Asymptomatic Aortic Stenosis: The Influence of the Systemic Vasculature on Exercise Time

Abstract

Changes in the peripheral vasculature occur in patients with aortic stenosis (AS). The aims of the present study were to characterize peripheral arterial waveforms and aortic pulsewave velocity (PWV) in patients with AS and to determine their relationship to exercise time. The study included 101 patients with a median age of 68 years (range, 27-84 years) with at least moderate AS. Patients underwent transthoracic echocardiography, an assessment of the radial artery waveform and PWV using a SphygmoCor device, and a treadmill exercise stress test. The mean brachial systolic blood pressure was 143 ± 23 mm Hg in patients with severe AS and 135 ± 15 mm Hg in patients with moderate AS (P = .04). The mean radial augmentation index was 102 ± 20% in patients with severe AS and 89 ± 16% in those with moderate AS (P < .001). The radial augmentation index was related to the effective valve orifice area (R = -0.45, P = .001), the peak transvalvular pressure difference (R = 0.33, P = .001), and the mean transvalvular pressure difference (R = 0.33, P = .001). On univariate analysis, exercise time was related to systemic arterial compliance (R = 0.312, P = .008) and PWV (R = -0.44, P < 0.001). On multivariate analysis, after adjusting for age, AS severity, and PWV, only age was a significant predictor of exercise time (β = -0.46; P = .006; 95% confidence interval, -15 to -3). In patients with asymptomatic moderate to severe AS, exercise capacity is influenced only by age, not by resting measures of aortic valve stenosis or aortic stiffness.