Abstract 10933: Peripheral Augmentation Index is an Index of not Only Arterial Stiffness but Also Endothelial Function
Background: Recent studies have shown that the augmentation index (AI) is a predictor of cardiovascular complications. Endothelial dysfunction is the initial step in the pathogenesis of atherosclerosis, which associated with cardiovascular events. Endothelial function assessed by brachial artery flow-mediated vasodilation (FMD) can serve as an independent predictor of cardiovascular events. However, there is little information on the relationship between peripheral AI measured by peripheral arterial tonometry (PAT) and FMD in the human vasculature. We therefore investigated relationship between peripheral AI and FMD in the present study.
Methods: A total of 153 subjects (82 males and 71 females; age range, 22-89 years; mean age, 59±15 years), including 126 patients with cardiovascular diseases or risk factors of atherosclerosis and 27 healthy subjects were enrolled. A high-resolution linear array transducer (10-MHz) was coupled to computer-assisted analysis software (UNEXEF18G; UNEX Co, Nagoya, Japan) that used an automated edge detection system for measurement of brachial artery diameter response to reactive hyperemia and sublingual nitroglycerine in all subjects. Peripheral AI was measured using an Endo-PAT 2000 (Itamar Medical Ltd, Caesarea, Israel), which calculates reactive hyperemia index and peripheral AI automatically.
Results: Univariate regression analysis revealed that peripheral AI correlated with age (r=0.50, P<0.001), systolic blood pressure (r=0.37, P<0.001), diastolic blood pressure (r=0.28, P<0.001), smoking pack-year (r=0.19; P=0.02) and FMD (r=-0.35, P<0.001) as well as Framingham risk score (r=0.35, P<0.001), a cumulative cardiovascular risk index for heart attack. There was no significant correlation between peripheral AI and vascular response to nitroglycerine. Multivariate analysis revealed that age, sex, systolic blood pressure, FMD were independent predictors of peripheral AI.
Conclusion: These findings suggest that peripheral AI may be a maker of the grade of atherosclerosis and is an index of not only arterial stiffness but also endothelial function.
- © 2013 by American Heart Association, Inc.