Influence of clinical presentation on the outcome of acute B aortic dissection: evidences from IRAD

In-hospital outcome of acute type B dissection (ABAD) is strongly related to preoperative aortic conditions. In order to clarify the influence of the clinical presentation on the outcome, we analyzed the patients of the International Registry of Acute Aortic Dissection (IRAD). All patients affected by complicated ABAD, enrolled in the IRAD from 1996-2004, were included. Complications were defined as the presence of shock, periaortic hematoma, spinal cord ischemia, preoperative mesenteric ischemia/infarction, acute renal failure, limb ischemia, recurrent pain, refractory pain or refractory hypertension (group I). All other patients were categorized as uncomplicated (group II). A comprehensive analysis was performed of all clinical variables in relation to in-hospital outcome.

The overall in-hospital mortality among 550 patients was 12.4%. Mortality in group I (250 patients) was 20.0 %, compared to 6.1% in group II (300 patients) (P<0.001). Univariate predictors of ABAD complications were Marfan syndrome, abrupt onset of pain, migrating pain, any focal neurological deficits, need for higher number of diagnostic examinations and use of magnetic resonance and/or aortogram, abdominal vessels involvement at aortogram, larger descending aortic diameter, especially >6 cm, pleural effusion, and widened mediastinum on chest X-ray. Univariate predictors of a non complicated status were normal chest X-ray and medical management. In group I, in-hospital mortality following surgical and endovascular intervention were 28.6% and 10.1% (P=0.006), respectively. Independent predictors of overall in-hospital mortality included age >70 years, female gender, ECG showing ischemia, preoperative acute renal failure, preoperative limb ischemia, periaortic hematoma, and surgical management. The only independent variable protective for mortality was magnetic resonance as diagnostic test.

ABAD is a heterogeneous disease that produces dissimilar clinical subsets, each of which can have specific clinical signs, management and in-hospital results. In IRAD ABAD uncomplicated patients, medical therapy was associated with best hospital outcome, while endovascular interventions were associated with better results than surgery when invasive treatments were required. Although selection bias may be possible, and irrespective of treatments, knowledge of significant risk factors for mortality may contribute to a better management and a more defined risk-assessment in patients affected by ABAD.