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

Nantes University Hospital25 enrolled

Overview

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.

Study Type

INTERVENTIONAL

Allocation

Purpose

OTHER

Masking

NONE

Enrollment

Conditions

Aortic Bioprosthesis Structural Valve Dysfunction

Interventions

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

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

Outcomes

Primary Outcomes

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.

Time frame: The day of the inclusion

Secondary Outcomes

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

Time frame: 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.