Genetic Determinants of Congenital Heart Disease Outcomes

Study Overview
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Brief Summary
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The purpose of this study is to examine the role of genetic variation in the oxidative stress response on critical perioperative and short-term outcomes after neonatal heart surgery. The goals will be to determine 1) if the oxidative stress pathway is an important one for therapeutic intervention in neonates with severe congenital heart defects and 2) if variants in the oxidative response pathway can be used to identify patients at increased risk for adverse outcomes.

Detailed Description
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For physicians caring for children with congenital cardiac defects, perhaps the greatest challenge is to improve the survival and functional outcomes of patients with severe defects requiring surgical repair or palliation in the first month of life. These cardiac defects can be associated with 5 year mortality rates of up to 30% with significant disabilities in many of the survivors. As with every medical condition, patient outcomes depend on the complex interaction of the disease process, the medical and surgical interventions to treat the disease, and the inherent capacity of the patient to respond to both the disease and its treatment. For patients with severe cardiac defects, the greatest risk for morbidity and mortality occurs during and shortly after their neonatal surgical repair. During surgery to repair severe cardiac defects, the body is cooled and the heart is stopped. In many cases, blood flow to the vital organs is interrupted or restricted for a significant period of time while the aortic arch is reconstructed. This process places profound stress on the patient's capacity to tolerate these insults without sustaining irreversible injury to tissues such as the heart, brain, and kidneys. That there is such a wide range of outcomes after this surgery, even between patients with similar clinical features, suggests that there are important individual differences in patients' abilities to respond to this stress that is determined by differences in their genetic traits. The importance of the interaction between the controlled trauma of the surgical environment and a patient's genetic background in determining patient outcomes has led to the new discipline of peri-operative genomics. In this study, we will examine the contribution of gene-environment interactions to perioperative and short-term outcomes in neonates with severe congenital cardiac defects.

Official Title
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The GECHO Trial: Genetic Determinants of Congenital Heart Disease Outcomes

Conditions
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Congenital Heart Disease, Hypoplastic Left Heart Syndrome, Hypoplastic Right Heart Syndrome, d-Transposition of the Great Arteries

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: d-transposition of the great arteries or single ventricle cardiac disease Less than or equal to 30 days of age Planned arterial switch operation or stage I surgical palliation (Norwood)with aortic arch reconstruction Exclusion Criteria: Known trisomy 13, 18, or 21 Any major non-cardiac anomaly that precludes the patient from cardiac surgery

Ages Eligible for Study
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Maximum Age: 30 Days

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| d-Transposition of the Great Arteries<br>Neonates with d-transposition of the great arteries (dTGA) undergoing the arterial switch operation with cardiopulmonary bypass | |
| Single ventricle cardiac disease<br>Neonates with single ventricle cardiac disease (SVCD) undergoing stage I surgical palliation (Norwood) with cardiopulmonary bypass | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Contribution of genetic variation in oxidative stress management to differences in short term outcomes after repair for severe cardiac disease in the neonatal period | Genotyping will be performed on 10 variants in the oxidative stress response pathway and we will combine risk genotypes in order to evaluate the cumulative effect of both detrimental and beneficial alleles on post-operative outcomes. Composite short term outcome measure includes: ICU length of stay (days) Time to initial extubation (hours) Cardiac arrest or ECMO support (Y/N) Delayed sternal closure (Y/N) Serious adverse event (Y/N) Greater than 1 serious adverse event (Y/N) | Duration of initial perioperative hospitalization ( 2-4 weeks) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Contribution of genetic variation in oxidative stress management to differences in interstage mortality and pre-Stage II cardiovascular function in patients with single ventricle cardiac disease | Composite outcome Growth parameters (height, weight, head circumference) AV valve insufficiency (By echocardiogram and cardiac catheterization) , Ventricular function (ejection fraction by echocardiogram and by cardiac catheterization), Central venous pressure and ventricular end diastolic pressure (by catheterization), Interstage Death (Y/N). | Interval from hospital discharge following stage I surgical palliation until hospital admission for stage II surgical palliation ( 4-6 months of age) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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congenital heart disease, neonate, single ventricle cardiac disease, hypoplastic left heart syndrome, hypoplastic right heart syndrome, d-Transposition of the Great Arteries