Canada Inc.
|No Intervention: No-treatment|
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:
- 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.
- 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.
- 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.
- 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.
|The Hospital for Sick Children|
|Toronto, Ontario, Canada, M5V1X8|
|Principal Investigator:||Brian W McCrindle, MD||The Hospital for Sick Children|