Differences in the Area of Proximal and Distal Entry Tears at CT Angiography Predict Long-term Clinical Outcomes in Aortic Dissection

Purpose: To identify entry tear variables that are related to adverse clinical events by using CT angiography (CTA) performed during the subacute phase of aortic dissection.

Materials and methods: In this prospective study conducted from January 2000 to December 2013, participants with an aortic dissection with a patent false lumen and no comorbidities underwent CTA during the subacute phase. Participants were followed up for a survival analysis to assess the time to an adverse aortic event (AAE). The maximum aortic diameter (MAD), proximal and distal tear areas and difference between these areas, and partial false-lumen thrombosis were assessed by using Cox regression for adverse events.

Results: Seventy-two participants (mean age, 55 years ± 12 [standard deviation]; 55 men) were evaluated: 47 were surgically treated (type A aortic dissection) and 25 were medically treated (type B aortic dissection). Twenty-two participants had an AAE manifest during follow-up (9.22 years ± 5.78): There were 18 elective surgeries for aneurysmal degeneration, two emergent surgeries for acute aortic syndrome, and two aortic condition-related deaths. A categorical model composed of genetic aortic disease (GAD) (hazard ratio [HR], 3.4 [95% CI: 1.2, 9.9]; P = .02), MAD greater than 45 mm (HR, 6.1 [95% CI: 2.4, 15.8]; P < .001), and tear dominance (HR, 5.2 [95% CI: 2.1, 13]; P < .001), defined as an absolute tear area difference of greater than 1.2 cm², was used to stratify participants into three risk groups: low, without any risk factors (57% [41 of 72] and 7% [three of 41] had events); intermediate, with one risk factor (31% [22 of 72] and 50% [11 of 22] had events); and high, with two or more risk factors (13% [nine of 72] and 89% [eight of nine] had events; log rank P < .001).

Conclusion: Tear dominance demonstrated at CTA performed in the subacute phase of aortic dissection was related to long-term adverse events. Participants without GAD, dominant tears, or MAD greater than 45 mm had conditions that were safely managed with optimal medical treatment and imaging follow-up.Keywords: CT Angiography, Vascular, Aorta, Dissection Supplemental material is available for this article. © RSNA, 2021See also commentary by Fleischmann and Burris in this issue.