Previous randomized, controlled trials have provided inconclusive results on whether the dialysis techniques, hemodiafiltration or hemodialysis, possessed superior survival benefits for patients with kidney failure.¹ The CONVINCE trial took this issue a step further to compare high-dose hemodiafiltration with hemodialysis for their survival outcomes.¹ Results of this study suggested that the implementation of high-dose hemodiafiltration provided more beneficial survival outcomes for patients with end-stage kidney disease.¹  

Hemodiafiltration and hemodialysis are the conventional therapies for treating kidney failure, with hemodialysis being more commonly utilized.¹ Nevertheless, a recent meta-analysis has illustrated the possibility that hemodiafiltration might positively impact the survival outcomes for patients with end-stage kidney disease, reducing the risk of overall and cardiovascular (CV) mortality by 14% and 23%, respectively.² Results of this meta-analysis also suggested a potential correlation of patients who received high-dose hemodiafiltration having more favorable survival outcomes.² As such, CONVINCE study was conducted to elucidate the survival benefits between high-dose hemodiafiltration and high-flux hemodialysis.¹ 

The CONVINCE trial was an international, prospective, open-label, multicenter, pragmatic, randomized, controlled trial that enrolled 1,360 adult patients who were diagnosed with stage V kidney failure, had previously received hemodialysis treatment for at least 3 months, and was eligible for high-dose hemodiafiltration (i.e., ≥23 liters of convection volume in post-dilution mode per session).¹ The participants were randomized 1:1 to initiate either high-dose hemodiafiltration or continue the high-flux hemodialysis treatment.¹ The primary endpoint of this study was the overall mortality of the patient groups.¹ The key secondary endpoints consisted of cause-specific mortality, the composite outcome of fatal and non-fatal CV events, kidney transplantation, and recurrent hospitalization for any causes and for causes relating to infection.¹ 

With a median follow-up period of 30 months, the analysis results of the study highlighted the survival benefits of high-dose hemodiafiltration, as the study observed a 23% reduction in the overall mortality risk with the use of high-dose hemodiafiltration compared with high-flux hemodialysis (HR=0.77; 95% CI: 0.65-0.93; p=0.005).¹ Subsequently, the survival outcomes differed in accordance with the patient’s preexisting medical history.¹ Notably, more pronounced survival outcomes were observed among patients without CV diseases (HR=0.58; 95% CI: 0.42-0.79) and patients without diabetes mellitus (HR=0.65; 95% CI: 0.48-0.87) in both treatment groups.¹ Additionally, the study also concluded a marked decline in the mortality risk in senior patients aged ≥65 years, with a hazard ratio of 0.68 in the high-dose hemodiafiltration cohort (95% CI: 0.53-0.89).¹ 

As to the secondary endpoints, the risk of death from CV events (HR=0.81; 95% CI: 0.49-1.33), the composite outcome of fatal and non-fatal CV events (HR=1.07; 95% CI: 0.86-1.33), the rates of recurrent non-fatal hospitalization (HR=1.11; 95% CI: 0.98-1.25), the rate of infection-related hospitalization including Coronavirus disease 2019 (COVID-19) (HR=1.06; 95% CI: 0.86-1.30) and excluding COVID-19 (HR=0.97; 95% CI: 0.74-1.26) were similar, while no significant difference was present between the 2 cohorts.¹ Nevertheless, high-dose hemodiafiltration treatment was associated with a decreased risk of infection-related death by 31% (HR= 0.69; 95% CI: 0.49-0.96).¹ 

To conclude, high-dose hemodiafiltration has been shown to provide more desirable survival outcomes compared with the conventional high-flux hemodialysis among patients with kidney failure in the CONVINCE trial.¹ Thus, the results of this trial encourage further studies to investigate whether the survival benefits of high-dose hemodiafiltration are broadly applicable to other patient populations and subgroups.¹