An observational study in Fontan Procedure and Fontan Circulation, sponsored by Universidad de Murcia. Not yet recruiting. Open to participants aged 14 Years and older. Per ClinicalTrials.gov, last updated 2026-10-14.
Sponsored by Universidad de Murcia · Observational
This is a multicenter, observational, cross-sectional study designed to investigate whether a parsimonious set of low-cost, accessible functional, anthropometric, and physiological measurements can help identify multisystem clinical-physiological impairment in patients with Fontan circulation.
Fontan circulation is associated with long-term multisystem complications affecting cardiac, cardiopulmonary, hepatic, renal, nutritional-lymphatic, hematological, and metabolic function. Current surveillance may require multiple specialized, costly, and time-consuming investigations. This study will explore whether simple and easily repeatable measurements can provide an accessible complementary approach for the initial functional and clinical assessment of these patients.
Approximately 150 participants aged 14 to 60 years with Fontan circulation, recruited from 18 Spanish healthcare centers, will be included. Participants must have undergone Fontan surgery at least 2 years before inclusion and be clinically stable in outpatient follow-up.
Each participant will attend one study-specific visit lasting approximately 45-60 minutes. During this visit, functional, anthropometric, and physiological variables will be assessed. Functional measurements will include squat jump performance using the Samozino method and the five-times sit-to-stand test (5xSTS) using the Alcázar method. Anthropometric measurements will include body mass index, age- and sex-adjusted anthropometric indicators of muscularity, and calf and thigh circumferences. Physiological measurements will include resting heart rate and oxygen saturation, heart rate recovery after the 1-minute sit-to-stand test, and post-exercise oxygen saturation.
Clinical, laboratory, echocardiographic, and functional data obtained as part of routine clinical follow-up will also be collected. Whenever possible, routine clinical measurements will correspond to assessments performed on the same day as the functional evaluation; measurements obtained within a maximum window of ±15 days will also be considered.
The primary analysis will evaluate the association between the candidate low-cost measurements and the presence of clinical-physiological impairment affecting two or more organ or functional domains. Additional analyses will investigate their ability to identify patients with impairment in at least one domain and to discriminate increasing levels of multisystem clinical-physiological burden.
The study will not involve any therapeutic intervention or prospective study-specific follow-up. The results will be interpreted as cross-sectional associations and will not establish causal or longitudinal prognostic relationships.
Universidad de Murcia is the lead sponsor of 79 studies on the registry; 17 are open to participants now.
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Population undergoing the Fontan procedure residing in Spain
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Patients who meet the following criteria will be eligible to participate in the study: having undergone Fontan surgery at least 2 years prior to enrollment; being between 14 and 60 years of age; be under stable outpatient follow-up by the corresponding clinical unit; and voluntarily agree to participate by signing an informed consent form after having been informed verbally and in writing about the objectives, procedures, risks, and potential benefits of this study. For participants who are minors, consent from their legal guardians and the minor's assent will be requested when appropriate.
Exclusion Criteria:
Patients with an unstable outpatient clinical condition will be excluded, including those scheduled for reoperation or an invasive procedure within 3 months of the evaluation; patients in NYHA functional class IV (symptoms of heart failure even at rest and an inability to perform any physical activity without discomfort. Even minimal exertion may increase dyspnea, fatigue, or palpitations); the presence of physical, neuromuscular, orthopedic, or functional limitations that prevent the safe performance of the motor tasks required for the squat jump or for standing up from a chair; pregnancy; or refusal to participate in the study.
Multisystem clinical-physiological impairment affecting ≥2 domains
Presence of clinical-physiological impairment affecting two or more predefined domains, based on clinical, laboratory, echocardiographic and functional variables obtained during routine follow-up. The domains include cardiopulmonary, cardiac, hepatic, renal, nutritional-lymphatic, and hematological-metabolic domains.
Time frame: At the study assessment / cross-sectional assessment (single study visit)
Clinical-physiological impairment affecting ≥1 domain
Presence of impairment in at least one predefined clinical-physiological domain.
Time frame: At the study assessment / cross-sectional assessment
Multisystem clinical-physiological burden
Ordinal level of clinical-physiological burden according to the number of affected domains: 0, 1, 2, or ≥3 domains.
Time frame: At the study assessment / cross-sectional assessment
Discriminative capacity of low-cost functional, anthropometric and physiological variables
Ability of the candidate low-cost variables to discriminate participants according to the presence and degree of clinical-physiological impairment, assessed using AUC, sensitivity, specificity and predictive values.
Time frame: At the study assessment / cross-sectional assessment
Association between candidate low-cost variables and clinical-physiological impairment
Association of functional, anthropometric and physiological variables with the presence of multisystem impairment. Candidate variables include squat jump parameters, 5xSTS performance, anthropometric measures, resting heart rate, oxygen saturation, heart-rate recovery after 1-minute sit-to-stand and post-exercise oxygen saturation.
Time frame: At the study assessment / cross-sectional assessment
No study locations are listed for this record.
Start is estimated for Jan 2027; primary completion for Jul 2027, 6 months later.
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From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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Universidad de Murcia