Despite suggestions that higher serum magnesium (Mg) levels are associated with improved outcome, the association with mortality in European hemodialysis (HD) patients has only scarcely been investigated. Furthermore, data on the association between serum Mg and sudden death in this patient group is limited. Therefore, we evaluated Mg in a post-hoc analysis using pooled data from the CONvective TRAnsport STudy (CONTRAST, NCT00205556), a randomized controlled trial (RCT) evaluating the survival risk in dialysis patients on hemodiafiltration (HDF) compared to HD with a mean follow-up of 3.1 years. Serum Mg was measured at baseline and 6, 12, 24 and 36 months thereafter. Cox proportional hazards models, adjusted for confounders using inverse probability weighting, were used to estimate hazard ratios (HRs) of baseline serum Mg on all-cause mortality, cardiovascular mortality, non-cardiovascular mortality and sudden death. A generalized linear mixed model was used to investigate Mg levels over time. Out of 714 randomized patients, a representative subset of 365 (51%) were analyzed in the present study. For every increase in baseline serum Mg of 0.1 mmol/L, the HR for all-cause mortality was 0.85 (95% CI 0.77–94), the HR for cardiovascular mortality 0.73 (95% CI 0.62–0.85) and for sudden death 0.76 (95% CI 0.62–0.93). These findings did not alter after extensive correction for potential confounders, including treatment modality. Importantly, no interaction was found between serum phosphate and serum Mg. Baseline serum Mg was not related to non-cardiovascular mortality. Mg decreased slightly but statistically significant over time (Δ -0.011 mmol/L/year, 95% CI -0.017 to -0.009, p = 0.03). In short, serum Mg has a strong, independent association with all-cause mortality, cardiovascular mortality and sudden death in European HD patients. Serum Mg levels decrease slightly over time.

In post-dilution online haemodiafiltration (ol-HDF), a relationship has been demonstrated between the magnitude of the convection volume and survival. However, to achieve high convection volumes (>22 L per session) detailed notion of its determining factors is highly desirable. This manuscript summarizes practical problems and pitfalls that were encountered during the quest for high convection volumes. Specifically, it addresses issues such as type of vascular access, needles, blood flow rate, recirculation, filtration fraction, anticoagulation and dialysers. Finally, five of the main HDF systems in Europe are briefly described as far as HDF prescription and optimization of the convection volume is concerned.

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Background. Available evidence suggests a reduced mortality risk for patients treated with high-volume postdilution hemodiafiltration (HDF) when compared with hemodialysis (HD) patients. As the magnitude of the convection volume depends on treatment-related factors rather than patient-related characteristics, we prospectively investigated whether a high convection volume (defined as ≥22 L/session) is feasible in the majority of patients (>75%). Methods. A multicenter study was performed in adult prevalent dialysis patients. Nonparticipating eligible patients formed the control group. Using a stepwise protocol, treatment time (up to 4 hours), blood flow rate (up to 400 mL/min) and filtration fraction (up to 33%) were optimized as much as possible. The convection volume was determined at the end of this optimization phase and at 4 and 8 weeks thereafter. Results. Baseline characteristics were comparable in participants (n = 86) and controls (n = 58). At the end of the optimization and 8 weeks thereafter, 71/86 (83%) and 66/83 (80%) of the patients achieved high-volume HDF (mean 25.5 ± 3.6 and 26.0 ± 3.4 L/session, respectively). While treatment time remained unaltered, mean blood flow rate increased by 27% and filtration fraction increased by 23%. Patients with <22 L/session had a higher percentage of central venous catheters (CVCs), a shorter treatment time and lower blood flow rate when compared with patients with ≥22 L/session. Conclusions. High-volume HDF is feasible in a clear majority of dialysis patients. Since none of the patients agreed to increase treatment time, these findings indicate that high-volume HDF is feasible just by increasing blood flow rate and filtration fraction.

Background/Aims: Both all-cause and cardiovascular mortality risks are extremely high in patients with end-stage kidney disease (ESKD). Sudden death accounts for approximately one-quarter of all fatal events. Left ventricular hypertrophy (LVH) is a known risk factor for mortality and can be divided in 2 types: concentric and eccentric. This study evaluated possible differences in all-cause mortality, cardiovascular mortality and sudden death between prevalent ESKD patients with concentric and eccentric LVH. Methods: Participants of the CONvective TRAnsport STudy (CONTRAST) who underwent transthoracic echocardiography (TTE) at baseline were analyzed. In patients with LVH, a relative wall thickness of ≤0.42 was considered eccentric and >0.42 was considered concentric hypertrophy. Cox proportional hazards models, adjusted for potential confounders, were used to calculate hazard ratios (HRs) of patients with eccentric LVH versus patients with concentric LVH for all-cause mortality, cardiovascular mortality and sudden death. Results: TTE was performed in 328 CONTRAST participants. LVH was present in 233 participants (71%), of which 87 (37%) had concentric LVH and 146 (63%) eccentric LVH. The HR for all-cause mortality of eccentric versus concentric LVH was 1.14 (p = 0.52), 1.79 (p = 0.12) for cardiovascular mortality and 4.23 (p = 0.02) for sudden death in crude analyses. Propensity score-corrected HR for sudden death in patients with eccentric LVH versus those with concentric LVH was 5.22 (p = 0.03). Conclusions: (1) The hazard for all-cause mortality, cardiovascular mortality and sudden death is markedly increased in patients with LVH. (2) The sudden death risk is significantly higher in ESKD patients with eccentric LVH compared to subjects with concentric LVH.