Hemodialysis Modality and Mortality Outcomes among Incident Dialysis Patients

KEY POINTS: High-volume hemodiafiltration was associated with a 20% lower all-cause mortality risk compared with hemodialysis in incident patients. High-volume hemodiafiltration was associated with a 29% lower cardiovascular mortality risk compared with hemodialysis in incident patients. Associations between high-volume hemodiafiltration and lower mortality were consistent across demographic and clinical subgroups. BACKGROUND: Evidence for a survival benefit of hemodiafiltration (HDF) over high-flux hemodialysis largely comes from studies based on prevalent ESKD patients with longer dialysis exposure. By contrast, the effect of HDF on mortality of incident patients-those newly starting dialysis-remains less well understood. METHODS: We analyzed data from 18,515 incident patients (dialysis vintage <3 months) treated between 2019 and 2022 at Fresenius Medical Care NephroCare Clinics. Patients were classified as HDF or hemodialysis on the basis of their predominant dialysis modality during the first year of follow-up (≥75% of sessions). To assess the effect of HDF in the early phase after treatment initiation, follow-up was limited to 2 years. Cox proportional hazards models with inverse probability of treatment weighting were applied to estimate all-cause and cardiovascular disease mortality risk. RESULTS: Baseline characteristics between HDF and hemodialysis groups were comparable after inverse probability of treatment weighting. Over a median follow-up of 15.7 months (interquartile range, 6.4-24.0 months), HDF was associated with a lower risk of all-cause mortality compared with hemodialysis (11.7 versus 15.6 per 100 person-years; hazard ratio, 0.80; 95% confidence interval, 0.75 to 0.86). Furthermore, HDF was associated with a lower risk of cardiovascular disease mortality compared with hemodialysis (4.1 versus 6.7 per 100 person-years; hazard ratio, 0.71; 95% confidence interval, 0.63 to 0.80). CONCLUSIONS: In the large real-world cohort of incident patients with ESKD who are in the early phase of dialysis treatment, online HDF was associated with a significant survival advantage compared with conventional hemodialysis. These findings reinforce the potential clinical benefits of HDF and support early adoption of HDF upon dialysis initiation.