P6.24: Clinical Feasibility of the New Pulse Time Index of Norm (Ptin) and its Correlation to Left Ventricular Mass Index

Background Recently the pulse wave velocity (PWV) threshold of hypertensive target organ damage (TOD) was set at 10 m/s. New 24 — h monitors (e.g., BPLab-Vasotens) provide not only 1 PWV but several PWV measurements over a 24 — h period. The new Pulse Time Index of Norm (PTIN) can be calculated from these data. The PTIN is defined as the percentage of a 24 — h period during which the PWV does not exceed 10 m/s. The idea is to adopt the new PWV measurements for the definition of TOD and sharpen its level of detection. The aim of the present study is to test the new PTIN for clinical feasibility and its correlation to left ventricular mass index (LVMI). Methods Oscillometrically generated waveform files (n=510, measurements ranging from a single point to 72 hours), which were previously used for clinical research, were re-analysed using the new 2013 software version of the Vasotens technology program, which enables PTIN calculation. Results The cut-off point at 10 m/s in the ROC curve showed a sensitivity of 93.3% and a specificity of 81.5% for single measurements of PWV compared to SphygmoCor. The reference interval of PTIN was equal to 83.2% (lower limit). Reliability statistics showed Cronbach’s alpha was 0.967 for day-today repeatability (i.e., excellent internal consistency of PTIN). Good correlation (r=−0.72) between PTIN and LVMI was shown, and it was significantly above the blood pressure load (r=0.41). Conclusion Calculating PTIN from Vasotens technology is clinically feasible and seems to enhance the discriminatory power of detecting TOD.