Preoperative IV iron cuts transfusion needs in cardiac surgery

Clinical takeaway: For patients with anemia awaiting elective cardiac surgery, preoperative IV iron can reduce the likelihood of red blood cell transfusion and may modestly improve recovery.

Anemia affects roughly one-third of patients undergoing cardiac surgery and substantially increases the likelihood of perioperative transfusion. A large randomized trial now provides evidence that treating anemia with IV iron before surgery can reduce transfusion requirements and increase the number of days patients are alive and at home during the first 90 days after surgery, a measure that accounts for time spent in the hospital or rehabilitation and for death.

The trial enrolled adults with anemia awaiting elective cardiac surgery. Among 921 patients assessed for the primary outcome, those assigned to a single 1,000-mg dose of IV iron spent a median 81.1 days alive and at home during the 90 days after surgery, compared with 80.0 days with placebo—an adjusted difference of one day. The difference was small overall, although exploratory analyses suggested a larger benefit among patients with poorer recovery profiles.

The clearer clinical effect was on transfusion. During hospitalization, 61.1% of patients receiving IV iron required a red blood cell transfusion versus 68.2% with placebo—meaning about 7 fewer patients needed a transfusion for every 100 treated with IV iron. Overall, IV iron saved approximately 44 units of red blood cells for every 100 patients treated.

Importantly, all patients had anemia, but only about 59% of those tested met the study criteria for iron deficiency. IV iron raised preoperative hemoglobin and increased the likelihood that anemia had resolved by the time of surgery. Benefits were similar regardless of documented iron deficiency, suggesting that IV iron may benefit some patients with preoperative anemia even when iron deficiency is not clearly demonstrated.

IV iron did not reduce major postoperative complications or length of hospital stay. Adverse events were generally similar between groups, although hypophosphatemia was more common with IV iron.

Together, the findings strengthen the case for identifying and treating anemia before elective cardiac surgery, with IV iron as a potential strategy to reduce transfusion needs.

“This study shows that intravenous iron repletion in patients with anaemia before cardiac surgery increased preoperative haemoglobin concentration, reduced the need for red cell transfusion, and resulted in an extra day at home in the first 90 days after surgery,” the authors concluded.

Source: Myles PS, et al. (2026 Aug 19) BMJ. Intravenous iron to treat anaemia before cardiac surgery (ITACS): international, double blind, placebo controlled randomised trial