Aortic Growth and Development of Partial False Lumen Thrombosis are Associated with Late Adverse Events in Type B Aortic Dissection

Abstract Objective Patients with medically treated type B aortic dissection (TBAD) remain at significant risk for late adverse events (LAEs). We hypothesize that not only initial morphological features, but also their change over time at follow-up are associated with LAEs. Material and Methods Baseline and 188 follow-up CT scans with a median follow-up time of 4 years (range 10 days to 12.7 years) of 47 patients with acute uncomplicated TBAD were retrospectively reviewed. Morphologic features (n=8) were quantified at baseline and each follow-up. Medical records were reviewed for LAEs, which were defined according to current guidelines. To assess the effects of changes of morphological features over time, the linear mixed effects models were combined with Cox proportional hazards regression for the time-to-event outcome using a joint modeling approach. Results LAE occurred in 21 of 47 patients after a median time of 6.6 (95% CI: 5.1 – 11.2) years. Among the 8 investigated morphologic features, the following 3 features showed strong association with LAE: Increase of partial false lumen thrombosis area (HR=1.39 [1.18-1.66] per cm2 increase; p Conclusions In medically treated type B aortic dissection, increase in aortic diameter, new or increased partial false lumen thrombosis area and increase of circumferential extent of false lumen are strongly associated with LAEs.