4.7 PARAMETERS OF THE RESERVOIR-WAVE APPROACH AND MORTALITY IN DIALYSIS POPULATION

Abstract

Background: A new model has been proposed to explain hemodynamic consequences of arterial stiffness, which integrates both wave propagation and aortic reservoir function. The aim of this study was to assess the association between parameters of reservoir-wave analysis and all-cause mortality in a population with accelerated vascular ageing. Methods: Among 311 patients with chronic kidney disease on dialysis, central arterial pressures were derived from applanation tonometry (Sphygmocor) of radial artery. Reservoir wave analysis was applied on radial pressure waveforms (without generalized transfer function) to obtain reservoir pressure (Peak RP), its integral (RP integral), excess pressure parameters (Peak XS, XS integral), and systolic (SC) and diastolic time constant (DC). Results: During a median follow-up of 33 months, 204 (66%) deaths occurred. In Kaplan–Meier survival curves, only increasing tertiles of DC was associated with a significant decrease in survival time (p < 0.001). Amongst all parameters, only DC and XS integral were predictors of all-cause mortality in univariate Cox analysis as shown by hazard ratios for changes in 1-standardized deviation (HR 1-SD, Table 1). However, DC and XS integral were no longer significant when age was introduced in the model (p-value > 0.179). Continuous variables HR 1-SD 95% CI p-value Peak RP(mmHg) 1.121 0.987–1.273 0.079 RP integral(mmHg·sec) 1.050 0.920–1.197 0.470 Peak XS(mmHg) 1.112 0.966–1.281 0.138 XS integral(mmHg·sec) 1.217 1.062–1.395 0.005 SC(×10−2) 1.099 0.970–1.244 0.138 DC(×10−2) 1.186 1.60–1.328 0.003 Conclusions: Amongst all parameters of the reservoir-wave analysis, DC was the most important parameter associated with survival time and mortality. Despite its hypothetically more integrated approach to arterial tree function, none of the derived parameters showed a robust and independent association with mortality in this population. The study shows that despite its simplicity, arterial stiffness gradient remains the best predictor of mortality in this population.