Please assess the completion status of the following clinical trial:

Trial Title: Sildenafil in Single Ventricle Patients

Study Design Characteristics:
- Allocation: None
- Intervention Model: SINGLE_GROUP
- Observational Model: None
- Primary Purpose: TREATMENT
- Time Perspective: None
- Masking: NONE
- Phase: PHASE1
- Number of Arms: 1.0

Eligibility Criteria:
Inclusion Criteria:~1. Age ≥ 3 months; ≤120 months.~2. History of congenital heart disease with severe hypoplasia of a right or left ventricle.~3. Undergoing cardiac catheterization as part of standard clinical care.~4. Availability and willingness of the parent/legally authorized representative to provide written informed consent.~Exclusion Criteria:~1. History of serious adverse event related to sildenafil administration.~2. History of sildenafil exposure within 48 hours of the study.~3. Presence of pulmonary venous obstruction.~4. Treatment with organic nitrates or alpha blockade therapy.~5. Contraindication to cardiac catheterization as determined by the attending cardiologist and including:~   1. Significant hemodynamic instability.~  2. Sepsis.~  3. Need for Extra-Corporeal Membrane Oxygenation (ECMO) support.~  4. Venous occlusion precluding adequate access.~  5. Recent systemic illness.~6. Renal failure defined as serum creatinine \> 2 times higher than the upper limit of normal.~7. Liver dysfunction defined as alanine aminotransferase or aspartate aminotransferase \> 3 times higher than the upper limit of normal.~8. Thrombocytopenia defined as a platelet count \< 50 000 cells/µL.~9. Leukopenia defined as white blood cells \< 2500 cells/µL.

- Gender: ALL
- Minimum Age: 3 Months
- Maximum Age: 120 Months
- Healthy Volunteers: f

Study Arms:
- Sildenafil (Type: ACTIVE_COMPARATOR): Pharmacokinetic and hemodynamic evaluation following sildenafil administration

Based on this trial design, predict the completion outcome and termination type (if applicable).