Abstract
Background and Aims
Pulse wave morphology changes under the high flow condition of reactive hyperaemia. We hypothesized, that those alterations may be able to indicate endothelial dysfunction.
Method
We recorded digitized pulse waves measured tonometrically with the SphygmoCor® device of 64 persons, 41 kidney transplant recipients and 23 healthy individuals, under normal conditions (NC) and under reactive hyperaemia (RH). Using matlab®, we calculated novel parameters, which had a temporal relationship with 3 charactereristic points (PO) of the normalized pulse wave, namely the maximum of the antegrade wave (1), the diacrotic notch (2) and the first diastolic inflection point (3). The following parameters were calculated: Mean slope between PO 1 and 2 (λ2), area under the curve (AUC) in the systole (Asys), AUC between PO 1 and 3 (A13), AUC between PO 1 and 2 (A12) and AUC between PO 2 and 3 (A23). Parameters were analyzed as their difference under reactive hyperaemia and under normal conditions. Also the maximum of the instantaneous difference of normalized pulse waves under NC und RH (Dmax) was analyzed. Endothelial function was evaluated by duplex sonography using ROC-analysis of peak systolic and end-diastolic flow difference under NC and RH.
Results
ROC-assessment of endothelial dysfunction as indicated by systolic peak flows demonstrated AUCs of 0.733 for λ2 (p=0.002), 0.751 for Dmax (p< 0.001), 0.698 for Asys (p=0.006), 0.648 for A13 (p=0.077), 0.678 for A12 (p=0.027) and 0.732 for A23 (p=0.001). For the diastole the values were 0.753 for λ2 (p=0.003), 0.733 for Dmax (p=0.002) 0.670 for Asys (p=0.038), 0.566 for A13 (p=0.495), 0.664 for A12 (p=0.091) and 0.722 for A23 (p=0.015) respectively.
Conclusion
Pulse wave analysis under the condition of reactive hyperaemia probably is useful to assess endothelial function in kidney transplant recipients.
Ambulatory Blood Pressure in Kidney Transplant Recipients: More Questions than Answers
