Restrictive blood transfusion non-inferior and cost-effective strategy

According to results of the REALITY trial, the largest randomised trial in this setting, restrictive blood transfusion has no negative impact on clinical outcomes compared with a more liberal strategy in anaemic patients with an acute myocardial infarction (AMI) [1]. Incidence rates of infections and acute lung injury were lower with the restrictive strategy.

The optimal transfusion strategy in anaemic patients with AMI is unclear. Observational studies have reported that blood transfusion may be associated with a higher mortality rate in patients with AMI, and only 2 small randomised trials have been conducted, with conflicting results.

The REALITY trial enrolled 666 patients (mean age 77 years; 43% female) with AMI and haemoglobin (Hgb) 8-10 g/dL during admission, who were randomised to either a liberal or restrictive red blood cell (RBC) transfusion strategy. In the restrictive strategy, transfusion was withheld unless Hgb was ≤8 g/dL, with a target Hgb 8-10 g/dL (n=324); and in the liberal strategy, a transfusion was given as soon as Hgb was ≤10 g/dL, with a target Hgb >11 g/dL (n=342).

The primary outcome, a composite of all-cause mortality, reinfarction, stroke, and emergency percutaneous coronary intervention (PCI) prompted by ischaemia, occurred in 11.0% of patients who received the restrictive strategy, and in 14.0% of patients who received the liberal strategy (HR 0.77; P<0.05 for non-inferiority; P=0.22 for superiority; see Figure).

Figure: Restrictive strategy non-inferior to liberal strategy in the REALITY trial [1]



Mace, all-cause death, reinfarction, stroke, and emergency revascularisation prompted by ischaemia.

The individual components of the primary outcome occurred in the following percentages of patients in the restrictive versus the liberal transfusion strategy groups:

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    • All-cause mortality: 5.6% vs 7.7% (P>0.05);
    • Recurrent myocardial infarction: 2.1% vs 3.1%; and
    • Emergency revascularisation: 1.5% vs 1.9%.

 

With respect to safety, patients allocated to the restrictive strategy were significantly less likely to develop an infection (0.0% vs 1.5%; P=0.03) or acute lung injury compared with the liberal strategy (0.3% vs 2.2%; P=0.03). Total 30-day hospital costs were €11,051 versus €12,572 (P=0.1).

The REALITY trial supports the use of a restrictive strategy for blood transfusion in AMI patients with anaemia. The restrictive strategy saves blood, is safe, and is at least as effective in preventing 30-day cardiac events compared with a liberal strategy, while saving money. Similar results in favour of a restrictive strategy have been noted for post-cardiac and non-cardiac surgery patients.

 

1. 
   
   1. Steg PG. REALITY - A Trial of Transfusion Strategies for Myocardial Infarction and Anemia. Hot Line 4 session, ESC Congress 2020, 31 Aug.

 



Posted on 5 November, 202028 March, 2024