Assessment of Osteoblastic Activity With 18F-Fluoride in Aortic Bioprosthesis Structural Valve Dysfunction (SVD)

Study Overview
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Brief Summary
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Structural valve dysfunction (SVD) is the most common and life threatening complication in patients treated by aortic valve replacement. A calcification process is frequently involved in SVD but its pathophysiology remains unclear. In the hypothesis of an active metabolic phenomenon of calcification, as previously shown in native aortic valve stenosis, rather than a passive deposit of calcium in valve tissue, positon emission tomography (PET) imaging with 18F-Fluoride could emphasize increased osteoblastic activity in SVD tissue. This study will include patients with echocardiography-confirmed SVD. Echocardiographic parameters and other current parameters analyzed in SVD patients such as bioprosthesis calcium scoring derived from CT will be compared to 18F-Fluoride activity.

Official Title
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Assessment of Osteoblastic Activity With 18F-Fluoride in Aortic Bioprosthesis Structural Valve Dysfunction (SVD)

Conditions
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Aortic Bioprosthesis Structural Valve Dysfunction

Intervention / Treatment
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* Other: 18F-Fluoride PET-CT ; CT calcium scoring ; 18F-FDG PET-CT


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: age > 18 written informed consent SVD defined on echocardiography by an alteration of bioprosthesis leaflets function with a mean transvalvular gradient > 20 mmHg and maximal velocity ≥ 3 m/s and effective orifice area ≤1.2 cm², and/or an aortic regurgitation more or equal to grade 2 on 4. Exclusion Criteria: Inability to give informed consent Pregnancy Concurrent antibiotherapy Certain infectious endocarditis Concurrent anti-inflammatory therapy, including corticosteroid therapy

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 18F-Fluoride PET-CT ; CT calcium scoring ; 18F-FDG PET-CT<br> | Other: 18F-Fluoride PET-CT ; CT calcium scoring ; 18F-FDG PET-CT<br>* 18F-Fluoride PET-CT CT calcium scoring 18F-FDG PET-CT<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 18F-Fluoride activity | 18F-Fluoride activity in valvular tissue will be determined by a tissue to bloodpool ratio of SUV (TBR). Patients will be divided in two groups : moderate SVD (EOA ≥ 0.8 and ≤ 1.2 cm²), and severe SVD (EOA ≤ 0.8 cm²), and TBR will be compared between the two groups, determined at time of inclusion. | The day of the inclusion | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| TBR in 18F-FDG | TBR in 18F-FDG will be compared between the two groups to analyze the inflammatory activity part in the SVD process | 6 months | 
| Both 18F-Fluoride and 18F-FDG TBR correlation | Both 18F-Fluoride and 18F-FDG TBR will be correlated with bioprosthesis calcium scoring and the following echocardiographic bioprosthesis function parameters : aortic regurgitation grade (none, trace, mild, moderate, severe) ; trans-valvular maximal velocity (m/s) ; mean trans-valvular gradient (mm Hg) ; EOA (cm²) ; visual echographic degenerescence score. | 6 months |