P.022 Validity of the Tensioclinic Device to Measure Arterial Stiffness in Patients on Hemodialysis

Abstract

Assessment of arterial stiffness in dialysis patients has prognostic significance. The TensioClinic device uses oscillometrically obtained wave forms to calculate pulse wave velocity (PWV) and augmentation index (AI). Our objective was assess the validity of measurements of TensioClinic (PWV_T, AI_T) compared to that of the validated PulsePen tonometer (PWV_P, AI_P).

We measured PWV and AIx in duplicate, before and after hemodialysis, in 94 hemodialysis patients. Reliability of a given device was assessed by calculating the standard deviation of the difference (SDD) between the first and second measurement. Validity of TensioClinic was evaluated by comparing its results to that obtained by the PulsePen device, using correlation analysis and Bland-Altman plots.

Predialysis SDD for PWV_P and PWV_T were –0.03±0.94 m/s and 0.51±1.35 m/s, postdialysis PWV_P and PWV_T SDD-s were 0.09±1.419 m/s and 0.07±1.81 m/s, respectively. Pre- and postdialysis SDD for AI_P and AI_T were 0.87±5.49% and 1.81±8.74%, and 0.79±4.01% and 3.54±22.69%. Mean predialysis PWV_Pwas 10.95±2.89 m/s and PWV_T 9.97±2.36 m/s. Postdialysis PWV_P was 11.59±2.92 m/s and PWV_T 10.37±3.24 m/s. Significant correlation was found between predialysis PWV_P and PWV_T (r = 0.28, p < 0.05). After dialysis the correlation was not significant (r = 0.16). Mean predialysis AI_P was 23.32±12.27% and AI_T 2.17±26.4%. Postdialysis AI_P and AI_T were 22.01±12.54% and –4.36±37.81%, respectively. Significant correlation was found between pre- and postdialysis AI_P and AI_T, r = 0.40 and 0.26, respectively.

PWV and AI measurements with PulsePen are more reproducible compared to TensioClinic. Poor correlation between the results obtained by the two devices may limit the use of TensioClinic in hemodialysis patients.