Measurement of central augmentation index by three different methods and techniques: Agreement among Arteriograph,...

Wave reflection at central arteries consists of a major component of left ventricular afterload. Central augmentation index (AIx) is the most widely used surrogate of wave reflection. Recent technological developments now provide the ability to obtain, non-invasively, aortic, or carotid pressure waves and measure AIx based on various algorithms of pulse wave analysis. The aim of this study was to compare AIx measurements performed by the Arteriograph, Complior, and Mobil-O-Graph apparatuses. Recordings by each device in randomized order were performed with 5-minute interval at 211 individuals (age 55.1 ± 14.1 years, 67.8% males) who underwent diagnostic cardiovascular assessment. All measurements were obtained at the supine position, and AIx was calculated using the formula AIx = 100 × (Augmentation pressure)/(Pulse Pressure). Bland-Altman analysis was performed. Mean difference (bias) ± one standard deviation of difference (with limits of agreement) of AIx between different devices was as follows: (a) Mobil-O-Graph vs Complior: -2.1 ± 14.8% (-31.1% to 26.9%), (b) Arteriograph vs Complior: 12.9 ± 14.6% (-15.7% to 41.5%), and (c) Mobil-O-Graph vs Arteriograph: -10.8 ± 16.9% (-43.9% to 22.3%). The three examined devices exerted significant differences in central AIx estimation which makes the three devices non-interchangeable for wave reflection assessment. However, the Mobil-O-Graph device showed the highest agreement (lowest bias) with the Complior system as regards to the AIx measurement.