Severity of Peripheral Arterial Disease is Associated With Aortic Pressure Augmentation and Subendocardial Viability Ratio

Abstract

Peripheral arterial disease (PAD) is associated with increased cardiovascular mortality that correlates with peripheral perfusion impairment as assessed by the ankle-brachial arterial pressure index (ABI). Furthermore, PAD is associated with arterial stiffness and elevated aortic augmentation index (AIx). The purpose of this study was to investigate whether ABI impairment correlates with AIx and subendocardial viability ratio (SEVR), a measure of cardiac perfusion during diastole. AIx and SEVR were assessed by radial applanation tonometry in 65 patients with stable PAD (Rutherford stage I-III) at a tertiary referral center. AIx corrected for heart rate and SEVR were tested in a multivariate linear and logistic regression model to determine the association with ABI. Mean ABI was 0.8±0.2, AIx 31%±7%, and SEVR 141%±26%. Multiple linear regression with AIx as a dependent variable revealed that AIx was significantly negatively associated with ABI (β=-11.5; 95% confidence interval [CI], -18.6 to -4.5; P=.002). Other variables that were associated with AIx were diastolic blood pressure (β=0.2; 95% CI, 0.1-0.4; P<.001), height (β=-46.2; 95% CI, -62.9 to -29.4; P<.001), body mass index (β=-0.4; 95% CI, -0.8 to -0.1; P=.023), and smoking (β=3.6; 95% CI, 0.6-6.6; P=.019). Multiple regression with SEVR as a dependent variable showed a significant correlation with ABI (β=33.2; 95% CI, 2.3-64.1; P=.036). Severity of lower limb perfusion impairment is related to central aortic pressure augmentation and to subendocardial viability ratio. This may be a potential pathophysiologic link that impacts cardiac prognosis in patients with PAD.