Efficacy of Phosphodiesterase-type 5 Inhibitors in Patients With Univentricular Congenital Heart Disease

• Status: Not yet recruiting
• Trial end date: 2026-06-01
• Target enrollment: 0
• Participant gender: All

Summary

In univentricular hearts, selective lung vasodilators such as phosphodiesterase type 5 (PDE5) inhibitors would decrease pulmonary resistance and improve exercise tolerance. However, the level of evidence for the use of PDE5 inhibitors in patients with a single ventricle (SV) remains limited. the investigators present the SV-INHIBITION study rationale, design and methods.The SV-INHIBITION trial is a nationwide multicentre, randomised, double blind, placebo-controlled, phase III study, aiming to evaluate the efficacy of sildenafil on the ventilatory efficiency during exercise, in teenagers and adult patients (>15 y.o.) with a SV. Patients with pulmonary arterial hypertension (mean pulmonary arterial pressure (mPAP) > 15 mmHg and trans-pulmonary gradient > 5 mmHg) measured by cardiac catheterisation, will be eligible. The primary outcome is the variation of the VE/VCO2 slope, measured by a cardiopulmonary exercise test, between baseline and 6 months of treatment. A total of 50 patients are required to observe a decrease of 5 ± 5 points in the VE/VCO2 slope, with a power of 90% power and an alpha risk of 5%. The secondary outcomes are: clinical outcomes, 6 minute walk test, SV function, NT Pro BNP, VO2max, stroke volume, mPAP, trans-pulmonary gradient, SF36 quality of life score, safety and acceptability. This study aims to answer the question whether PDE5 inhibitors should be prescribed in patients with a SV. This trial has been built focusing on the 3 levels of research defined by the WHO: disability (exercise tolerance), deficit (SV function), and handicap (quality of life).

• Phase: Phase 3
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: University Hospital, Montpellier
• Treatments: Phosphodiesterase 5 Inhibitors; Sildenafil Citrate

Criteria

Inclusion Criteria:

1. 15 years of age and over.

2. Patient's weight over 20 kg

3. Patients with CHD with a single ventricular type defined by the classification of congenital heart diseases in Orphanet (53).

4. PAH defined by diagnostic catheterization with mean PAP > 15 mmHg and a trans-pulmonary gradient > 5 mmHg, performed as part of the usual follow-up. No definition of PAH in SV is available as a result of a particular physiology. Therefore, we chose the 15mmHg cut-off, which is used in clinical routine to allow or contra-indicate the Fontan procedure [50,51].

5. Appropriate written informed consent (adult patients, legal parents for teenagers), and formal assent (teenagers), should to be provided.

6. Beneficiary of a health insurance.

Exclusion Criteria:

1. Patient who is unable to perform a cardio-pulmonary exercise test.

2. Cardiac surgery planned during the trial.

3. Patient treated by any pulmonary arterial vasodilator drug, as defined in the 2015 PH guidelines (52), within 6 months before inclusion, regardless the duration and the type(s) (oral, intravenous, subcutaneous, inhaled) of administration.

4. Patient treated by Sildenafil or any other type of phosphodiesterase-type 5 inhibitor (such as tadalafil) within 6 months before inclusion, regardless the duration of administration.

5. Interventional cardiac catheterization planned during the trial (collateral occlusion, fenestration occlusion, stenting, angioplasty, ablation of rhythm disorder), other than during the screening.

6. Participation in another clinical trial or administration of an off-label drug in the 4 weeks preceding the screening.

7. Pregnancy, desire for pregnancy, absence of contraception during the study period.

8. Severe hepatic insufficiency (Child-Pugh C class).

9. Hypersensitivity to the active substance or to any of the excipients of the tablet:

microcrystalline cellulose, calcium hydrogen phosphate anhydrous, croscarmellose sodium, stearate of magnesium, hypromellose, titanium dioxide (E171), monohydrate lactose, glycerol triacetate.

10. Combination with products called "nitric oxide donors" (such as amyl nitrite) or with nitrates in any form, due to the hypotensive effects of nitrates.

11. Concomitant administration of PDE5 inhibitors, such as Sildenafil, with guanylate cyclase stimulators, such as Riociguat.

12. Combination with the most potent inhibitors of CYP3A4 (eg ketoconazole, itraconazole, ritonavir).

13. Disposition to priapism, sclerosis of corpora cavernosa, disease of La Peyronie, sickle cell anemia, multiple myeloma, leukemia.

14. Uncontrolled hypotension or risk of hypotension: water depletion, obstruction to ejection of the left ventricle, dysfunction of the autonomic nervous system, patient under alpha-blocker.

15. Severe cardiovascular events, recent (<3 months) or not stabilized: myocardial infarction, unstable angina, sudden cardiac death, ventricular arrhythmia, cerebrovascular hemorrhage.

16. Active hemorrhagic disorders.

17. Active gastro-duodenal ulcer.

18. Patients with loss of vision of an eye due to non-arteritic anterior ischemic optic neuropathy (NAION), whether or not this event has been associated with previous exposure to a PDE5 inhibitor.