Carotid Intima-Media Thickness Provides Evidence that Ascending Aortic Aneurysm Protects against Systemic Atherosclerosis

Previous evaluation of total aortic calcium score suggests that mutations promoting ascending aortic aneurysm development may protect against atherosclerosis. However, calcium score is a late indicator of atherosclerosis. We evaluated carotid intima-media thickness (IMT), an earlier marker, to assess the degree of atherosclerosis in ascending aortic aneurysm patients compared to controls. Images of right and left common carotid arteries were obtained in 52 patients with ascending aortic aneurysms and 29 controls using a Sonosite MicroMaxx ultrasound. IMT was measured with Sonosite Sonocalc IMT software, a computer-based algorithm with manual override. Six IMT measurements were obtained for each patient (right and left proximal, mid and distal common carotid artery) by a single observer and averaged. A multiple linear regression analysis was applied to test for an association between aneurysm and IMT. Patients with ascending aortic aneurysms had 0.131-mm lower carotid IMT values than controls (p = 0.0002), independent of risk factors for atherosclerosis (age, BMI, gender, family history, smoking, dyslipidemia, race, diabetes and hypertension). The average IMT was 0.50 +/- 0.13 mm for individuals with aneurysm and 0.60 +/- 0.11 mm for controls. Age increased the IMT by 0.005 mm per year (p = 0.0003). BMI, male gender, positive family history, dyslipidemia, diabetes and hypertension also increased the IMT, but did not reach statistical significance. This investigation provides further evidence that ascending aortic aneurysm provides protection against the development of atherosclerosis, supporting the hypothesis that proaneurysmal genetic mutations may also be antiatherogenic. Copyright (c) 2012 S. Karger AG, Basel