Correlation between coronary artery calcium score and aortic diameter in a high-risk population of elderly male hypertensive patients

Abstract

Background: Studies on the relationship between coronary artery calcium and aortic diameter are scarce. The aim of the current study was to evaluate the correlation between coronary artery calcium score (CACS) and maximal thoracic and abdominal aortic diameters in a population of elderly (>65 years) male hypertensive patients at high risk for coronary artery disease.

Patients and methods: From June 2012 to April 2013, we prospectively enrolled 393 male hypertensive patients older than 65 years of age who had no history of aortic aneurysm. Coronary artery calcium and maximal diameters of the ascending thoracic aorta (ATAmax), descending thoracic aorta (DTAmax), and abdominal aorta (AAmax) were measured using noncontrast computed tomography imaging. Aortic diameters are indexed to body surface area (BSA). Participants were divided into five groups according to CACS (0, 1-10, 10-100, 100-400, and >400).

Results: The mean ATAmax/BSA, DTAmax/BSA, and AAmax/BSA were 22.0±2.7, 16.3±1.9, and 13.0±2.9 mm, respectively. On multivariate analysis, ATAmax/BSA was associated independently with age, diabetes, and history of aortic valve replacement (all P<0.001). DTAmax/BSA was associated independently with age (P<0.001). However, there were no significant correlations between thoracic aorta diameter and CACS. In contrast, AAmax/BSA was associated independently with CACS as well as age and history of smoking (P=0.014, 0.003, and 0.019, respectively). Abdominal aortic aneurysm (>30 mm) was more prevalent in patients with a CACS of 400 or more compared with the others (14 vs. 3%, P<0.001).

Conclusion: CACS was associated with increased abdominal aorta diameter, but not with thoracic aorta diameter. Therefore, screening for an abdominal aortic aneurysm is warranted in patients with a high risk of coronary artery disease and a high CACS. However, the necessity for thoracic aortic aneurysm screening is not clear in these patients.

Fig. 1

Measurement of aortic diameters. (a) Ascending and descending thoracic aorta at the pulmonary artery bifurcation (PAB) and (b) abdominal aorta at the superior mesenteric artery (SMA) in the axial plane. The maximal diameter of ascending and descending thoracic aorta was remeasured in the sagittal (c) and coronal planes (d) using reconstructed images [10]. AA, abdominal aorta; ATA, ascending thoracic aorta; DTA, descending thoracic aorta.

Fig. 2

Correlation between aortic diameters and coronary artery calcium score: (a) ascending thoracic aorta, (b) descending thoracic aorta, and (c) abdominal aorta. ATA_max, maximal ascending thoracic aorta diameter; AA_max, maximal abdominal aorta diameter; BSA, body surface area; DTA_max, maximal descending thoracic aorta diameter.

Fig. 3

Prevalence of abdominal aortic (AA) aneurysm according to coronary artery calcium score (CACS).