Ambulatory arterial stiffness in chronic kidney disease: a methodological review

Cardiovascular mortality is the leading cause of death in chronic kidney disease (CKD) and end-stage renal disease (ESRD). This can be explained in part by an increased and progressive calcification of the medial layer of the large arteries leading to arterial stiffening. The prognostic value of measurements of arterial stiffness, especially pulse wave velocity (PWV), in the general population and in CKD and ESRD patients is high, and is above that of traditional risk factors with respect to cardiovascular outcome. In recent years, as an alternative to office measurements, methods for monitoring ambulatory arterial stiffness have been developed. The ambulatory arterial stiffness index (AASI) allows derivation of a parameter from ambulatory blood pressure measurements; however, doubts have emerged about the usefulness of this parameter. Recently, new oscillometric methodologies using simple brachial cuffs, such as Mobil-O-Graph, Vasotens or Arteriograph 24, have been introduced. They measure parameters of 24-h arterial stiffness including PWV, augmentation index and central blood pressure. This enables study of the 24-h variability of these parameters, which will hopefully lead to better cardiovascular risk stratification and improved cardiovascular outcomes of patients. Our review summarizes the present data and future directions of AASI and the methods for monitoring oscillometric 24-h stiffness in different patient populations and especially in CKD.