Study of Tadalafil vs. Placebo for Improving Hemodynamics and End-Organ Dysfunction in Fontan Physiology

A Phase III, Randomized, Double-Blind, Placebo-Controlled Study Evaluating the Efficacy of Tadalafil Versus Placebo in Improving Hemodynamics and End-Organ Dysfunction in Fontan Physiology (TRIUMPH Trial)

The purpose of this study is to find out more about the effectiveness of Tadalafil in improving hemodynamic capabilities, endothelial function, and end-organ function in patients who have previously undergone a Fontan Palliation.

Study Overview

• Status: Recruiting
• Conditions: Fontan Palliation
• Intervention / Treatment: Drug: Placebo; Drug: Tadalafil

• Study Type: Interventional
• Enrollment (Estimated): 80
• Phase: Phase 3

Contacts and Locations

• Study Contact: Name: ACHD Research Team; Phone Number: 507-293-2565; Email: RSTACHDRESPRG@mayo.edu

Study Locations

• United States
  • Minnesota
    • Rochester, Minnesota, United States, 55905
      • Recruiting
      • Mayo Clinic
      • Contact: ACHD Research Team; Phone Number: 507-293-2565; Email: RSTACHDRESPRG@mayo.edu
      • Principal Investigator: Alexander C Egbe, MBBS, MPH

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Patients ≥ 18 years old.
• Have previously undergone a Fontan Palliation.
• Able to exercise using a supine bike.
• Ability and willingness to provide written consent.
• Undergoing a clinically indicated Cardiac Catheterization

Exclusion Criteria:

• Patients < 18 years old.
• Current intravenous inotropic drugs.
• Current use of alpha-blockers, pulmonary vasodilators, or nitrates.
• Unable to exercise.
• Pregnancy or lactating.
• Unable or unwilling to consent.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Tadalafil Group; Study participants will receive 10 mg of Tadalafil daily for 1 week, then 20 mg daily for 1 week, and finally 40 mg daily for 50 weeks for a total therapy time of 52 weeks. Tadalafil will be taken orally in capsule form once daily.	Drug: Tadalafil; 10 mg once daily orally week 1, 20 mg once daily orally during week 2, and 40 mg once daily orally during weeks 3 through 52
Placebo Comparator: Placebo Group; Study participants will receive a placebo capsule that looks identical to the Tadalafil capsule. The placebo will be taken orally once daily for 52 weeks.	Drug: Placebo; Looks exactly like the study drug, but it contains no active ingredient

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Microvascular endothelial function	Measured by the reactive hyperemic index using peripheral artery tonometry (EndoPAT)	52 weeks
Pulmonary vascular reserve	The slope of mean pulmonary artery pressure / cardiac output (mPAP/CO)	52 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Liver stiffness	Liver magnetic resonance elastography (MRE) will be used to assess liver stiffness expressed in Pascals (Pa)	52 weeks
Renal function	Measured by the glomerular filtration rate	52 weeks
Exercise capacity	Assessed using peak VO2 (oxygen consumption) obtained from an upright treadmill or supine bike cardiopulmonary exercise test with echocardiogram	52 weeks
Patient reported quality of life	Measured by the Minnesota Living with Heart Failure Questionnaire that asks subjects to rate how much their heart failure (heart condition) has affected their life during the past month (4 weeks) on a scale of 0=no and 5=very much.	52 weeks

Collaborators and Investigators

• Sponsor: Mayo Clinic
• Collaborators: National Heart, Lung, and Blood Institute (NHLBI)
• Investigators: Principal Investigator: Alexander C Egbe, MBBS, MPH, Mayo Clinic

Publications and helpful links

Helpful Links

• Mayo Clinic Clinical Trials

Study record dates

Study Major Dates

• Study Start (Actual): September 16, 2022
• Primary Completion (Estimated): November 1, 2026
• Study Completion (Estimated): November 1, 2026

Study Registration Dates

• First Submitted: January 12, 2022
• First Submitted That Met QC Criteria: January 12, 2022
• First Posted (Actual): January 25, 2022

Study Record Updates

• Last Update Posted (Estimated): November 14, 2025
• Last Update Submitted That Met QC Criteria: November 12, 2025
• Last Verified: November 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pyridines; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Indoles; Indole Alkaloids; Heterocyclic Compounds, 3-Ring; Carbolines; Tadalafil
• Other Study ID Numbers: 21-009890; R01HL160761-01 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No