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. 2021 Feb;25(11):1–58. doi: 10.3310/hta25110

Preoperative intravenous iron for anaemia in elective major open abdominal surgery: the PREVENTT RCT.

Toby Richards, Ravishankar Rao Baikady, Ben Clevenger, Anna Butcher, Sandy Abeysiri, Marisa Chau, Rebecca Swinson, Tim Collier, Matthew Dodd, Laura Van Dyck, Iain Macdougall, Gavin Murphy, John Browne, Andrew Bradbury, Andrew Klein
PMCID: PMC7957457  PMID: 33632377

Abstract

BACKGROUND

Anaemia affects 30-50% of patients before they undergo major surgery. Preoperative anaemia is associated with increased need for blood transfusion, postoperative complications and worse patient outcomes after surgery. International guidelines support the use of intravenous iron to correct anaemia in patients before surgery. However, the use of preoperative intravenous iron for patient benefit has not been assessed in the setting of a formal clinical trial.

OBJECTIVES

To assess if intravenous iron given to patients with anaemia before major abdominal surgery is beneficial by reducing transfusion rates, postoperative complications, hospital stay and re-admission to hospital, and improving quality of life outcomes.

DESIGN

A multicentre, double-blinded, randomised, controlled, Phase III clinical trial, with 1 : 1 randomisation comparing placebo (normal saline) with intravenous iron (intravenous ferric carboxymaltose 1000 mg). Randomisation and treatment allocation were by a secure web-based service.

SETTING

The study was conducted across 46 hospitals in England, Scotland and Wales between September 2013 and September 2018.

PARTICIPANTS

Patients aged > 18 years, undergoing elective major open abdominal surgery, with anaemia [Hb level of > 90 g/l and < 120 g/l (female patients) and < 130 g/l (male patients)] who could undergo randomisation and treatment 10-42 days before their operation.

INTERVENTION

Double-blinded study comparing placebo of normal saline with 1000 mg of ferric carboxymaltose administered 10-42 days prior to surgery.

MAIN OUTCOME MEASURES

Co-primary end points were risk of blood transfusion or death at 30 days postoperatively, and rate of blood transfusions at 30 days post operation.

RESULTS

A total of 487 patients were randomised (243 given placebo and 244 given intravenous iron), of whom 474 completed the trial and provided data for the analysis of the co-primary end points. The use of intravenous iron increased preoperative Hb levels (mean difference 4.7 g/l, 95% confidence interval 2.7 to 6.8 g/l; p < 0.0001), but had no effect compared with placebo on risk of blood transfusion or death (risk ratio 1.03, 95% confidence interval 0.78 to 1.37; p = 0.84; absolute risk difference +0.8%, 95% confidence interval -7.3% to 9.0%), or rates of blood transfusion (rate ratio 0.98, 95% confidence interval 0.68 to 1.43; p = 0.93; absolute rate difference 0.00, 95% confidence interval -0.14 to 0.15). There was no difference in postoperative complications or hospital stay. The intravenous iron group had higher Hb levels at the 8-week follow-up (difference in mean 10.7 g/l, 95% confidence interval 7.8 to 13.7 g/l; p < 0.0001). There were a total of 71 re-admissions to hospital for postoperative complications in the placebo group, compared with 38 re-admissions in the intravenous iron group (rate ratio 0.54, 95% confidence interval 0.34 to 0.85; p = 0.009). There were no differences between the groups in terms of mortality (two per group at 30 days post operation) or in any of the prespecified safety end points or serious adverse events.

CONCLUSIONS

In patients with anaemia prior to elective major abdominal surgery, there was no benefit from giving intravenous iron before the operation.

FUTURE WORK

The impact of iron repletion on recovery from postoperative anaemia, and the association with reduced re-admission to hospital for complications, should be investigated.

LIMITATIONS

In the preoperative intravenous iron to treat anaemia in major surgery (PREVENTT) trial, all patients included had anaemia and only 20% had their anaemia corrected before surgery. The definition and causality of iron deficiency in this setting is not clear.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN67322816 and ClinicalTrials.gov NCT01692418.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25 No. 11. See the NIHR Journals Library website for further project information.

Plain language summary

In patients undergoing major surgery, anaemia (low blood count) is a common problem. Anaemia is often a consequence of the disease necessitating surgery and can make people feel tired and unwell. Anaemia increases the need for a blood transfusion at the time of surgery, and patients with anaemia have more complications from surgery, prolonged hospital stay and delayed recovery. Iron deficiency is the most common cause of anaemia. An iron infusion has been shown to be effective to rapidly treat anaemia, but it is not known if this is effective in treating anaemia in the presurgical setting, and whether or not this may benefit patients. The main aim of this study was to assess if intravenous iron can treat anaemia in patients before major surgery and if this will reduce the need for blood transfusion, make patients feel better and, consequently, help them do better during and after surgery. A total of 487 patients with anaemia were recruited from 46 UK hospitals before major abdominal surgery. Patients were randomly allocated to receive an infusion of iron or placebo 10 days to 6 weeks before their surgery. Patients were followed up at 8 weeks and 6 months after their surgery. Intravenous iron increased the blood count in patients before surgery. There was no difference in blood transfusion rates or patient deaths between those who received intravenous iron and those who received placebo. Similarly, there was no difference in the patients’ postoperative complications or length of hospital stay. Patients who received iron had a higher blood count at 8 weeks and 6 months post operation and there were fewer re-admissions to hospital for complications. In conclusion, for patients undergoing major surgery, giving intravenous iron to treat anaemia before the operation did not reduce the need for blood transfusion. Further work is needed to evaluate whether or not there is any benefit after discharge from hospital.

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