Usefulness of Computed Tomography Parameters in Predicting the Clinical Outcomes of Acute Aortic Dissection

Abstract

Background : Acute aortic dissection is a potentially life-threatening condition among patients presenting with chest pain to emergency department. Without a prompt diagnosis and treatment, it carries high mortality and morbidity. Computed tomography (CT) of thorax and abdomen is one of the commonly used non-invasive investigation modalities for diagnosis of acute aortic dissection. Apart from making a diagnosis, there are a number of parameters in the CT images that may be helpful in providing prognostic information. In this study, prognostic values of these parameters in predicting both short term and intermediate term clinical outcomes of acute aortic dissection will be evaluated. Methods : This is a retrospective observational study involving 70 patients with diagnosis of acute aortic dissection recruited between January 2004 and December 2009 in North District Hospital in Hong Kong. Results : The mean age of these patients was 61 years old and 87% of them were male. The in-hospital mortality was 18.6% (13/70). The 30-day mortality was 24.3% (17/70). The mean maximal aortic diameter of all patients was 4.60 cm ± 1 cm. The mean maximal aortic diameter of the survived group was 4.49 cm ± 0.93 cm, whereas it was 5.22 cm ± 1.22 cm in the deceased group (p ¼ 0.032). Furthermore, the presence of patent false lumen (p ¼ 0.011) in the initial scan was also more prevalent in the deceased group. By univariate logistic regression analysis, the type of aortic dissection (OR 11.0, p ¼ 0.003), the larger maximal aortic diameter (OR 2.0, p ¼ 0.041), and also patent false lumen (OR 6.6, p ¼ 0.021) in the initial imaging were adverse prognostic indicators for in-hospital mortality. However, they were not found to be independent predictors with multivariable analysis. Conclusion : In addition to establishing the diagnosis of acute aortic dissection, the type of aortic dissection, the maximal aortic diameter, and also the patency of false lumen derived from contrast CT thorax and abdomen may also provide prognostic information with regards to in-hospital and 30-day mortality. Whether this information will lead to better clinical outcomes by earlier intervention requires further studies for con fi rmation.