Tissue PET) Vascular metabolic imaging and peripheral plasma biomarkers in the evolution of chronic aortic dissections

Aims Despite adequate medical management, dissection of the descending aorta (type B) may develop complications, including aneurysmal progression and eventually rupture. Partial false lumen thrombosis has been identified as a marker of adverse evolution in chronic dissection. The aim of this study was to test the ability of complementary information, provided by 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) and peripheral biomarkers, to add pathophysiological significance and a prognostic value to morphological data. Methods and results We explored serial aortic 18F-FDG uptake by PET/CT imaging and plasma biomarkers in a series of 23 patients with type B dissection to predict complications from initial data and to investigate potential associations with aneurysmal expansion during follow-up. Complications occurred in 17 patients. Acute initial characteristics associated with complications were male gender ( P = 0.021), arterial hypertension ( P = 0.040), aortic dissection diameter ( P = 0.0086), partial thrombosis of the false channel ( P = 0.0046), and enhanced focal 18F-FDG uptake ( P = 0.045). During follow-up (mean 16.7 ± 8.0 months), aneurysmal expansion was associated with false lumen morphology ( P <0.0001), quantitative 18F-FDG uptake, ( P = 0.0029), elevated plasma concentrations of biomarkers of platelets (P-selectin, P = 0.0009) and thrombin activation (TAT complexes, P = 0.0075), and fibrinolysis (PAP complexes, P < 0.0001; D-dimers, P = 0.0006). Plasma markers of coagulation and fibrinolysis were related to false channel morphology, suggesting that thrombus biological dynamics may drive progressive expansion of type B dissections. Conclusion Enhanced FDG uptake may be considered as a complementary imaging marker associated with secondary complications in type B dissections. During follow-up, aneurysmal progression is related to PET/CT and biomarkers of thrombus renewal and lysis.