Abstract
BACKGROUND: Blood transfusion may precipitate adverse outcomes, including heart failure (HF), among patients with acute myocardial infarction (MI). This study characterizes the effects of a restrictive or liberal transfusion strategy on outcomes in patients with MI and anemia with and without baseline HF. METHODS: In the MINT trial (Myocardial Ischemia and Transfusion), 3504 patients with MI and anemia (hemoglobin <10 g/dL) were randomized to a restrictive (hemoglobin <8 g/dL) or liberal (hemoglobin <10 g/dL) transfusion strategy. We compared the effects of transfusion strategy on outcomes among patients with and without baseline HF. The primary outcome was death or HF at 30 days. RESULTS: Compared with patients without baseline HF (n=1633), those with baseline HF (n=1871) had higher rates of death or HF (18.0% versus 10.0%) at 30 days. Restrictive transfusion resulted in numerically higher rates of death or HF (rate ratio, 1.20 [95% CI, 0.99-1.45] versus 0.94 [95% CI, 0.70-1.26]; P(interaction)=0.18) in patients with than in those without baseline HF. Among secondary outcomes, death or recurrent MI and death were more frequent among those with baseline HF. Restrictive transfusion resulted in numerically higher rates of death or MI and death in patients with than in those without baseline HF. Rates of HF were similar between restrictive and liberal transfusion in patients with baseline HF but lower with restrictive transfusion (rate ratio, 0.51 [95% CI, 0.29-0.92]; P(interaction)=0.02) in patients without baseline HF. CONCLUSIONS: A liberal transfusion strategy is safe for patients with MI and anemia, including those with baseline HF. Restrictive transfusion tended to result in worse outcomes, particularly in patients with baseline HF. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02981407.