Jeffrey Carson, MD
Image Credit: Jeffrey Carson, MD
New data from a trial of more than 3,500 patients suggest that a more liberal transfusion strategy may improve outcomes in patients with acute myocardial infarction and anemia.
Results presented at the 2023 American Heart Association Scientific Sessions showed that the MINT trial failed to meet its primary endpoint of statistical significance for the composite of all-cause death and recurrent heart disease within 30 days, but the results showed a non-significant trend among patients in the liberally transfused group. Benefit, major events occurred in 16.9% of the restrictive transfusion group and 14.5% of the liberal transfusion group.1
“Low red blood cell counts or anemia are common among patients hospitalized for heart disease,” said study investigator Jeff Lee L. Carson, MD, says. .2 “We believe our results suggest that a more liberal approach to blood transfusion may be beneficial to these patients without significant risks.”
The Myocardial Ischemia and Transfusion (MINT) trial was funded by the National Heart, Lung, and Blood Institute and was designed to expand the current evidence base to inform future guidance on transfusion strategies for patients with myocardial infarction. MINT was an open-label interventional trial conducted at 144 sites in the United States, Canada, France, Brazil, New Zealand, and Australia, randomizing patients with myocardial infarction with hemoglobin levels less than 10 g/dL to a restrictive or liberal transfusion strategy. , which were defined as transfusions with a hemoglobin cutoff of 7 or 8 g/dL and a hemoglobin cutoff of less than 10 g/dL, respectively.1
To be included in the trial, patients with STEMI or NSTEMI had to be 18 years or older and have a hemoglobin level less than 10 g/dL within 24 hours of randomization. The researchers noted that patients with type 1, 2, 4b or 4c myocardial infarction were eligible.1
A total of 3504 people underwent randomization and were included in the study’s main analysis. The cohort had a mean prerandomization hemoglobin level of 8.6 g/dL, a mean age of 72.1 years, and 45.5% were female. The researchers noted that type 2 and type 1 myocardial infarction accounted for the majority of this cohort, accounting for 55.8% and 41.7% of the entire cohort, respectively.1
Patients enrolled in the trial were followed for 30 days, and the primary composite endpoint was myocardial infarction or death at 30 days. The trial also included multiple prespecified secondary outcomes, such as individual components of the primary outcome and a composite of death, myocardial infarction, ischemia-driven unplanned coronary revascularization, or readmission for ischemic heart disease within 30 days. ending.1
The results of the analysis showed that the average number of red blood cell units transfused in the restrictive strategy group and the liberal strategy group were 0.7 (standard deviation (SD), 1.6) and 2.5 (SD, 2.3), respectively. Further analysis showed that 1 to 3 days after randomization, mean hemoglobin levels were 1.3 to 1.6 g/dL lower in the restrictive strategy group than in the liberal strategy group.1
The primary outcome analysis showed that at 30 days, 16.9% of people in the restrictive strategy group had myocardial infarction or death from any cause and 14.5% of people in the liberal strategy group had myocardial infarction or death from any cause, which was consistent with a crude risk ratio (RR) of 1.16. ) correlation (95% confidence interval (95% confidence interval) CI), 1.00 to 1.35). After adjustment for site and incomplete follow-up in 57 patients, the risk of the primary outcome event was increased by 15% in the restrictive transfusion group.1
Further analysis of the results showed that death occurred in 9.9% of the restrictive strategy group and 8.3% of the liberal strategy group (RR, 1.19; 95% CI, 0.96 to 1.47), while myocardial infarction occurred in 8.5% and 7.2% of patients, respectively. respectively (RR, 1.19; 95% CI, 0.94 to 1.49).1
“The findings require nuanced interpretation. While the trial’s main results did not show a statistically significant difference between the two transfusion strategies, the results suggest that liberal transfusions may confer benefits without Undue risk,” Carson said.2 “The MINT results suggest that a liberal transfusion strategy may be the most prudent approach for patients with heart disease and anemia.”
refer to:
- Carson JL, Brooks MM, Herbert PC, et al. Restrictive or liberal transfusion strategies in myocardial infarction and anemia. New England Journal of Medicine. Published online on November 11, 2023. doi:10.1056/NEJMoa2307983
- Red blood cell transfusions may improve outcomes in heart disease patients with anemia. American Heart Association. November 11, 2023. Accessed 11 November 2023. https://newsroom.heart.org/news/red-blood-cell-transfusions-may-improve-outcomes-in-heart-attack-patient-with-anemia.