Day-to-day repeatability of the Pulse Time Index of Norm

Igor N Posokhov,1 Aleksandra O Konradi,2 Eugeny V Shlyakhto,2 Oleg V Mamontov,2 Artemy V Orlov,3 Anatoly N Rogoza4 1Hemodynamic Laboratory Ltd, Nizhniy Novgorod, 2Almazov Federal Heart, Blood and Endocrinology Centre, Saint Petersburg, 3Department 65 Competitive System Analysis, National Research Nuclear University, Moscow, 4Cardiology Research Center, Moscow, Russia Abstract: The pulse wave velocity (PWV) threshold for hypertensive target organ damage is presently set at 10 meters per second. New 24-hour monitors (eg, BPLab® and Vasotens®) provide several PWV measurements over a period of 24–72 hours. A new parameter, ie, the Pulse Time Index of Norm (PTIN), can be calculated from these data. The PTIN is defined as the percentage of a 24-hour period during which the PWV does not exceed 10 meters per second. The aim of the present study was to test the new PTIN for clinical feasibility using day-to-day repeatability analysis. Oscillometrically generated waveform files (n=85), which were previously used for research studies, were reanalyzed using the new 2013 version software of the Vasotens technology program, which enables calculation of PTIN. The intraclass correlation coefficient was 0.98 and Cronbach's alpha was 0.97, indicating that the PTIN has excellent day-to-day repeatability and internal consistency. The present results show adequate repeatability, and PTIN assessment using the Vasotens technology appears to be feasible. Keywords: pulse wave velocity, ambulatory, 24-hour, monitoring, Pulse Time Index of Norm, arterial stiffnes