Survival Outcomes with High-Volume Hemodiafiltration Versus High-Flux Hemodialysis in Incident Patients: A...

High-volume online hemodiafiltration has been associated with better outcomes compared with high-flux hemodialysis, but evidence from Latin America has been limited.

We conducted a retrospective multicenter cohort study including patients who initiated chronic dialysis between 01-Jan-2020 and 30-Sep-2022 across 84 clinics currently operated by NEFRA Medical Care. Patients receiving peritoneal dialysis, pediatric patients, and those with fewer than 90 days on dialysis were excluded to reduce early modality-instability bias and ensure sufficient time for treatment modality classification. The primary outcome was all-cause survival comparing hemodiafiltration with high-flux hemodialysis in the propensity score-matched cohort. Secondary and exploratory outcomes evaluated survival by delivered substitution volume and vascular access type. Propensity score matching used age, sex, diabetes, vascular access, and baseline laboratory values. Survival was estimated using Kaplan-Meier methods and compared using the log-rank test.

After matching, 1154 patients were included, with 577 per group. For the primary outcome, mean survival was longer with hemodiafiltration than with high-flux hemodialysis (1446 versus 1231 days; log-rank P < 0.001). For the secondary outcome, survival differed by substitution volume (log-rank P < 0.001), with the longest survival among patients receiving high-volume hemodiafiltration. In exploratory analyses, survival differed by vascular access type (log-rank P < 0.001), with the most favorable survival among patients receiving hemodiafiltration with an arteriovenous fistula.

In this Argentine incident cohort, hemodiafiltration was associated with longer survival than high-flux hemodialysis. Higher substitution volume and arteriovenous fistula use were associated with the most favorable outcomes. Findings should be interpreted considering the observational design and potential residual confounding.