Risk factors for mortality and failure of conservative treatment after aortic type B dissection

Despite medical treatment, one third of patients with uncomplicated type B aortic dissections experience severe late complications. The aim of this study was to identify patients at high risk of mortality during follow-up.

A total of 183 patients with acute Stanford type B dissection were treated in one of the university hospitals (Aachen [Germany], Maastricht [The Netherlands], and Innsbruck [Austria]) between 1997 and 2010. Records indicated that 120 patients were treated conservatively. Of these patients, 16 were lost to follow-up. The maximum diameter, extent of the dissection, and patency of the side branches were determined from computed tomography angiography data. Survival and treatment failure were analyzed by univariate and multivariate Cox regression analysis. The univariate analysis investigated the influence of aortic diameter (≥41 vs <41 mm) on survival, and the multivariate analysis investigated the influence of aortic diameter, age, sex, and surgery on survival.

During the follow-up period, the initial treatment was converted to surgical treatment in 21 patients (20.2%). Sixteen of the 104 patients (15.4%) died after a mean of 845.5±805.9 days. The mean maximum aortic transversal diameter at admission was 41.2±8.7 mm. The multivariate analysis identified aortic diameter (P=.004; hazard ratio, 1.07) and age (P=.038; hazard ratio, 1.05) as risk factors that significantly reduce survival.

Our study revealed both early aortic dilatation and older age as risk factors for increased mortality after conservative treatment of type B dissection.