Assessment of aortic stiffness by transesophageal echocardiography

Aortic stiffness, often measured by the carotid/femoral pulse-wave velocity (PWV) method, has become an attractive predictor for cardiovascular (CV) risk. Although noninvasive, PWV requires additional equipment and training. Aortic diameters measured at transesophageal echocardiography (TEE) provide high spatial resolution images as an alternative to PWV, and permit a more routine assessment of aortic stiffness. The purpose of this study was to measure aortic diameters at TEE, calculate aortic stiffness and compare these data to those of the more established PWV as estimates of CV risk and survival.

Systolic and diastolic aortic dimensions were measured retrospectively in 500 consecutive patients who had a clinically indicated TEE. Aortic compliance, distensibility, and stiffness index were calculated using the aortic diameters and corrected brachial cuff blood pressures (BP).

Compliance significantly related to age and mean BP (both P < 0.0001) and nearly significantly to chronic renal disease (P = 0.064). The results for distensibility and stiffness index were similar. When analyzed by Kaplan-Meier curves, all stiffness tertiles were significantly predictive of 4.5- to 7.5-year survival. These calculated values behaved similar to those of PWV reported in the literature.

This study showed that in patients undergoing routine TEE, aortic stiffness can be readily measured and that the derived values offer relationships comparable to those of PWV, including survival prediction. The method may also find use in assessing aortic stiffness in the TEE evaluation of patients with a bicuspid aortic valve or in preparation for transcatheter aortic valve replacement.