Carotid Intima-media Thickness in Patients with Abdominal Aortic Aneurysms

Objective

The contribution of atherosclerosis to the development of Abdominal Aortic Aneurysms (AAA) is still controversial. Ultrasound scans can detect intima-media thickening of the carotid arteries as an early sign of atherosclerosis. The aim of this study was to investigate whether patients with Abdominal Aortic Aneurysms (AAAs) have thickened carotid IMT as patients with atherosclerotic peripheral arterial disease (PAD).

Methods

With high-resolution B-mode ultrasonography, the intima-media thickness (IMT) in the carotid arteries (right and left common carotid artery) was measured in AAA patients and compared with that of age and sex-matched patients with atherosclerotic peripheral arterial disease (PAD). A third group of healthy age and sex- matched control subjects were included for comparison. The corresponding carotid artery lumen was also determined in all groups. Comparison of the three groups was made by ANOVA.

Results

Fifty-eight AAA patients and 69% were men (mean age of 72.3 years) were studied. Aged and sex-matched groups comprised of 111 PAD patients and 71 healthy. The mean carotid IMT was highest in PAD patients (1.036±0.18mm). The values of controls and AAA patients were similar and significantly lower than that of atherosclerotic patients (0.875±0.11mm and 0.812±0.53mm respectively, both p<0.005 vs. PAD). Narrowing of the corresponding lumen was found in PAD patients compared with that of AAA patients, but no difference can be seen between healthy subjects and AAA patients. The mean carotid IMT was greater in men (P<0.05) in all studied groups, but no similar gender specificity was found in the lumen diameter.

Conclusions

This study shows that the carotid artery IMT of AAA patients is similar to healthy subjects, but not as thick as patients with atherosclerotic disease. As carotid (IMT) is a surrogate marker of atherosclerosis, the findings support the notion that the formation of AAA may not be fully atherosclerosis-dependent. Gender may be a confounding factor for carotid intima-media thickening.

Keywords: Carotid, IMT, Abdominal aortic aneurysm