A restrictive or liberal approach: which is the best for patients with Acute Myocardial Infarction and Anemia?
Written by Todd Tessendorf, MD, FACC
The European Society of Cardiology’s Congress 2020 recently concluded. During this year’s digital seminar, the REALITY trial shed light on the management of anemia in the setting of acute coronary syndrome.
REALITY: Randomized Trial of Transfusion Strategies in Patients with Myocardial Infarction and Anemia
The goal of this trial was to assess the safety and efficacy of a restrictive versus liberal red blood cell (RBC) transfusion strategy among patients with acute myocardial infarction (AMI) and anemia.
Patients with acute myocardial infarction and hemoglobin (Hgb) ≤8 to ≤10 g/dl during admission were randomized in a 1:1 fashion to either a:
- Liberal (for Hgb ≤10 g/dl, goal Hgb >11 g/dl) (n = 342) or
- Restrictive (for Hgb ≤8 g/dl, target Hgb 8-10 g/dl) (n = 324) RBC transfusion strategy
The strategies should be maintained until discharge from hospital or for 30 days, whichever comes first.
- Total number of enrollees: 666
- Duration of follow-up: 30 days
- Mean patient age: 77 years
- Percentage female: 43%
- MI (ST-segment elevation MI [STEMI] or NSTEMI)
- Last ischemic symptoms <48 hours before admission
- Troponin elevation
- Anemia: Hb ≤10g/dl but >7 g/dl, at any time of index hospitalization for MI
- Cardiogenic shock
- Post-percutaneous coronary intervention (PCI) or post-coronary artery bypass grafting (CABG) MI
- Transfusion in the previous 30 days
- Any known hematologic disease
- Massive bleeding or compromising vital prognosis
The primary outcome, all-cause death, reinfarction, stroke and emergency revascularization prompted by ischemia for restrictive vs. liberal transfusion strategy, was 11.0% vs. 14.0% (hazard ratio 0.77, 95% confidence interval 0.50-1.18, p < 0.05 for noninferiority, p = 0.22 for superiority).
- All-cause mortality: 5.6% vs. 7.7% (p > 0.05)
- Recurrent MI: 2.1% vs. 3.1%
- Emergency revascularization: 1.5% vs. 1.9%
The results of this trial indicate that a restrictive PRBC transfusion strategy (transfusion for Hgb ≤8 g/dl, goal 8-10 g/dl) is non-inferior to a more liberal strategy (transfusion for Hgb ≤10 g/dl, goal Hgb >11 g/dl). In addition, infections and acute lung injury were higher with a more liberal strategy. Total blood utilization and costs were both lower with the restrictive strategy; this strategy was considered cost-dominant.
This is an important trial, and argues against the 10/30 rule that was once commonly practiced post-ACS (acute coronary syndrome). One minor point is that transfusions are frequently administered for Hgb ≤7 in clinical practice in the United States; the threshold studied in this trial was slightly higher (8 g/dl), possibly due to lack of equipoise for Hgb levels ≤7 g/dl. Similar results in favor of a restrictive strategy have been noted for post-cardiac and non-cardiac surgery patients.
At Bryan Heart we typically don’t recommend transfusions for patients who are anemic with ACS, as this has been our standard practice with post CABG patients; the information obtained through the REALITY trial confirms these efforts for any of our ACS patients.
If Bryan Heart can assist you with a patient screening or assessment, please call 402-483-3333.