#2032 Heart Rate-Adjusted Augmentation Index Reduces after Switching Low-Flux Dialyzers to Medium Cut-off Dialyzers in Maintenance Hemodialysis Patients

Abstract Background and Aims Arterial stiffness affects almost all maintenance hemodialysis (MHD) patients and is one of the most important predictors of cardiovascular morbidity and mortality. Medium cut-off (MCO) membrane technology provides higher clearance of large-middle uraemic toxin and cytokines compared to conventional dialyzers. In this case-control study, we investigated the change in the arterial stiffness parameters after the transition to MCO dialyzers in MHD patients receiving treatment with low-flux dialyzers. Method We conducted a prospective, single-center cross-over study including 19 MHD patients receiving treatment with low-flux dialyzers. Baseline and repeated parameters were measured from the brachial artery on a mid-week HD session at 0th, 120th, and 240th minutes, and the average of the three measurements were analyzed. The repeated parameters were measured two weeks after the switching to MCO dialyzers which were decided by the clinician according to clinical indication. Results The median age was 71 (51, 79) years, and 57.9% of the patients were female. The frequency of diabetes was 36.8%, and hypertension was 73.7%. 21.1% patients were smokers. 31.6% of the patients had a history of cardiovascular disease. Two weeks after switching to MCO dialyzers, the Kt/Vs, urea reduction ratios, laboratory parameters, systolic, diastolic, and mean arterial pressures remained similar to baseline. The mean pulse wave velocity was 10.3 m/s (8.4, 11.0) with low-flux dialyzers and 10.2 m/s (7.0, 11.5) with MCO dialyzers (p = 0.38). The mean heart rate adjusted augmentation index [AIx(75)] was 20.0% (15.0, 30.3) with low-flux dialyzers and 13.0% (11.0, 22.0) with MCO dialyzers (p = 0.04). Conclusion Our study showed that the rapid effect of MCO membranes is the reduction in peripheral wave reflections defined by AIx(75). Additional long-term diseases are required to determine whether MCO dialyzers might improve the cardiovascular prognosis of MHD patients.