Significance of the intima-media thickness of the thoracic aorta in patients with coronary atherosclerosis.

Background: The prevalence and clinical significance of atherosclerotic aortic disease have now been documented in a variety of patient populations by use of transesophageal echocardiography (TEE). There are many reports that atherosclerotic aortic plaques detected by TEE are a marker for coronary artery disease (CAD).

Hypothesis: The study was undertaken to evaluate the significance of the intima-media thickness (IMT) and formation of atherosclerotic plaques of the thoracic aorta (TA) in patients with CAD, especially in terms of a correlation between the IMT of the TA and the extent of coronary atherosclerosis.

Methods: The IMT of the TA was measured using TEE. The study population comprised 100 patients (68 men, mean age 59 years). The extent of coronary atherosclerosis was divided into four groups (0, 1, 2, 3) according to the number of coronary arteries narrowed > or = 50%.

Results: There was no significant difference in the IMT of the ascending TA according to the presence of significant (> 50% narrowed) coronary stenosis, but there was a significant difference in the IMT of the descending TA (1.39 vs. 1.88 mm, p = 0.005). There was a significant correlation between the extent of coronary atherosclerosis and the IMT of the ascending and descending TA (r = 0.24, p < 0.05; r = 0.352, p < 0.001, respectively). The plaques in the TA were seen in 7, 41, 52, and 65% of patients in Groups 0, 1, 2, and 3, respectively. Among atherosclerosis risk factors, hyperlipidemia was the only factor analyzed that affected the IMT of the descending TA (2.11 vs. 1.78 mm, p < 0.05).

Conclusion: The IMT of the TA correlates significantly with coronary atherosclerosis, and correlation of the descending TA IMT with coronary atherosclerosis is better than that of ascending TA IMT. Age is associated with coronary atherosclerosis, and TA IMT and hyperlipidemia are associated with descending TA IMT. Therefore, although TEE is not recommended for measuring TA IMT or for evaluating aortic plaques in patients with CAD, measurement of TA IMT as well as carotid artery IMT is very helpful for understanding the extent of coronary atherosclerosis.