AMYLO-CARTESIAN Study :Prevalence and Post-surgical Outcomes of CARdiac Wild-type TransthyrEtin amyloidoSIs in Elderly Patients With Aortic steNosis Referred for Valvular Replacement.

Background: The prevalence of both senile cardiac amyloidosis (CA) and aortic stenosis (AS) markedly increases with age. Aortic stenosis increases left ventricular pressure overload. Cardiac deposits have been observed in AS and the amount of these deposits has been correlated to post-surgical outcome. As they are strong echocardiographic and cardiac MRI imaging similarities between CA and AS, the investigators hypothesized that the deposit observed in AS is transthyretin amyloid deposit. The investigators objective is to demonstrate that amyloid deposit is associated with poor outcomes following aortic stenosis surgical valve replacement. Materiel and methods: 180 patients with indication for surgical aortic valve replacement will be recruited prospectively and consecutively in 5 French centers. A replicative study will be performed in one Austrian center. Echocardiography, cardiac MRI and bone scintigraphy will be performed prior to surgery. During surgery, a basal LV septum biopsy will be collected for determination and quantification of interstitial deposits using specific staining which will be performed in a blind fashion. Clinical outcomes will be recorded during the hospitalization period following the surgery and at 1 year. Alive and re-hospitalization status will be determined. Patients will be classified according to the presence or not of amyloid deposits. Expected results and impact: This study will emphasize how pressure overload stress accelerates and magnifies amyloid deposition usually known to be related to cardiac aging process. It will develop reliable imaging tools and markers to detect cardiac amyloid deposition. Correlation between anatomopathologic analyses and the three different imaging technics will identify accurate imaging markers of CA. A risk stratification model based on amyloid deposits level for the clinical management of these patients will be created combining imaging and biological markers.