Exploratory Study of Prognostic Factors in Aortic Dissection Type B: Role of Imaging (18F-FDG PET-Scan and Angioscan) and Biomarkers

Clinical outcomes of chronic type B aortic dissections are unknown, especially in case of false lumen expansion and risk of rupture. Data of literature give us some indications about prognosis. The 1-year survival rate is about 80%, but we deplore the 25% rate of mortality at 3 years despite follow-up.The only known predictive factors are the initial diameter of more than 4 cm and the persistence of a false lumen patent.However, actual means of follow-up do not allow to predict severe complications. The aim of the sudy is to propose a diagnostic and preventive strategy for the follow-up of chronic type B aortic dissections treated medically.

The primary objective is then to evaluate the prognostic role of 18-FDG-PET Scan in such patients in order to predict the risk of aortic diameter growth of more than 5 mm in 1 year and/or of an aortic dissections extension at 1 year. The secondary objectives are to evaluate the link between fibrosis biomarkers MMP et TIMP) and the results of imaging results (evolution of diameter and extension and results of PET-Scan imaging) Methods: 100 patients to be included in 3 years History of chronic type B aortic dissection, treated medically, evolving since more than 1 month and less than 5 years.

Expected results: Prognostic contribution of 18FDG-PET-Scan and biomarkers for the identification of patients at high risk of evolution. Elaboration of a decisional algorithm about follow-up modalities of chronic aortic dissections. Demonstration of a correlation between aortic diameter growth or aortic dissection extension and intensity of marker fixation with 18-FDG-PET-Scan.