Augmentation Index Is Elevated in Aortic Aneurysm and Dissection

Background. The augmentation index, the ratio of the ejection pressure from the heart to the reflection pressure from the arterial system, has recently been recognized as one of the indexes of left ventricular afterload. We studied it in patients with aortic aneurysm and dissection, using carotid artery diameter waveform obtained from an echo-tracking system. Methods. Forty-six patients were divided into the following three groups based on pathology: group A, 21 patients with thoracic aortic aneurysm; group B, 15 patients with chronic aortic dissection; and group C, 10 patients without any aortic diseases. Using an echo-tracking system on the carotid artery, we measured stiffness parameter beta, arterial compliance, and the augmentation index. Results. There was no significant difference in stiffness parameter beta and arterial compliance among the three groups. The augmentation index was significantly higher in groups A and B than group C (22 +/- 10%, 22 +/- 13% vs 8 +/- 17%; p = 0.012). Female (p = 0.028) and heart rate (p = 0.005) were significantly associated with the augmentation index and the significance of aortic diseases was marginal (p = 0.056). Conclusions. The carotid augmentation index is elevated in patients with aortic aneurysm and dissection.