Microcirculation and Vascular Function After Fontan Surgery

Congenital Heart Disease Clinical Trial

— MICROFON  

Official title:

Microcirculation and Vascular Function After Fontan Surgery

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT05683067
• Other study ID #: 0860
• Status: Recruiting
• Start date: May 12, 2023
• Est. completion date: October 1, 2024

Study information

• Verified date: July 2023
• Source: University of Leicester
• Contact: n/a
• Is FDA regulated: No
• Study type: Observational

Clinical Trial Summary

Fontan Surgery is done for children with only one working lower chamber of the heart called the 'Single Ventricle'. This surgery involves making connections between the two big veins that drain oxygen deficient blood to the heart and the lung artery directly. Fontan patients may develop long-term complications such as reduced heart function or oxygen levels, increased pressure in the veins, liver or kidney problems etc. The reasons for these complications are poorly understood. The small blood vessels in the body or 'microcirculation' are tiny (can be seen only by microscope) and they supply food and oxygen to the tissues. Very little is known about what happens to the microcirculation in adult Fontan survivors . In this study the investigator want to understand why these adult Fontan survivors develop complications by looking at their microcirculation and comparing them with healthy people and those who were operated for other congenital heart diseases. The study will be conducted in East Midlands Congenital Heart Centre, Glenfield Hospital.

Leicester.

Description:

In normal heart, there are two working lower chambers where one chamber pumps the blood to the lungs and other chamber pumps the blood to the body. However, some congenital heart conditions have only one working lower chamber of the heart called the 'Single Ventricle'. This condition is often associated with hole between the heart chambers with increased or decreased blood flow to the lungs. This can lead to mixing of blood in the heart with low oxygen levels in the body. The surgery for single ventricle is usually performed in stages starting from the infancy. Fontan surgery is the last stage where the two big veins that return the blood to the heart is connected to the lung artery directly. This surgery improves the oxygen levels in the blood and lessens the burden on the single ventricle. The blood is not pumped to the lungs by the heart but rather enters passively to the lungs through this new surgical connection. Some people operated for Fontan surgery have many short-term and long-term complications such as increased pressure in veins , poor heart function and low oxygen levels in the blood. In particular, the organs below the chest such as kidney, liver and gut are affected, and all of these predict poor outcomes. The reason for these complications are poorly understood.

The small blood vessels in the body or 'microcirculation' are very tiny and are less than 150 microns in diameter. These includes arterioles, capillaries, and venules. Very little is known about the microcirculation in adult Fontan survivors and its association with aortic stiffness, late complications, and quality of life. In this study, The investigators want to look at the blood vessels in adult Fontan survivors, people operated for other congenital heart diseases, and healthy volunteers using a special microscope called Hand Held Capillary Microscopy. The investigators will visualize their blood vessel appearance, number, and size they have in their hands, feet, and under the tongue. This procedure is non-invasive and will not cause any pain. The aortic stiffness will be measured non-invasively using a special blood pressure monitor called Mobile 'O' Graph, which is about size of a pocket diary. 24 hour blood pressure monitoring is optional. The investigator will also collect the information about the quality of life using questionnaires as few studies have shown that the quality of life is affected in adult Fontan survivors and it was associated with poor vascular function. Age matched healthy controls and adults survivors of other congenital heart surgeries will also undergo these tests for comparison purpose. This study will be conducted at East Midlands Congenital Heart Centre, Glenfield Hospital, Leicester.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 75
• Est. completion date: October 1, 2024
• Est. primary completion date: October 1, 2024
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 16 Years to 50 Years

Eligibility

Inclusion Criteria:

• Patients operated for Fontan procedure or other congenital heart conditions

• Patients = 16 - 50 years of age

• Participant/Parents/Guardian or legal representative willing and able to give Informed Consent for participation in the study

• Able (in the Investigators opinion) and willing to comply with all study requirements

Exclusion Criteria:

• Low blood pressure (90/60 mmHg with symptoms or on intravenous inotropes for maintenance of blood pressure)

• Raynaud's disease

• Autoimmune diseases

• Down's syndrome as they have lower risk for vascular anomalies compared with the general population and may have different microvasculature

• Treatment with sympathomimetic drugs

• Atrial fibrillation or any other arrhythmia which might interfere with vascular function assessments.

• Documented peripheral vascular disease

• Skin disorders such as psoriasis or significant eczema

• Any other significant disease or disorder which, in the opinion of the Investigator, may either put the participants at risk because of participation in the study, or may influence the result of the study, or the participant's ability to participate in the study.

• Tremor or Inability to keep the hand still for 20 minutes.

Note: Patients treated with angiotensin converting enzyme inhibitors or angiotensin receptor inhibitors, beta blockers, vasodilators, diuretics and digoxin will be included in the study as the majority of Fontan survivors are taking one or more of these drugs for optimization of their circulation or for symptom management. Patients treated with anticoagulants and antiplatelets will be included in the study.

Related Conditions & MeSH terms

• Congenital Heart Disease
• Heart Defects, Congenital
• Heart Diseases

Intervention

Other:
• Hand Held Capillary Microscopy
The investigator will visualize the blood vessel appearance, number, and size they have in their hands, feet, and under the tongue. This procedure is non-invasive and will not cause any pain.
• Mobile 'O' Graph
The aortic stiffness will be measured non-invasively using a special blood pressure monitor called Mobile 'O' Graph, which is about size of a pocket diary. 24 hour blood pressure monitoring is optional.
• quality of life using questionnaires
The investigator will evaluate the quality of life using questionnaires such as EQ-5D-5L questionnaire and the Minnesota Living with Heart Failure Questionnaire (MLHFQ)

Locations

Country	Name	City	State
United Kingdom	Glenfield Hospital Leicester	Leicester	Leicestershire

Sponsors (1)

Lead Sponsor	Collaborator
University of Leicester

Country where clinical trial is conducted

United Kingdom, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	In this study, the investigator want to look at the microcirculation using hand held capillary microscopy in the young and adult Fontan survivors compared to the age matched healthy people and the people operated for other congenital heart surgeries.	The microcirculation will be studied in the skin of the hands, feet, and the mouth using handheld capillary microscopy	One year
Secondary	The investigator want to measure the central blood pressure in the young and adult Fontan survivors compared to the age matched healthy people and the people operated for other congenital heart surgeries.	The central blood pressure, pulse wave velocity, and the augmentation index will be assessed by Mobile O Graph blood pressure monitor	One year
Secondary	The investigator will measure the functional outcomes in young and adult Fontan survivors using questionnaires and study its relationship with microvascular assessments and vascular function.	The functional status will be assessed by Minnesota living with heart failure questionnaire	One Year