Factors associated with in-hospital mortality in patients with acute aortic syndrome involving the ascending aorta

Background Aortic intramural hematoma (IMH), a variant form of classic dissection (AD), is an increasingly recognized and potentially fatal entity of acute aortic syndrome (AAS). We sought to assess the real impact of increased recognition of IMH on mortality of AAS involving the ascending aorta. Methods We evaluated 186 consecutive patients with AAS involving the ascending aorta (57.0 ± 13.5 years, 95 females) admitted between January 1993 and March 2003. Results Final diagnosis was AD in 135 patients and IMH in 51 (27%). Patients with AD were younger (54.0 ± 13 vs. 65.6 ± 10.7 years, p < 0.05) and surgery was more frequently performed (82% vs. 31%, p < 0.001). Overall in-hospital mortality was 16% (30/186); both total mortality (19% vs. 8%, p = 0.059) and mortality without surgery (71% vs. 9%, p < 0.001) was higher in AD. Logistic regression identified the following presenting variables as predictors of mortality: AD (OR 53.0; 95% CI, 6.6–425.4; p < 0.001), confusion/coma (OR 20.1; 95% CI, 3.8–107.8; p < 0.001), tamponade (OR 5.3; 95% CI, 1.2–24.3; p = 0.031), heart failure (OR 8.1; 95% CI, 1.1–61.0; p = 0.043), and medical treatment only (OR 17.6; 95% CI, 4.6–67.6, p < 0.001). Tamponade was more prevalent in IMH (25% vs. 11%, p = 0.038), and was a predictor of higher mortality in both groups. Conclusion IMH comprises of significant proportion of AAS involving the ascending aorta and is an independent variable associated with lower mortality despite lower frequency of surgery. Treatment option including optimal timing of surgery can be individualized based on underlying disease entity of AAS and some clinical features at the initial presentation.