Establish a cardiovascular biomarker profile to help screening for congenital heart disease in infants and children as well as use non-invasive cardiac imaging in combination with such profiling to better predict the need for future cardiac interventions such as open heart surgery or cardiac catheter intervention in selected types of with congenital heart disease.

Analysing circulating cardiovascular biomarkers using blood samples should improve identification of congenital heart disease in newborns, in particular for those needing future cardiac interventions.

Comparing such biomarker profiles and non-invasive cardiac imaging results over time in infants and children should lead to better understanding of the complex cardiovascular remodelling processes in common congenital heart lesions, such as atrial or ventricular septal defects. This in turn should lead to an improved risk factor assessment model to guide treatment decisions in children with congenital heart disease in the foreseeable future.

To test our hypothesis, that cardiovascular biomarker profiling and non-invasive cardiac imaging findings in infants and children with congenital heart disease, differs from healthy controls, we will assess controls at enrolment and follow cases with predefined congenital heart disease lesions over a maximum of three years or up till one year after open heart surgery / cardiac catheter intervention to correct such lesions.

Infants and children resident in designated healthcare regions of Sweden will be invited to participate after study advertisement. Written informed consent will be obtained from legal guardians and assent will be sought from children who can communicate verbally with the dedicated paediatric research team.

Healthy subjects 0-17 years at enrolment will undergo i.e. standard electrocardiogram (ECG), echocardiography and blood sampling to evaluate the heart's anatomy and function and to obtain samples for subsequent blood-based biomarker analyses.

Additionally, saliva may be sampled and/or neonatal blood samples from national biobank storage will be retrieved for comparison with cardiovascular biomarker profiles in these controls if available.

To evaluate these cardiovascular assessments in predefined age groups, a subgroup of these participating subjects will be asked to complete additional cardiac magnetic resonance imaging based on study protocols.

Incidental findings of congenital heart disease will be followed up according to standard care protocols in designated paediatric cardiology clinics throughout the participating healthcare regions in Sweden.

A subgroup of cases with congenital heart disease that lead to pulmonary over-circulation, such as atrial and ventricular septal defects, partial anomalous pulmonary venous drainage, aorto-pulmonary windows and patent ductus arteriosus, will be asked to participate if the lesion has not been treated by open heart surgery or cardiac catheter interventions at enrolment.

Subjects with these predefined types of congenital heart disease aged 0-17 years at enrolment will undergo standard electrocardiograms (ECG), echocardiography and blood sampling to assess biomarkers at baseline and at 6-12 month follow-up intervals in dedicated paediatric cardiology clinics over a maximum period of three years.

Saliva samples and/or cardiovascular tissue obtained during open heart surgery may also be analysed for studied cardiovascular biomarkers. Additionally, neonatal blood samples from national biobank storage will be retrieved for comparison with current biomarker profiles if available.

For those congenital heart disease cases referred for open heart surgery or cardiac catheter intervention to correct the congenital heart lesion based on standard care assessment decisions during the study period, follow-up will end one year after such intervention. To evaluate cardiovascular assessments in predefined age groups, a subgroup of participating cases will be asked to complete additional cardiac magnetic resonance imaging based on study protocols.

Prospective evaluation of developed blood-based biomarkers assays and novel cardiac imaging biomarkers of heart function in infants and children will be further assessed to evaluate the feasibility of these methods to timely and precisely identify newborns with congenital heart disease by combined blood-based biomarker analyses and to assess whether newly identified functional parameters on heart function would be suitable to guide clinical risk-assessment and decision-making processes in terms of type and timing of cardiac interventions . These imaging biomarkers will, for example, evaluate the usefulness of measuring kinetic energy within the left ventricle of the heart in children with congenital heart disease based on magnetic resonance and echocardiography methods.

Inclusion Criteria:

• obtained written informed consent prior to enrolment
• resident within participating healthcare regions in Sweden during study
• age 0-17 years at enrolment
• Controls: No evidence of congenital heart disease and no history of cardiovascular disease
• Cases: congenital heart lesions prior to open heart surgery or cardiac catheter intervention with grouping into i.e. ventricular septal defects and atrial septal defects, complex and critical cases requiring infant surgery or patency of the arterial duct to maintain the circulation postnatally.

Exclusion Criteria:

• inability to obtain written informed consent prior to study enrolment and/or comply with study protocol
• non-resident in participating healthcare regions of Sweden during study
• age more than 17 years at enrolment
• presence of congenital heart disease where the lesion has already been treated by open heart surgery or cardiac catheter intervention
• participation in other research study with conflicting aims / interests

Anonymised clinical data relevant to the publication process of peer-reviewed scientific journals may be made available on request.

December 2024

After conclusion of the study, anonymised clinical data may be may available after reasonable request to medical researcher in recognised non-profit academic institutions

Participant and standard clinical care providers will be blinded to biomarker analyses and advanced cardiac imaging findings throughout the study