Impact of frequent hemodialysis on anemia management: results from the Frequent Hemodialysis Network (FHN) Trials

Abstract

The extent to which anemia management is facilitated by more frequent hemodialysis (HD) is controversial. We hypothesized as a preselected outcome that patients receiving HD six times (6×) compared with three times (3×) per week would require lower doses of erythropoietin-stimulating agents (ESA) and/or achieve higher blood hemoglobin (Hb) concentrations. Subjects enrolled in the Frequent Hemodialysis Network (FHN) daily and nocturnal trials were studied. As the primary outcome for anemia, the dose of ESAs was recorded at 4-month intervals and the monthly dose of intravenous iron (IV Fe) was reported. Serum iron, transferrin saturation and ferritin were measured at baseline and then at 4-month intervals, whereas Hb concentration was measured monthly. There was no significant treatment effect in the 6× versus 3× treatment groups on logESA dose or the ratio of log of ESA dose to Hb concentration in either trial. In the daily trial, Hb concentrations increased significantly in the 6× versus 3× group, at Month 12 compared with baseline (0.3 g/dL; 95% CI: 0.05-0.58, P<0.021), but both groups had Hb concentrations in the usual target range. In the daily trial, the weekly logESA dose and the logESA dose to Hb concentration ratio tended to decline more in the 6× versus 3× group. This trend was not observed in the nocturnal trial. IV Fe doses were significantly lower in the 6× compared with the 3× group by Month 12 in the nocturnal trial, but not different in the daily trial. In the FHN Daily and Nocturnal Trials, more frequent HD did not have a significant or clinically important effect on anemia management.