P6.02 TOTAL ARTERIAL COMPLIANCE ESTIMATED BY A NOVEL METHOD AND ALL-CAUSE MORTALITY IN THE ELDERLY: THE PROTEGER STUDY

Abstract

Aortic stiffness assessed by carotid-to-femoral pulse wave velocity (PWV) often fails to predict cardiovascular (CV) risk and mortality in the very elderly. This may be due to the non-linear association between PWV and compliance, or to blood pressure decrease in the frailest subjects. Moreover, total arterial compliance (CT) is the most relevant arterial property regarding cardiac function and ventriculo-arterial coupling. A new method for CT estimation, based on PWV, was recently proposed. We aimed to investigate the value of this method to predict all-cause mortality at the elderly. Methods: PWV was estimated (Complior) in 279 elderly subjects (85.5±7.0 years) who were followed-up for a mean period of 1 year. CT was estimated by the formula CT=k×PWV−2; coefficient k is body-size dependent based on previous in silico simulations. In this study, k was adjusted for body mass index (BMI) with a 10% change in BMI corresponding to almost 11% change in k. For a reference BMI=26.2 kg/m2, k=37. Results: Survivors (n=185) and non-survivors (n=94) had similar PWV (14.2±3.6 versus 14.9±3.8 m/s, respectively; p=0.139). In contrast, non-survivors had significantly lower CT than survivors (0.221±0.1 versus 0.198±0.128 ml/mmHg; p=0.018). Cox-regression analysis showed that CT was a significant predictor of mortality (p=0.022, odds ratio=0.326), while PWV was not (p=0.202). Interestingly, age was an independent determinant of CT (p=0.016), but not of PWV. Conclusions: It was demonstrated that CT, estimated by a novel method, can predict all-cause mortality in the elderly. CT could be a more sensitive arterial biomarker than PWV regarding CV risk assessment. FigureReceiver-opertor-curve analysis of carotid-to-femoral pulse wave velocity (PWV) and total arterial compliance (inversed values) for the prediction of