None listed
Conditions
Brief summary
A significant number of neonates and infants require systemic-to-pulmonary artery shunt procedures as a part of staged treatment of their congenital cardiac condition. These shunts are at risk of thrombotic occlusion. Shunt patency is critical for survival of these children. The interim mortality of shunt dependent children has been found to be as high as 14%, and about 33% of these are due to thrombosis of the shunt. Some eventually undergo correction of their cardiac anomalies while the remaining undergo further surgeries for a single ventricle palliation (Fontan pathway). The children with single ventricle palliation are dependent on the patency of their subsequent shunts for survival. They are at risk of life-threatening thrombosis throughout their lives. Cross-sectional surveys of post-Fontan patients have reported a prevalence of intracardiac thrombosis of 17% to 33% and incidences of venous thrombosis and stroke ranging from 3% to 19%. The reported mortality from post-Fontan surgery thromboembolism is 25%. Aspirin has been the cornerstone of thromboprophylaxis in such children and its use has been associated with a significantly lower risk of mortality. Unfortunately, not all children respond equally to aspirin with an increase in the dose of aspirin suggested to reduce the incidence of thrombosis in some while the remaining have no response to aspirin. The prevalence of aspirin unresponsiveness in adults is estimated to be 0.4 to 35%, however this information in lacking in the paediatric population. The primary objective of the study is therefore to determine the prevalence of aspirin resistance in children undergoing cardiac surgery in Queensland. Secondary objectives are: 1) to assess if response to aspirin is dose dependent and 2) assess the incidence of thrombosis in children who respond to aspirin.
Interventions
Participants in this study will have blood samples drawn to evaluate the effectiveness of aspirin therapy in pediatric patients undergoing heart surgery and who need anti-platelet therapy after surgery.
Administration of aspirin is standard for care for the participants of this study. Prior to this study and in most places around the world, aspirin is administered without testing for its efficacy.
Aspirin is initiated as soon as enteral feeding is initiated.
Frequency of aspirin test:
1. Be
Participants in this study will have blood samples drawn to evaluate the effectiveness of aspirin therapy in pediatric patients undergoing heart surgery and who need anti-platelet therapy after surgery. Administration of aspirin is standard for care for the participants of this study. Prior to this study and in most places around the world, aspirin is administered without testing for its efficacy. Aspirin is initiated as soon as enteral feeding is initiated. Frequency of aspirin test: 1. Before administration of aspirin 2. After at least 3 days of aspirin therapy 3. After at least 3 days of increased aspirin dose (only if not responsive to routine dose) Patients are followed up for 6 months post-surgery for evidence of clots
Sponsors
Children's Health Queensland Hospital and Health Service
Eligibility
Sex/Gender
All
Age
0 to 18 Years
Healthy volunteers
No
Inclusion criteria
• Age 0-18 years of age • Family/carer/patient able to provide informed consent. • Children who require aspirin thromboprophylaxis after cardiac surgery such as; • Systemic to pulmonary artery shunts • Cavo-pulmonary shunt • Fontan procedure • Right ventricle to pulmonary artery conduit implantation • Repairs involving large intra-cardiac baffles • Valve repairs • Any other patient receiving thromboprophylaxis with aspirin who does not meet the exclusion criteria
Exclusion criteria
• Patients with documented allergic reaction to aspirin • Patients in whom aspirin is contra-indicated due to past adverse reactions such as Reye’s syndrome or renal dysfunction • Patients on long-term anticoagulation with other drugs in addition to aspirin e.g. warfarin, clopidogrel or other antiplatelet medications. • Relative contraindication: Patients who had GI bleeds associated with aspirin in the past should be assessed carefully, but not excluded immediately, given that aspirin can cause gastritis in any patient if they are fasted, have a concurrent illness etc
Outcome results
None listed