Meta-analysis: Hemodiafiltration Reduces Mortality in Kidney Failure Patients Compared to Hemodialysis
7 Nov, 2024 | 12:19h | UTCBackground: Kidney failure patients undergoing hemodialysis face high mortality rates, with approximately 50% dying within five years of initiating treatment. Hemodiafiltration, a convection-based therapy that removes a broader spectrum of uraemic toxins, has been proposed to improve survival outcomes. Previous studies have shown mixed results regarding its efficacy, and uncertainties remain about its effects on specific patient subgroups, dose-response relationships with convection volume, and cause-specific mortality.
Objective: To compare the effects of online hemodiafiltration versus standard hemodialysis on all-cause and cause-specific mortality in patients with kidney failure.
Methods: An individual patient data meta-analysis of five randomized controlled trials was conducted, encompassing 4,153 patients (2,083 on hemodiafiltration and 2,070 on hemodialysis). Databases including MEDLINE, Embase, and the Cochrane Central Register were searched up to July 17, 2024. The primary outcome was all-cause mortality. Subgroup analyses based on patient characteristics and dose–response analyses using convection volume were performed.
Results: Over a median follow-up of 30 months, all-cause mortality occurred in 477 patients (23.3%) receiving hemodiafiltration and 559 patients (27.0%) receiving hemodialysis. Hemodiafiltration significantly reduced all-cause mortality (hazard ratio [HR] 0.84, 95% CI 0.74–0.95) compared to hemodialysis. Cardiovascular mortality was also lower in the hemodiafiltration group (HR 0.78, 95% CI 0.64–0.96), particularly deaths due to cardiac causes (HR 0.67, 95% CI 0.50–0.89). No differential effects were observed across predefined patient subgroups. A dose-dependent relationship was found between higher convection volumes and reduced mortality risk.
Conclusions: Hemodiafiltration significantly reduces all-cause and cardiovascular mortality in patients with kidney failure compared to standard hemodialysis. The mortality benefit is dose-dependent, with higher convection volumes associated with greater risk reductions.
Implications for Practice: These findings support the adoption of online hemodiafiltration as a superior alternative to conventional hemodialysis. Clinicians should consider implementing high-dose hemodiafiltration to improve survival outcomes in patients with kidney failure.
Study Strengths and Limitations: Strengths include the large sample size and use of individual patient data, allowing for comprehensive subgroup and dose–response analyses. Limitations involve heterogeneity among the included studies and potential biases due to open-label designs. The lack of blinding may have influenced outcome reporting.
Future Research: Further studies are needed to evaluate the long-term benefits of hemodiafiltration on patient-reported outcomes, cost-effectiveness, and environmental impacts. Investigations into the optimal convection volumes and the mechanisms underlying the observed mortality reductions are also warranted.