THE PROGNOSTIC ASSOCIATION OF AMBULATORY PULSE WAVE VELOCITY WITH ALL-CAUSE MORTALITY IN PATIENTS UNDERGOING PERITONEAL DIALYSIS: A PROSPECTIVE OBSERVATIONAL STUDY

Objective: Novel devices are now available to enable the recording of central hemodynamic parameters and arterial stiffness indices in ambulatory conditions. The prognostic significance of ambulatory pulse wave velocity (PWV), a marker of arterial stiffness, in end-stage kidney disease (ESKD) patients undergoing long-term peritoneal dialysis (PD) remains unknown. Design and method: In this prospective observational study, 140 stable ESKD from 3 PD centers of Northern Greece were included. At baseline, all patients underwent assessment of PWV over a 24-hour ambulatory blood pressure monitoring with the oscillometric device Mobil-O-Graph device (I.E.M. GmbH, Stolberg, Germany). Subsequently, these patients were prospectively followed for the evaluation of the risk of death from any cause. The value of 24-hour ambulatory PWV as a predictor of all-cause death risk was assessed using univariate- and multivariate-adjusted Cox regression hazard models. Results: The study included 140 PD patients (86 males) with a median age of 65 (18-89) years. Over a median follow-up period of 25 months [interquartile range (IQR): 13-47], 38 patients (27.1%) died. In Kaplan-Meier survival analysis 24-hour ambulatory PWV appeared to be of prognostic significance, with all-cause mortality being higher in patients with 24-hour ambulatory PWV greater or equal than 9.35 m/s (Log Rank p value = 0.013). In univariate Cox regression analysis, patients with higher 24-hour ambulatory PWV at baseline had a 1.87-fold higher risk of all-cause mortality during the follow-up period [hazard ratio (HR): 1.87; 95% confidence interval (CI): 1.13–3.09]. However, after adjustment for several confounding factors (age, mode of PD, diabetic status, history of pre-existing cardiovascular disease, blood pressure medication use, hemoglobin and serum albumin levels at baseline, residual kidney function), 24-hour ambulatory did not remain an independent predictor of survival (HR: 0.70; 95% CI: 0.30-1.61). Conclusions: The present study shows that among ESKD patients undergoing long-term PD, 24-hour ambulatory PWV, as assessed with the Mobil-O-Graph device, is not an independent predictor of all-cause death risk after adjustment for multiple risk factors. Whether this marker can enable the better stratification of cardiovascular risk in the PD population requires examination in future studies.