Medical therapy in type B aortic intramural hematoma is associated with a high failure rate

Objective Intramural hematoma (IMH) is on the spectrum of acute aortic syndrome, but optimal management is poorly understood. The aim of this study was to evaluate outcomes of patients with type B IMH (TBIMH) after best medical therapy (BMT) and to assess for risk factors associated with failure of BMT. Methods This is a single-institution retrospective chart review of all patients with TBIMH between January 2008 and December 2017. Failure of BMT was defined as any of the following end points: aortic rupture, aorta-related death, aortic enlargement to at least 55 mm or growth of >10 mm within 12 months, or need for surgical aortic intervention for failed BMT. Results We identified 92 patients, of whom 25 received emergent thoracic endovascular aortic repair; 67 patients were initially managed with BMT, and of these, 32 underwent thoracic endovascular aortic repair within 14 days for early BMT failure. Two additional patients had early BMT failure; one died of aortic rupture due to retrograde type A dissection, and one patient was advised to undergo repair but did not comply and was lost to follow-up. Fourteen patients (20.9%) received endovascular therapy for late failure of BMT after the initial hospitalization. Medical management was successful in 19 patients (28.4%), although 5 patients had aortic enlargement but below the threshold for elective repair (maximal aortic diameter of 55 mm). On univariate analysis, presenting IMH thickness and growth of IMH thickness were risk factors for BMT failure. On multivariate analysis, presenting IMH thickness was the sole predictive risk factor for medical therapy failure (odds ratio, 1.083; 95% confidence interval, 1.021-1.149; P = .008), with an odds ratio of 6.810 (95% confidence interval, 1.921-24.146; P = .002) with a presenting IMH thickness of ≥8.0 mm, which was the calculated IMH thickness cutoff value with highest sensitivity and specificity to predict failure of BMT (area under the receiver operating characteristic curve = 0.795; P = .001; J = 0.62). Conclusions BMT for TBIMH is associated with a high failure rate and need for interventions. IMH thickness on admission is the most reliable factor to predict failure of BMT.