Central aortic stiffness and its association with ascending aorta dilation in subjects with a bicuspid aortic valve

Abstract

BACKGROUND: Reduced elasticity and dilatation of the proximal aorta are highly prevalent in patients with bicuspid aortic valves (BAVs), even in the absence of valvular dysfunction. The aim of this study was to examine central aortic stiffness and its association with ascending aortic dilation in subjects with BAVs compared with controls.

METHODS: Fifty subjects with BAVs (39 men; mean age, 52 ± 14 years) without significant valve dysfunction and 50 age-matched and gender-matched controls with normal trileaflet aortic valves were studied. Aortic diameter was measured using two-dimensional echocardiography, and central hemodynamics were assessed simultaneously using radial artery tonometry. Subjects with BAVs were divided into two groups on the basis of the median value of the aortic diameter.

RESULTS: Subjects with BAVs had larger ascending aortic diameters (20.6 ± 4.0 vs 17.9 ± 2.4 mm/m(2), P < .001), higher augmentation indexes normalized for a heart rate of 75 beats/min (25.3 ± 9.7% vs 16.7 ± 8.6%, P < .001), higher pulse-wave velocities (7.8 ± 1.5 vs 7.2 ± 1.0 m/sec, P = .013), and lower pulse pressure amplification (1.24 ± 0.27 vs 1.35 ± 0.18, P = .022) than control subjects. The higher augmentation indexes were significant even in subjects with BAVs with relatively normal sized aortas. The diameter of the ascending aorta was correlated with augmentation index (r = 0.48, P < .001), pulse-wave velocity (r = 0.27, P = .063), and pulse pressure amplification (r = -0.46, P = .001) in subjects with BAVs.

CONCLUSION: Subjects with BAVs had stiffer central hemodynamics than controls with tricuspid aortic valves, even in the absence of significant aortic dilation. Central aortic stiffness was positively correlated with the degree of aortic dilation in subjects with BAV. Thus, the evaluation of central aortic stiffness could be useful for the early detection and risk stratification of aortopathy in subjects with BAVs.