Introduction:
Although acute type B aortic intramural hematoma (B-IMH) is a variant of acute aortic syndrome having similar clinical demographics to type B classic aortic dissection (B-AD), early clinical course including acute complications are not well investigated. The purpose of this study was to investigate early clinical course and acute complications of B-IMH in comparison with that of B-AD.
Methods:
Clinical features and early clinical course including acute complications were retrospectively analyzed in 270 B-IMH and 177 B-AD consecutive patients who were admitted to our hospital between 1991 and 2020. Acute complications were defined as rupture, impending rupture, re-dissection, and visceral and leg ischemia.
Results:
As compared with B-AD, B-IMH presented at older age (72±11 vs 62±15 years; p<0.001), predominantly in females (37% vs 25%). During in-hospital courses, limb ischemia and mesenteric ischemia were less common in patients with B-IMH than those with B-AD (0.4% versus 5.1%, p=0.003, 0.4% versus 2.8%, p=0.03; respectively). In contrast, spinal ischemia was more common in B-IMH patients (2.4% versus 0.6%, p=0.05). Aortic rupture and impending rupture were comparable between B-IMH and B-AD patients (5.9% versus 7.3%. p=0.28). Besides, re-dissection was also comparable between two groups (2.2% versus 5.1%, p=0.06). As a result, prevalence of acute complications was significantly lower in patients with B-IMH (8.8% versus 17%, p=0.008). In-hospital mortality rate in B-IMH was significantly lower than that in B-AD (0.4% versus 9.0%, p<0.001).
Conclusions:
Although patients with B-IMH had lower in-hospital mortality rates than patients with B-AD, significant portion of B-IMH patients had fatal complications including spinal ischemia or aortic rupture. Patients with B-IMH should be carefully observed as well as patients with B-AD patients.
A frequently overlooked cause of chest pain: Acute aortic intramural hematoma
