December 23, 2024NEJM Evidence21 citationsOpen Access
Restrictive versus Liberal Transfusion in Myocardial Infarction — A Patient-Level Meta-Analysis
Key Result
A restrictive transfusion strategy in MI and anemia showed no definitive difference in 30-day mortality or MI compared to a liberal strategy (15.4% vs 13.8%; RR 1.13, 95% CI 0.97-1.30).
Study Design
Type
Meta-Analysis (n=4,311)
Multicenter
Yes
Structured PICO
Does a restrictive red cell transfusion strategy reduce 30-day mortality or MI in patients with acute myocardial infarction and anemia compared to a liberal strategy?
P
Population
4,311 patients from four trials with acute myocardial infarction (MI) and anemia
I
Intervention
Restrictive red cell transfusion strategy (transfusion threshold of 7-8 g/dl)
C
Comparator
Liberal red cell transfusion strategy (transfusion threshold of 10 g/dl)
O
Outcome
Composite of 30-day mortality or MIcomposite
In patients with MI and anemia, a restrictive transfusion strategy did not significantly differ from a liberal strategy for the composite of 30-day death or MI, but was associated with increased 30-day cardiac death and 6-month all-cause mortality.
Main Result
Effect estimate: RR 1.13 (95% CI 0.97-1.30)
Absolute Event Rate: 15.4% vs 13.8%
Abstract
BACKGROUND: Clinical guidelines have concluded that there are insufficient data to provide recommendations for the hemoglobin threshold for the use of red cell transfusion in patients with acute myocardial infarction (MI) and anemia. After the recent publication of the Myocardial Infarction and Transfusion (MINT) trial, we performed an individual patient-level data meta-analysis to evaluate the effect of restrictive versus liberal blood transfusion strategies. METHODS: We conducted searches in major databases. Eligible trials randomly assigned patients with MI and anemia to either a restrictive (i.e., transfusion threshold of 7-8 g/dl) or liberal (i.e., transfusion threshold of 10 g/dl) red cell transfusion strategy. We used individual patient data from each trial. The primary outcome was a composite of 30-day mortality or MI. RESULTS: We included 4311 patients from four trials. The primary outcome occurred in 334 patients (15.4%) in the restrictive strategy and 296 patients (13.8%) in the liberal strategy (relative risk RR 1.13, 95% confidence interval CI, 0.97 to 1.30). Death at 30 days occurred in 9.3% of patients in the restrictive strategy and in 8.1% of patients in the liberal strategy (RR 1.15, 95% CI, 0.95 to 1.39). Cardiac death at 30 days occurred in 5.5% of patients in the restrictive strategy and in 3.7% of patients in the liberal strategy (RR 1.47, 95% CI, 1.11 to 1.94). Heart failure (RR 0.89, 95% CI, 0.70 to 1.13) was similar in the transfusion strategies. All-cause mortality at 6 months occurred in 20.5% of patients in the restrictive strategy compared with 19.1% of patients in the liberal strategy (hazard ratio 1.08, 95% CI, 1.05 to 1.11). CONCLUSIONS: Pooling individual patient data from four trials did not find a definitive difference in our primary composite outcome of MI or death at 30 days. At 6 months, a restrictive transfusion strategy was associated with increased all-cause mortality. (Partially funded by a grant from the U.S. National Heart, Lung, and Blood Institute R01HL171977.).