2025 Mar 17, 08:08
The Myocardial Ischemia and Transfusion (MINT) trial, a new open-label, multi-center randomized controlled trial, has examined the impact of restrictive and liberal transfusion strategies in patients with myocardial infarction (MI) and anemia. The trial enrolled adult patients with MI, both STEMI and NSTEMI, and anemia with hemoglobin levels less than 10 g/dL. In the restrictive-strategy group, transfusion was recommended when the hemoglobin level was less than 7 g/dL or when anginal symptoms were not controlled with medications. In the liberal-strategy group, one unit of packed red cells was administered after randomization and red cells were transfused to maintain the hemoglobin level at or above 10 g/dL. The primary outcome of the trial was a composite of MI and death within 30 days after randomization
The trial enrolled 3,506 patients, with the majority having type 2 MIs. The mean hemoglobin at enrollment was 86 g/L. The trial showed a clear difference between the groups in terms of treatment given, with the mean hemoglobin rising by about 10 g/L in the liberal group and staying the same in the restrictive group. However, significantly more patients in the liberal group had to discontinue the protocol due to adverse events such as fluid overload. The primary composite outcome was not statistically different between the groups
Mortality was slightly higher in the restrictive group compared to the liberal group, while the incidence of MI was also slightly higher in the restrictive group. The trial has raised important points regarding statistical significance, bias, and the heterogeneity introduced by including both type 1 and type 2 MIs. Additionally, the trial's unblinded nature and subjective components of the protocol, such as treating when angina is not controlled by medications, may have introduced bias. The trial does not provide definitive answers and further research is needed. Considering the available data that suggests benefit from restrictive transfusions, it may be prudent to adopt a relatively restrictive transfusion strategy as a baseline. However, clinicians should continue to use their judgment and individualize patient management
This trial does not support blanket treatment recommendations, as there are known harms associated with transfusions. Overall, the MINT trial enhances our understanding of transfusion strategies in patients with MI and anemia but does not provide conclusive results. Continued clinical judgment and further research are necessary to guide transfusion strategies in this patient population.