Prevalence and risk factors of aortic aneurysm in patients with chronic obstructive pulmonary disease

Patients with chronic obstructive pulmonary disease (COPD) manifest an excess of chronic co-morbidities and present a high prevalence of cardiovascular disease such as congestive heart failure and ischemic heart disease. Aortic aneurysm (AA) also shared the risks of those diseases and its rupture is an important cause of death. However, since AA progresses almost silently, the prevalence of AA in patients with COPD remains unclear. The aim of this study was to determine AA prevalence and risk factors in patients with COPD.

With computed tomography (CT) screening, we tested for AA in 231 COPD patients, and assessed emphysema by Goddard classification and aortic wall calcification in abdominal artery, respectively. We also evaluated that of thoracic artery using our original methods, which we assessed the extent of calcification in the thoracic artery as well as which defined as "aortic calcification index (ACI) in thoracic artery".

In 231 patients with COPD, 27 (11.7%) had AA determined by CT imaging and another 6 patients with previously diagnosed AA and a history of repaired operation (2.6%). In this total of 33 patients (AA group), the age of 95% confidence interval (CI) was 75.8 to 80.1 years and the prevalence of AA in patients aged 76 to 80 years was 26.8%. A low attenuation area and aortic wall calcification were more severe in the AA group than in the non-AA group, but forced expiratory volume in 1 second (FEV1) was not significantly different in those patients. The Goddard score of nine and ACI in the thoracic artery of 25.0% were determined to identify the most appropriate cut-off levels for discriminating between AA and non-AA groups.

Our analysis indicated that sizeable under-recognition of AA seems likely in COPD. Especially for patients with severe lung destruction and aortic calcification verifiable by chest CT, abdominal CT would be beneficial for detecting AA.