Restrictive vs Liberal Blood Transfusion Strategy in Acute Myocardial Infarction and Anemia
REALITY trial design and results
Design
Randomised non-inferiority clinical trial
Treatment
Restrictive transfusion strategy
Control
Liberal transfusion strategy
Population
666 patients with acute myocardial infarction and anaemia, median age 77, 42.2% women
Follow-up
30 days
Primary endpoint
Major adverse cardiovascular events at 30 days
Result
Major adverse cardiovascular events at 30 days occurred in 36 of 342 (11.0%, 95% CI 7.5 to 14.6) with the restrictive strategy and 45 of 324 (14.0%, 10.0 to 17.9) with the liberal strategy — difference -3.0 percentage points (95% CI -8.4 to 2.4), relative risk 0.79, meeting the prespecified non-inferiority criterion. Transfusion was given to 122 restrictive-group patients (35.7%) and 323 liberal-group patients (99.7%). All-cause death was 5.6% versus 7.7%.
Among patients with acute myocardial infarction and anemia, a restrictive compared with a liberal transfusion strategy resulted in a noninferior rate of MACE after 30 days. However, the CI included what may be a clinically important harm.
The trial authors, in the published abstract
How it has aged
Points the other way from MINT, which was five times larger and could not exclude harm from restriction — and note that REALITY's own authors could not either, saying so in their conclusion. Non-inferiority in 666 patients is a weaker claim than it sounds; the threshold in this setting remains genuinely unsettled.
Publications
Effect of a Restrictive vs Liberal Blood Transfusion Strategy on Major Cardiovascular Events Among Patients With Acute Myocardial Infarction and Anemia: The REALITY Randomized Clinical Trial
Ducrocq G, Gonzalez-Juanatey JR, Puymirat E, et al. Effect of a Restrictive vs Liberal Blood Transfusion Strategy on Major Cardiovascular Events Among Patients With Acute Myocardial Infarction and Anemia: The REALITY Randomized Clinical Trial. JAMA 2021 Feb 9;325(6):552-560.
Restrictive strategy met the non-inferiority margin for major adverse cardiovascular events