Comparison of augmentation index derived from multiple devices

One of the most commonly evaluated features of the arterial pressure waveforms is augmentation index (AI). Multiple devices have been developed and marketed that measure AI at peripheral arteries. Currently, it is not known if and how these measures of AI are related. Aortic and radial AI (using SphygmoCor), radial AI (Omron), and finger AI (Itamar) were measured in 40 apparently healthy subjects. All the AI values were correlated with each other with Pearson r-values ranging from 0.78 to 0.94. The coefficients of variation ranged from 3.4 to 20.0%. We concluded that even though the absolute values derived by each technique were different, there were high and significant correlations between AI values.