Restrictive Versus Liberal Transfusion in Patients With Type 1 or Type 2 Myocardial Infarction: A Prespecified Analysis of the MINT Trial

Circulation. 2024 Dec 3;150(23):1826-1836. doi: 10.1161/CIRCULATIONAHA.124.071208. Epub 2024 Aug 29.

Abstract

Background: The MINT trial (Myocardial Ischemia and Transfusion) raised concern for harm from a restrictive versus liberal transfusion strategy in patients with acute myocardial infarction (MI) and anemia. Type 1 and type 2 MI are distinct pathophysiologic entities that may respond differently to blood transfusion. This analysis sought to determine whether the effects of transfusion varied among patients with a type 1 or a type 2 MI and anemia. The authors hypothesized that the liberal transfusion strategy would be of greater benefit in type 2 than in type 1 MI.

Methods: The authors compared rates of death or MI at 30 days in patients with type 1 (n=1460) and type 2 (n=1955) MI and anemia who were randomly allocated to a restrictive (threshold, 7-8 g/dL) or a liberal (threshold, 10 g/dL) transfusion strategy.

Results: The primary outcome of death or MI was observed in 16% of type 1 MI and 15.4% of type 2 MI patients. The rate of death or MI was higher in patients with type 1 MI randomized to a restrictive (18.2%) versus liberal (13.8%) transfusion strategy (relative risk [RR], 1.32 [95% CI, 1.04-1.67]) with no difference observed between the restrictive (15.8%) and liberal (15.1%) transfusion strategies in patients with type 2 MI (RR, 1.05 [95% CI, 0.85-1.29]). The test for a differential effect of transfusion strategy by MI type was not statistically significant (Pinteraction = 0.16).

Conclusions: The concern for harm with a restrictive transfusion strategy in patients with acute MI and anemia raised in the MINT primary outcome manuscript may be more apparent in patients with type 1 than type 2 MI.

Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02981407.

Keywords: acute coronary syndrome; blood transfusion; clinical trials as topic; myocardial infarction.

Publication types

  • Randomized Controlled Trial
  • Comparative Study
  • Multicenter Study

MeSH terms

  • Aged
  • Anemia* / diagnosis
  • Anemia* / etiology
  • Anemia* / mortality
  • Anemia* / therapy
  • Blood Transfusion* / methods
  • Female
  • Humans
  • Male
  • Middle Aged
  • Myocardial Infarction* / mortality
  • Myocardial Infarction* / therapy
  • Treatment Outcome

Associated data

  • ClinicalTrials.gov/NCT02981407