Background: The long-term clinical course of patients with type B aortic intramural hematoma (IMH) and predictors for progression remains unknown. The difference of aortic pathology may have a different impact on clinical course compared with classic aortic dissection (AD). The purpose of this study was to investigate long-term clinical course and predictors of progression in patients with type B IMH.
Methods and results: Clinical data were compared retrospectively between 53 patients with acute type B IMH (IMH group) and 57 patients with acute type B AD (AD group). All patients were treated initially with medical therapy. Two patients in IMH group and 14 patients in AD group underwent surgical repair because of aortic enlargement. The in-hospital mortality rate in IMH group was significantly lower than that in AD group (0% and 14%, P=0.006). Mean follow-up periods were 53+/-43 months, which revealed 3 and 5 late deaths, respectively. Eleven patients with IMH showed progression (development of aortic dissection or aortic enlargement) in follow-up imaging study. The actuarial survival rates in IMH group were 100%, 97%, and 97% at 1, 2, and 5 years, which were significantly higher than those in AD group (83%, 79%, and 79%) (P=0.009). Multivariate analysis identified age >70 years and new appearance of an ulcerlike projection as the strongest predictors of progression in patients with IMH.
Conclusions: Patients with type B IMH have better long-term prognosis than patients with AD. Older age and appearance of an ulcerlike projection are predictive for progression in patients with type B IMH.