Abstract 555: Clinical Significance of Focal Contrast Enhancement in Patients With Acute Distal Aortic Intramural Hematoma
Background: Focal contrast enhancement (FCE) contained in the aortic intramural hematoma (IMH) on computed tomography (CT) is occasionally observed in acute distal IMH. As data are limited regarding its prevalence and prognosis, optimal treatment strategy needs to be established.
Methods and Results: A total of 107 patients (age, 63±11 years; 64.5% male) with acute distal IMH from the registry of acute aortic syndrome were enrolled; serial CT and clinical follow-up durations were 29±33 and 52±36 months. FCE was present in 42 patients (group 1, 39.3%), whereas the others showed no FCE (group 2). Except higher prevalence of hypertension in group 1 (78.6% vs. 56.9%, p= 0.022), there was no difference in baseline characteristics between groups. Maximal aortic diameter was not different, but group 1 showed thicker hematoma (12.3±3.6 vs. 10.1±4.1 mm, p= 0.006). In-hospital mortality was not different between groups. Localized aortic dissection (AD) developed in 13 patients (12%) with significantly higher incidence in group 1 (21.9% 9/41 vs. 3.0% 2/67, p= 0.002). FCE was the only variable associated with progression into AD (hazard ratio = 15.82 [1.95, 128.24], p= 0.006). The 7-year survival rates were not different (77.7±9.4% vs. 77.7±5.8%, p= 0.745). Patients with localized AD showed comparable survival compared to those without and only 1 patient needed an elective stenting.
Conclusions: FCE is frequently observed during acute stage of distal IMH and is associated with progression into typical AD. However, over-all prognosis is excellent and prophylactic surgical or endovascular intervention cannot be justified.