New AABB Guideline on Red Cell Transfusion in Acute MI

Written by Clay Smith

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A transfusion trigger of less than 10g/dL appears to lower 30-day mortality in patients with acute myocardial infarction (AMI).

Apparently, the more the merrier… for red cells in MI
This is updated AABB guidance on the transfusion threshold when patients are having AMI. This matters, as up to 40% of elderly patients with AMI are anemic. Two major trials, the MINT RCT and REALITY RCT (both covered on JournalFeed!), have recently been published, but results conflicted, necessitating this update of the guidelines.

Here is the upshot:

• “For hospitalized patients with AMI, the international panel suggests RBC transfusion when the Hb is less than 10 g/dL (conditional recommendation, low-certainty evidence).”
• Consider the individual patient’s “history, signs, symptoms, hemodynamic status” and preferences when considering transfusion.
• Mitigate harms of transfusion by “optimizing fluid status peri-transfusion, slowing transfusion rate, prescribing diuretics, achieving the target Hb more gradually, and transfusing during renal replacement therapy sessions for renal failure.”

They meta-analyzed 4 trials, N=4311. For 30-day mortality, RR 0.87 (95%CI 0.72 to 1.06). Although this was not statistically significant, this group of experts determined a priori that 1% was the minimal important difference (MID) in mortality they thought patients would consider significant. The absolute 30-day mortality risk difference was 9.3% restrictive vs. 8.1% liberal, a 1.2% absolute risk reduction (NNT = 84), which exceeded the MID.

How will this change my practice?
After the REALITY RCT, I thought a liberal transfusion strategy in MI was out. Then MINT made me wonder. Overall, it looks like there is a slight signal for better outcomes with a transfusion trigger of <10 g/dL. I will cautiously transfuse anemic patients with MI based on this guideline.

Source
Red Cell Transfusion in Acute Myocardial Infarction: AABB International Clinical Practice Guidelines. Ann Intern Med. 2025 Aug 19. doi: 10.7326/ANNALS-25-00706. Epub ahead of print. PMID: 40825204.