Peripheral "oscillatory" compliance is associated with aortic augmentation index

The augmentation index (AIx) and "oscillatory" compliance (C-2) are wave contour analysis parameters for the central aorta (P-ao) and radial artery pressure wave (P-rad)(x) respectively. Both are sensitive to cardiovascular risk factors such as aging, hypertension, and diabetes and have been proposed as prognostic markers for cardiovascular disease. In this work, we studied the relation between both. We first calculated P-rad corresponding to a typical aortic A-type (AIx >0.15) and C-type wave (AIx 0.036 versus 0.071 +/-0.042). C-2 is related to AIx and reflects, at least in part, hemodynamic changes affecting central aortic pressure. Nevertheless, given the model assumptions and computational steps associated with calculating C-2, AIX could be a more appropriate parameter to use in the clinical setting because it is determined directly from the pressure wave contour.