A restrictive transfusion strategy is appropriate for most hospitalized patients.

A restrictive transfusion strategy (hemoglobin [Hb] cutoff, <7 g/dL) is accepted widely as the standard of care for most hospitalized patients with anemia, but controversy remains for some subgroups (NEJM JW Gen Med May 1 2021 and JAMA 2021; 325:552). In October 2023, the Association for the Advancement of Blood and Biotherapies conducted a systematic review to update their 2016 guideline (JAMA 2016; 316:2025) on red blood cell (RBC) transfusions. The updated guideline recommends the restrictive 7 g/dL cutoff for most hemodynamically stable patients, although clinicians “may choose” slightly higher thresholds for patients with preexisting cardiovascular disease and for patients undergoing orthopedic or cardiovascular surgery. However, for patients with acute myocardial infarction (MI), evidence was considered to be inadequate to make a specific recommendation (NEJM JW Gen Med Nov 15 2023 and JAMA 2023; 330:1892). Just a few weeks later (in November 2023), researchers published findings from the largest-ever
clinical trial to address transfusion in patients with acute MI and anemia. About 3500 patients were randomized to a restrictive threshold (Hb cutoff, <7 or <8 g/dL, per clinician judgment) or a liberal threshold (Hb cutoff, <10 g/dL). Key 30-day adverse outcomes occurred less often with the liberal than with the restrictive transfusion strategy — 8.3% versus 9.9% for death, 7.2% versus 8.5% for recurrent MI, and 14.5% versus 16.9% for the composite of death or recurrent MI. These outcomes were of borderline statistical significance; one possible explanation is that the trial might have been underpowered because more than half of patients had type 2 MIs (supply–demand mismatch), yet virtually all benefit occurred among patients with type 1 MIs (coronary occlusion), who accounted for only 42% of participants. The incidence of new or worsening heart failure, a well-described adverse event associated with RBC transfusion, was slightly (but not significantly) higher with the liberal strategy (NEJM JW Gen Med
Dec 15 2023 and N Engl J Med 2023 Nov 11; [e-pub]).

The above-noted guideline confirms that a restrictive transfusion strategy is appropriate for most hospitalized patients with anemia. However, the new large, randomized trial suggests that a more liberal approach should be considered for patients with acute MI — and particularly those with type 1 MI. — Andrew S. Parsons, MD, MPH

Dr. Parsons is Associate Professor of Medicine and Public Health at the University of Virginia School of Medicine, Charlottesville.

NON-2024-2048