Impact of Local Tissue Inflammation on Intramyocardial Conduction Pathways Post Percutaneous Valve : Evaluation by Positron Emission Tomography on Exploratory Cohort

Aortic valve stenosis is the most common valve disease leading to surgical or percutaneous intervention in Europe and North America. Percutaneous aortic valve replacement (TAVI) is currently recommended for the management of patients with symptomatic aortic stenosis and with high; very high operative risk of aortic valve replacement surgery or intermediate operative risk of aortic valve replacement surgery after a benefit-risk assessment by a heart team and operative contraindication to conventional aortic valve replacement surgery. These indications are supported by the 2017 European Cardiology guidelines.

This technique of percutaneous arterial valve implantation is most often performed via the femoral route, under local anesthesia, with placement of a prosthetic biological valve in the aortic position, impacting it into the patient's native aortic valve.

TAVI has been shown to be superior to medical treatment in patients with a aortic valve stenosis at very high operative risk of conventional aortic valve replacement surgery. However, the occurrence of atrioventricular conduction disorders (de novo left bundle branch block (LBBB) or complete AVB) remains the most frequent complication after TAVI. Therefore, the rate of pacemaker (PM) implantation after TAVI remains high, ranging from 2% to 51%, with an average rate of 13%.

Pacemaker implantation has several deleterious effects (increased hospitalization time, desynchronization of the left ventricle by permanent right ventricular pacing, exposure of the patient to procedural complications of pacemaker placement, and possible increase in the final cost to society of the initial hospitalization.

Not all patients who received a pacemaker post TAVI implantation use their PM. The rate of Pacemaker dependency and therefore of patients who actually use their pacemaker is approximately 33-36% at 1 year after percutaneous valve implantation.

In view of all the potentially deleterious consequences of post TAVI pacemaker implantation, it is therefore necessary to know which patients really justify pacemaker implantation after percutaneous valve implantation.

The purpose of this study is to investigate diagnostic imaging criteria that may be predictive of the occurrence of intramyocardial conduction disorders post TAVI implantation. Although some patients present only transient conductive disturbances, the impact of tissue inflammation of the intramyocardial conduction pathways after TAVI remains to be understood.


Eligibility Criteria:
Inclusion Criteria:

* Major patient (\>18 years of age);
* Patient with aortic stenosis defined by aortic valve area ≤ 1cm2 (or indexed aortic valve area ≤ 0.6 cm2/m2 body surface area), OR transvalvular peak velocity ≥ 4 m/s OR transvalvular mean gradient ≥ 40 mmHg, as assessed by transthoracic echocardiography performed in a patient at rest;
* Symptomatic patient with: dyspnea ≥ New-York Heart Association (NYHA) stage 2 OR pathological stress test with onset of symptoms on exertion, blood pressure drop, or rhythm disorder on exertion OR Asymptomatic with Left Ventricular Ejection Fraction \< 50% ;
* Patient with vascular anatomy compatible with percutaneous femoral valve implantation;
* Patient affiliated to or benefiting from a health insurance plan;
* Patient who has provided free, informed and written consent.

Exclusion Criteria:

* Patient with a pacemaker or triple chamber defibrillator prior to TAVI implantation;
* Patient with a uni or bicuspid aortic valve;
* Patient with severe left ventricular dysfunction LVEF \< 30%;
* Patient with other significant valve disease : aortic insufficiency ≥ grade 3, mitral insufficiency ≥ grade 3 or tight mitral stenosis ;
* Patient with iliofemoral vascular anatomy preventing safe passage of the valve;
* Patient with a pre-existing bioprosthesis or mechanical prosthesis at TAVI in any position;
* Inability or refusal to consent;
* Pregnant or breastfeeding woman;
* Patient under judicial protection or family habilitation;
* Patient deprived of liberty by judicial or administrative decision, under guardianship or curatorship;
* Patient with life expectancy \< 12 months.