The Effect of Subclinical Leaflet Thrombosis and Prosthesis Type on Transcatheter Aortic Valve Degeneration (POPular PET TAVI)

Study Overview
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Brief Summary
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A multicentre cross-sectional cohort study to assess the difference in bioprosthetic micro-calcification activity, detected with 18F-NaF PET-CT, as early marker of transcatheter valve degeneration, between patients with vs. without subclinical leaflet thrombosis at five years after TAVI; and between patients with intra-annular vs. supra-annular TAVI prostheses.

Detailed Description
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Subclinical leaflet thrombosis (SCLT) occurs frequently after TAVI and has been associated with an increased risk of valve dysfunction. A persistent form of SCLT may lead to thrombus calcification and valve degeneration and increase the long-term risk of symptomatic bioprosthetic valve deterioration. Intra-annular in comparison to supra-annular TAVI valves have been associated with a higher risk of SCLT and valve thrombosis. Intra-annular valves may create larger neo-sinuses and flow stagnation zones, which favour local thrombogenicity. Whether different prosthesis types lead to a higher degree of transcatheter valve calcification and degeneration is currently unexplored. Recently, 18F-sodium fluoride (18F-NaF) positron emission tomography (PET) has emerged as a non-invasive modality capable of imaging bioprosthetic micro-calcification activity, which is an early and powerful predictor of valvular dysfunction and eventually valve failure. In the present study, we investigate for the first time, the differences in quantified bioprosthetic micro-calcification activity with 18F-NaF PET as early marker of transcatheter valve degeneration between patients with and without SCLT and between patients with intra-annular vs. supra-annular prostheses at five years after TAVI.

Official Title
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The Effect of Subclinical Leaflet Thrombosis and Prosthesis Type on Transcatheter Aortic Valve Degeneration

Conditions
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Aortic Valve Stenosis

Intervention / Treatment
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* Diagnostic Test: 18F-sodium fluoride Positron Emission Tomography (18F-NaF PET), Cardiac Computed Tomography (CT), Transthoracic Echocardiography (TTE)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Successful TAVI with Sapien or CoreValve Evolut prosthesis about 5 years ago Able to undergo hybrid 18F-NaF PET-CT imaging and transthoracic echocardiography Written informed consent Exclusion Criteria: Temporary or chronic oral anticoagulation use after TAVI Known severe renal insufficiency Known severe paravalvular regurgitation History of valve-in-valve procedure History of aortic valve re-intervention (including percutaneous paravalvular leak closure)

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Intra-annular<br>Patients with an intra-annular Sapien TAVI prosthesis | Diagnostic Test: 18F-sodium fluoride Positron Emission Tomography (18F-NaF PET), Cardiac Computed Tomography (CT), Transthoracic Echocardiography (TTE)<br>* Patients undergo a hybrid 18F-NaF-PET CT scan and TTE at five years after TAVI<br>|
| Supra-annular<br>Patients with a supra-annular CoreValve Evolut TAVI prosthesis | Diagnostic Test: 18F-sodium fluoride Positron Emission Tomography (18F-NaF PET), Cardiac Computed Tomography (CT), Transthoracic Echocardiography (TTE)<br>* Patients undergo a hybrid 18F-NaF-PET CT scan and TTE at five years after TAVI<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Quantified bioprosthetic micro-calcification activity | 18F-NaF uptake originating from any of the bioprosthetic valve leaflets assessed with 18F-NaF Positron Emission Tomography | 5 years after TAVI | 
| Subclinical Leaflet Thrombosis | Hypo Attenuated Leaflet Thickening (HALT) assessed with cardiac Computed Tomography | 5 years after TAVI | 
| Valve dysfunction | Transvalvular gradients assessed with transthoracic echocardiography | 5 years after TAVI | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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TAVI, TAVR, Subclinical Leaflet Thrombosis, Bioprosthetic Valve Deterioration, Intra-annular, Supra-annular