Compared with placebo, preoperative intravenous (IV) iron was not superior in reducing the need for blood transfusions in patients with anemia who underwent elective major abdominal surgery, according to study results published in The Lancet.1

For patients undergoing surgery with an expected blood loss of 500 mL or more, guidelines from the National Institute for Health and Care Excellence recommend that patients should be screened for anemia at least 2 weeks prior to surgery.2 The guidelines also recommend that patients with anemia should be treated with IV iron. Despite these recommendations, the evidence supporting the use of IV iron to reduce blood transfusion among this patient group is of low quality. In addition, the diagnosis of iron deficiency in patients with preoperative anemia is also not clear. To address these gaps in knowledge, a team of investigators conducted the PREVENTT trial, a double-blind, parallel-group, placebo-controlled, randomized trial (ISRCTN67322816), to assess the clinical efficacy of IV iron therapy in patients with anemia 10 to 42 days prior to elective major abdominal surgery. Primary endpoints were the risk of composite outcome of blood transfusion or mortality, and the number of blood transfusions from baseline to 30 days after surgery.

A total of 487 patients were randomly assigned (1:1) to either placebo (243 patients) or IV iron (244 patients), and 97% of participants had complete data for primary endpoints. Patients in the placebo group has a median age of 65 years (58% women) and patients in the IV iron group had a median age of 66 years (51% women).

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From men and women, anemia was defined as hemoglobin concentrations less than 130 g/L and 120 g/L, respectively. Patients in the IV iron cohort were administered a 1000 mg dose of ferric carboxymaltose in 100 mL and saline, while patients in the placebo group were administered a single dose of 100 mL normal saline; both infusions were administered over 15 minutes.

Between randomization and 30 days after surgery, 29% of all patients received at least 1 blood transfusion or died; 28% of patients in the placebo group and in 29% of patients in the IV iron group (risk ratio, 1.03; 95% CI, 0.78-1.37; P =.84).

A total of 216 transfusion episodes (111 in the placebo group and 105 in the IV group) were recorded from randomization to 30 days after surgery, and no significant differences were observed between patient groups (rate ratio, 0.98; P =.93).

Six months after surgery there was still not a significant difference in coprimary endpoints among both patient groups (risk ratio for blood transfusion or death, 0.99; rate ratio for transfusion episodes, 0.92).

“The primary results of our trial show no evidence of clinical benefit in giving [IV] iron preoperatively to patients undergoing major abdominal surgery and provide the highest quality of evidence to date, with sufficient statistical power to make strong inferences about effectiveness,” the authors wrote.

“The evidence base now suggests that current guidance on preoperative iron therapy by, for example, [National Health Service] England and [National Institute for Health and Care Excellence], should be revised and now state that preoperative iron therapy is not recommended in major elective surgery patients with [anemia],” the investigators noted.   

Disclosures: Some authors have declared affiliations with or received funding from the pharmaceutical industry. Please refer to the original study for a full list of disclosures.


  1. Richards T, Baikady RR, Clevenger B, et al. Preoperative intravenous iron to treat anaemia before major abdominal surgery (PREVENTT): a randomised, double-blind, controlled trial. Lancet. Published online September 4, 2020. doi:10.1016/S0140-6736(20)31539-7
  2. Blood Transfusion NICE Guideline. National Institute for Health and Care Excellece. Published November 18, 2015. Access October 22, 2020.