New AABB international clinical practice guidelines on red cell transfusion in acute myocardial infarction

New AABB international clinical practice guidelines on red cell transfusion in acute myocardial infarction

26 September 2025

Current guidelines advocate for a restrictive red blood cell (RBC) transfusion strategy over a liberal one in most hospitalised patient groups. However, uncertainty regarding optimal RBC transfusion strategies for patients with acute myocardial infarction (AMI) remains as highlighted in the 2023 Guidelines from the Association for the Advancement of Blood & Biotherapies (AABB). With the recent publication of two large randomised controlled trials (RCTs), the AABB commissioned this AMI specific guideline to reassess the current evidence-base for this patient group.   

The multidisciplinary international panel utilised GRADE methodology. Meta-analysis of eligible trials was conducted, with a total of 4 trials, comprising of 4,311 participants. The MINT (Myocardial Ischemia and Transfusion) trial enrolled 3,504 participants, and the REALITY (Restrictive and Liberal Transfusion Strategies in Patients with AMI) trial included 666 participants, one pilot trial comprised of 96 participants with AMI and a single institution trial included 45 participants with AMI.  

All 4 trials (n = 4311) evaluated 30-day mortality, with a pooled risk ratio of 0.87 (95% CI, 0.72 to 1.06). The analysis revealed 1.2% fewer deaths with a liberal RBC transfusion strategy (when Hb < 100 g/L), surpassing the panel-defined minimal important difference of 1%. This suggested a restrictive strategy (Hb 70 to 80 g/L) may result in increased mortality in patients with AMI.  

For hospitalised patients with AMI, the international panel suggests a liberal red cell transfusion strategy when the Hb is < 100 g/L (conditional recommendation, low-certainty evidence). The panel highlighted that the recommendation does not apply to AMI patients with haemodynamic instability (due to the challenging nature of transfusion decision making in this context) or to patients without AMI (the trials only included those with AMI). They also noted that a liberal threshold of 100 g/L might not apply to all patients with AMI, and that current evidence does not allow for identification of those patients with AMI who would benefit the most from a liberal threshold. 

An accompanying Good Practice Statement highlights the importance of incorporating the individual clinical context (including history, signs, symptoms, haemodynamic status) and the patient’s preferences when weighing RBC transfusion decisions. A valuable discussion of clinical considerations is provided within the guideline. In view of the higher risk for serious adverse events associated with the liberal transfusion strategy, risk mitigation approaches for transfusion associated circulatory overload are addressed.  PBM strategies including early recognition and treatment of the underlying causes of anaemia are also reinforced.  

Research gaps are highlighted, including factors that may influence the benefits and harms of transfusion according to the mechanism of MI and patient specific characteristics. As noted in the accompanying editorial: 

‘These guidelines mark only the beginning, not the culmination, of a worthwhile scientific inquiry. Meanwhile, clinicians should apply these guidelines with sound clinical judgment to tailor transfusion therapy in shared decision making that incorporates individual patients’ values and preferences.’ 

 

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