Effect of Hypertension on Aortic Root Size and Prevalence of Aortic Regurgitation

Abstract

Although early reports suggested that hypertension predisposed to aortic root enlargement and consequent aortic regurgitation, more recent pathological and M-mode echocardiographic studies have not found an association between hypertension and aortic enlargement when age is considered. These discrepancies may partially reflect methodological shortcomings in the accuracy and reproducibility of aortic and blood pressure measurements. Therefore, we measured two-dimensional echocardiographic diameters of the aortic root at four locations and compared findings with ambulatory and resting blood pressures and measures of body size in 110 normotensive and 110 hypertensive men and women matched for age and sex. Aortic diameters at the anulus (2.41±0.29 versus 2.34±0.24 cm, P =.06) and sinuses (3.47±0.44 versus 3.37±0.36 cm, P =.08) were marginally higher, whereas diameters at the supra-aortic ridge (2.94±0.38 versus 2.81±0.32 cm, P <.01) and ascending aorta (3.26±0.45 versus 3.11±0.32 cm, P <.01) were significantly increased in hypertensive subjects. Aortic diameters increased with increasing quartiles of diastolic and systolic pressures, particularly at the supra-aortic ridge and ascending aorta. In multivariate analyses, blood pressure remained an independent determinant of distal aortic diameters after body size and age were considered. Aortic regurgitation was seen in 5 normotensive and 7 hypertensive subjects and did not differ in severity. Thus, hypertension is associated with a slight increase in aortic root size, most notably of the supra-aortic ridge and proximal ascending aorta. Although dilatation at the commissural attachment might be expected to predispose to an increase in aortic regurgitation, we did not detect such a difference in this population of healthy, asymptomatic individuals.