Restrictive vs Liberal Transfusion Strategy After Myocardial Infarction: A Post Hoc Analysis of the MINT Randomized Clinical Trial.

IMPORTANCE

The decision to transfuse a patient with myocardial infarction (MI) and anemia at a higher vs lower hemoglobin threshold must consider the potential benefit of reduced risk of 30-day death or MI and the potential risk of heart failure.

OBJECTIVES

To estimate bayesian posterior risk differences and posterior probabilities that a liberal vs restrictive transfusion strategy is associated with reduced risk of 30-day death or MI and whether the probabilities exceed predefined thresholds.

DESIGN, SETTING, AND

PARTICIPANTS

The Myocardial Ischemia and Transfusion (MINT) trial recruited adults from April 26, 2017, to April 14, 2023, who were hospitalized with MI and anemia at 144 sites in 6 countries. Statistical analysis was performed from July 31, 2024, to February 18, 2026.

INTERVENTION: The MINT trial randomized participants to a restrictive (transfuse if hemoglobin is <7 to 8 g/dL) or liberal (maintain hemoglobin at >10 g/dL) transfusion strategy.

MAIN OUTCOMES AND MEASURES: Bayesian posterior risk differences were estimated for 30-day death or MI and for heart failure using 3 prior beliefs regarding the treatment strategies: noninformative, liberal strategy superiority, or restrictive strategy superiority.

RESULTS

The mean (SD) age of the 3504 participants was 72.1 (11.6) years and 1911 (54.5%) were men. Compared with the restrictive strategy, the risk of 30-day death or MI with the liberal strategy was 1.4% (95% credible interval, -0.8% to 3.5%) to 2.4% (95% credible interval, 0.3%-4.6%) lower, depending on prior beliefs. The probability that the liberal strategy was associated with a lower risk of 30-day death or MI ranged from 89.1% to 98.8%, and the probability that a liberal strategy was associated with at least 1 less death or MI per 100 treated was between 62.7% and 90.4%. Conversely, the risk of heart failure with the liberal strategy was 0.2% (95% credible interval, -1.6% to 1.2%) to 0.6% (95% credible interval, -2.0% to 0.8%) higher compared with the restrictive strategy, depending on prior beliefs. The probability that the liberal strategy was associated with a higher risk of heart failure ranged from 60.6% to 80.0%, and the probability that a liberal strategy was associated with at least 1 more heart failure event per 100 treated was between 13.3% and 29.3%.

CONCLUSIONS AND RELEVANCE: This post hoc analysis of a randomized clinical trial of patients with MI and anemia suggests that a liberal transfusion strategy was associated with a lower risk of 30-day death or MI, outweighing the increased risk of heart failure. Consistent with guideline recommendations and according to patients' values and clinician risk assessment, a liberal transfusion strategy may be reasonable.

TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02981407.