Reply: Potential association between aortic stiffness, diastolic/systolic pressure time index and the balance between cardiac oxygen supply and demand: A word of caution

We thank Drs Chemla and Nitenberg for their comments. We also appreciate their acknowledgement of the noninvasiveness of the study and the high number of included individuals.
In their first comment, they discuss the methods to transform the measured finger to aortic pressure. Indeed, we took great care to obtain the best possible reconstruction by individualization with the return-to-flow calibration. Recently, we again demonstrated the precision of the method. Further, the study population of Rongen et al., mentioned by Chemla et al. was evaluated in the original publication of the return-to-flow method and showed good results. It may be noted that radial applanation tonometry always needs additional calibration. The use of a generalized transfer function may be insufficient for diagnosing an individual, but in large study groups correct results may be expected, as we discussed in our publication.
The second point is that not taking the left ventricular diastolic pressure into account as originally proposed by Buckberg et al. may undermine our results. [...]