Ascending Aortic Dimensions in Hypertensive Subjects: Reference Values for Two-Dimensional Echocardiography

Abstract

Background: Aortic dilation is an independent predictor of cardiovascular disease. The association between hypertension and aortic dilation is still controversial. Also, most previous research has investigated this relationship regarding only the aortic root, and no information is available for the ascending aorta (AscAo).

Methods: To assess AscAo dimensions in hypertensive patients, 1,027 patients with hypertension and 1,002 healthy volunteers were prospectively enrolled. Aortic diameters at four levels were measured using the leading edge-to-leading edge convention at end-diastole: the sinuses of Valsalva, sinotubular junction (STJ), AscAo, and aortic arch (AoArch), using two-dimensional echocardiography.

Results: All four diameters were significantly larger in hypertensive patients than in control subjects, with positive correlations with age, body size, and male sex. On multivariate analysis, gender and body surface area were independently associated with aortic diameters. The general linear model showed that after adjusting for age, sex, and body surface area, hypertension was positively associated (P < .01) with higher aortic diameter at every level. Hypertension was associated with increases of 1.7 mm (95% CI, 1.2-2.1 mm) at the sinuses of Valsalva, 4.1 mm (95% CI, 3.6-4.6 mm) at the STJ, 1.6 mm (95% CI, 1.1-2.1 mm) at the AscAo, and 2.2 mm (95% CI, 1.7-2.6 mm) at the AoArch. On the basis of nomograms, an abnormally high prevalence of aortic dilation in hypertensive patients was observed for the STJ (14%) and the AoArch (7%).

Conclusions: Systematic analysis of the AscAo in hypertensive patients showed that, together with age, sex, and body surface area, hypertension is an independent factor associated with increases in all four aortic diameters and that aortic dilation occurred more frequently at the level of the STJ and AoArch.

Keywords: Aorta; Hypertension; Reference values; Thoracic aortic diameters; Two-dimensional transthoracic echocardiography.