COMPASS is a prospective multicenter randomized interventional trial. Participants with ductal-dependent pulmonary blood flow will be randomized to receive either a systemic-to-pulmonary artery shunt or ductal artery stent. Block randomization will be performed by center and by single vs. two ventricle status. Participants will be followed through the first year of life.

In neonates with ductal-dependent blood flow there remains valid uncertainty regarding the comparative benefits of ductal artery stent (DAS) with the traditional systemic-to-pulmonary artery shunt (SPS) palliation due to the lack of previous multicenter studies. COMPASS is a prospective multicenter randomized interventional trial where participants will be randomized to receive either an SPS or DAS to compare rates of a composite major morbidity/mortality endpoint in the first year of life. The study objectives are to perform an intention-to-treat analysis of participants' outcomes, and to describe the failure rate for neonatal candidates for DAS and the impact of this failure on the post-SPS course. Participants will be followed through the first year of life.

Inclusion Criteria:

1. Neonates with Congenital Heart Disease (CHD) and ductal-dependent pulmonary blood flow requiring only a stable source of pulmonary blood flow as the initial palliation, for whom the clinical decision is made at the enrolling center that this is best achieved by either DAS or SPS.
2. Age ≤ 30 days at time of index procedure (DAS or SPS).

Exclusion Criteria:

• 1. Any patient for whom the clinical decision at the enrolling center is that an initial intervention other than DAS or SPS is indicated (e.g., Right Ventricle-Pulmonary Artery (RV-PA) conduit, Right Ventricular Outflow Tract (RVOT) stent, primary complete anatomic repair, etc.).

  2. Pulmonary Atresia with Intact Ventricular Septum (PA/IVS) where Right Ventricle (RV) decompression is planned.

  3. Presence of MAPCAs: defined as an aortopulmonary collateral that is expected to require unifocalization.

  4. Non-confluent Pulmonary Arteries (i.e., isolated Pulmonary Artery (PA) of ductal origin).

  5. Acutely jeopardized branch Pulmonary Arteries (>75% narrowing of proximal PA based on screening cross sectional imaging [Computed Tomography Angiography (CTA) or cardiovascular Magnetic Resonance (cMR)]).

  6. Bilateral Patent Ductus Arteriosis (PDA). 7. Patient who, at the time of enrollment, is deemed not to be a candidate for eventual Glenn or Complete Surgical Repair (CSR) for any reason.

  8. Birth weight <2.0 kg. 9. Gestational age <34 weeks at birth. 10. Patient for whom additional intervention is expected concomitant with, or prior to, DAS or SPS (e.g., atrial septostomy, aortic arch intervention, or RV outflow tract intervention) - except for branch PA arterioplasty or stent/balloon angioplasty.

  11. Major co-morbidities which, in the opinion of the investigator, would negatively alter expected 1-year survival (e.g., intracranial hemorrhage, renal failure, etc.).

  12. Specific known genetic anomaly which, in the opinion of the investigator, would be expected to significantly alter clinical course in the first year of life (e.g., Trisomy 13/18, CHARGE, VACTERL).

  13. Patient who does not plan to return to the enrolling center or another participating center for Glenn/CSR.

All individual participant data collected by the Data Coordinating Center will be shared after posting of results and main study results publication.

Protocol and Informed Consent Form will be shared within 12 months of publication of study results. Public Use Dataset will be made available after publication, timeframe to be decided.

Protocol and Informed Consent Form will be made available with results on clinicaltrials.gov. Public Use Dataset will be available on the Pediatric Heart Network public website and may be used in accordance with Pediatric Heart Network governance.

Study staff and participants' families will be aware of treatment group due to the nature of the interventions.