Maintenance intravenous iron in hemodialysis patients to minimize erythropoietin doses: a double-blinded, randomized controlled trial (the MAINTAIN IRON trial)

In patients on chronic hemodialysis, there is no standard protocol for maintenance iron supplementation. This study aimed to compare two fixed-dose intravenous (IV) iron protocols to reduce erythropoiesis-stimulating agents (ESA). We conducted a double-blinded, randomized controlled study on hemodialysis patients having ferritin levels between 200 and 700 ng/dl and transferrin saturation values between 20 and 40%. Patients were assigned to receive either 100 or 200 mg of IV iron each month. ESA was adjusted every month to keep Hb between 10 and 12 g/dl. ESA dose at 12 months was the primary outcome. The secondary outcomes were all-cause mortality, cardiovascular events, absolute iron deficiency anemia (IDA), blood transfusion, adverse events, and iron withholding rate. Of the 79 eligible patients, 40 received 100 mg of IV iron, while 39 received 200 mg. At month 12, the mean monthly ESA dose in the 100-mg IV iron group was 35,706 ± 21,637 IU, compared to 26,382 ± 14,983 IU in the 200-mg group (P = 0.03). IDA was found in twelve patients (30%) in the 100-mg group and four patients (10.5%) in the 200-mg group (P = 0.05). In each group, three patients died (P = 0.9). Hospitalization, venous access thrombosis, and infection rates were similar in both groups. The withholding rate of IV iron was higher in 200-mg group (25% vs. 64.1%), but the protocol compliance was found more in 100-mg group (50% vs. 28.2%) (P = 0.001). In conclusion, monthly 200-mg IV iron infusions significantly reduce ESA doses but have a higher withholding rate. (Funded by the Kidney Foundation of Thailand and the Research Group in Nephrology and Renal Replacement Therapy from the Faculty of Medicine, Thammasat University). Thai Clinical Trials Registry number, TCTR20190707001.