Not Yet RecruitingPhase 4

The Effect of Dapagliflozin on Exercise and Cardiac Functional Status of Patients After Fontan Procedure

Hong Kong30 participantsStarted 2026-04

Plain-language summary

While the Fontan operation improves survival for patients with a functional single ventricle, complications like heart failure remain prevalent during follow-up, causing frequent hospitalizations and reduced quality of life. Currently, there are no evidence-based heart failure therapies or guidelines for patients with Fontan palliation. There is growing interest in using sodium-glucose cotransporter 2 inhibitors (SGLT2i) to optimize cardiac conditions in this group. SGLT2i's observed benefits relate to protective effects on cardiac energy metabolism, renal function, sympathetic activation, inflammation, oxidative stress, erythropoiesis, and vascular function. Therefore, SGLT2i may represent a new therapeutic agent to improve exercise capacity and ventricular function in patients with Fontan circulation. This prospective, open-label, single-arm clinical trial investigates the FDA-approved drug dapagliflozin. An open-label design is utilized due to the relatively small cohort of patients with complex underlying hearts. The trial will be conducted at Hong Kong Children's Hospital (the sole pediatric cardiology center in Hong Kong) and Queen Mary Hospital (the largest tertiary referral center for adult congenital heart patients). The total study duration is 2 years. Subjects will participate for 3 months, receiving oral dapagliflozin 10mg once daily. The primary endpoint is VO2 max (maximum rate of oxygen consumption) during cardiopulmonary exercise testing at 3 months. Secondary assessments include questionnaires, history taking, physical examinations, 12-lead electrocardiogram, blood tests, echocardiography, bioelectrical impedance analysis, and urine pregnancy tests. If the hypothesis holds true, clinical translation of this project will: i) Improve long-term outcomes and quality-of-life for Fontan patients, reducing the healthcare burden from repeated heart failure hospitalizations; ii) Revolutionize the management of Fontan-associated heart failure by introducing SGLT2i as a novel, evidence-based therapy locally and globally; iii) Pave the way for multicenter international trials evaluating SGLT2i in the Fontan population and broader congenital heart diseases.

Who can participate

Age range

12 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria: * Patients with a functional single ventricle and who have undergone Fontan procedure * Adolescents aged ≥ 12 years with body weight ≥30kg and adults Exclusion Criteria: * Planned cardiac and/or non-cardiac surgery in 3 months * Arrhythmias requiring change in therapy in recent 6 months * Intervention procedure within 6 months prior to enrollment * Documented structural abnormalities of the Fontan circulation * Chronic kidney disease stages 4 to 5 * Inability to perform cardiopulmonary test * Recent use of SGLT2 inhibitors within 6 months * Known hypersensitivity to SGLT2 inhibitors * History of diabetic ketoacidosis * Recent symptomatic hypoglycaemia within 6 months * Insulin dependent diabetes mellitus * History of perineum infection * Recent urinary tract infection within 6 months * Recent genital infection within 6 months * Other known contraindications to SGLT2 inhibitor * Pregnancy or breast feeding

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Maximal oxygen uptake (VO2 max) on cardiopulmonary exercise (CPX) at 3 months

Timeframe: At Visit 3 (3 months)

Trial details

NCT IDNCT07482943

SponsorThe University of Hong Kong

Sponsor typeOTHER

Study typeINTERVENTIONAL

Primary completion2028-04

Contact for this trial

Prof Yiu Fai Cheung

+852-35133888 xfcheung@hku.hk

View on ClinicalTrials.gov More Fontan trials