Validity of a Novel Wristband Tonometer for Measuring Central Hemodynamics and Augmentation Index

Abstract BACKGROUND Central hemodynamic and augmentation indices are independent predictors of cardiovascular events and all-cause mortality that can be estimated noninvasively by pulse wave analysis. The purpose of this study was to assess the reliability and validity of a newly engineered wristband tonometer for acquiring radial artery pressure waveforms. METHODS Radial artery pulse pressure waveforms were evaluated with an established pencil-type and a novel wristband tonometer in 31 participants (aged 30.2±9.5 years) resting in a supine position. Pulse wave analysis was executed using the same validated generalized transfer function (SphygmoCor) for both tonometers. RESULTS A significant difference in time to data acquisition between tonometers was observed (−70.2±147.7 s; P < 0.05; wristband faster). The wristband tonometer had significantly lower within-subject coefficients of variation (CV) compared with the pencil-type tonometer in aortic pulse wave height (−2.67% ± 5.51%; P < 0.05) and time to reflection (−2.26% ± 6.16%; P < 0.01). No other differences in CV were observed. Slight but statistically significant mean differences between tonometers were observed in aortic systolic blood pressure (ASBP; 0.43±1.08mm Hg; P < 0.05; wristband lower), aortic pulse pressure (APP; 0.43±0.96mm Hg; P < 0.05; wristband lower), and round-trip travel time of the reflected pressure wave (Δtp; 3.58±12.86ms; P < 0.05; wristband higher). However, ASBP, APP, and Δtp measurements were highly correlated (r = 0.9970, r = 0.9953, and r = 0.8838, respectively, P