AORTA AND ILIAC ARTERIES
The incidence of atherosclerosis of the abdominal aorta and iliac arteries is common. Among 4002 middle-aged patients, the prevalence of subclinical atherosclerosis was 63%. The plaques were detected in the aorta (25%) and iliofemoral arteries (44%) 23. The subclinical disease was detected in 58%, with an intermediate or generalized disease in 36% of patients with low Framingham Heart Study (FHS) 10-year risk. This suggests the added value of US imaging for the diagnosis and prevention of atherosclerosis. A higher prevalence of atherosclerosis in the aorta was shown in another study69. In 261 patients subjected to dual-source CCTA 69.3% had aortic plaques, mostly at the distal part of the abdominal aorta. The plaques were characterized as mixed (43%), calcified (24%), and soft (2%). Mixed and calcified plaques were the most often present in the abdominal aorta and its branches. In another study, the authors found similar rates of atherosclerotic lesions in the abdominal aorta (68%) as well as in the iliac arteries (35.6%) among asymptomatic patients based on CCTA 7. The association with significant coronary artery stenosis was strongest for atherosclerotic lesions with stenosis ≥25%, especially in the abdominal aorta (aOR 16.39) and any common iliac artery (aOR 7.32). Rangel et al. examined the frequency of association of CAD with aortoiliac lesions during aortic arteriography performed after CA 11. They found that 46% of patients had atherosclerotic aortoiliac lesions, and the number of affected coronary arteries was directly related to the frequency and extent of aortoiliac lesions. The findings from another study showed that patients with CVD had a higher prevalence of abdominal aortic plaques compared to patients without CVD (37.3% vs 17%)70. Patients with the three-vessel disease had a higher prevalence of the plaques than patients with two- and one-vessel disease (44.7% vs 35% vs 27%). Thus, abdominal aortic plaques were an independent factor of CVD presence and severity. Plaques in the aortic arch along with atrial fibrillation and carotid atherosclerosis were shown to be important causes of peripheral emboli and iatrogenic stroke71.
Atherosclerosis of the thoracic aorta is also common (43.7%)72, especially in patients with significant CAD (75.9%) 5. Aortic plaque seen on transthoracic echocardiography has been correlated with a higher prevalence of CAD and the presence of significant angiographic coronary artery stenosis73. In addition, the lack of aortic plaque has also been shown to predict the absence of CAD 74. Moreover, plaques in ascending aorta are an independent factor of long-term neurologic events and mortality 75.