Liberal versus conservative transfusion strategy for patients with acute myocardial infarction and anemia: A systematic review and meta-analysis

Background: A hemoglobin (Hb) level goal of 7-8 g/dL is a standard care threshold, prompting blood transfusion. The debate over whether acute myocardial infarction (MI) patients benefit from a more liberal transfusion strategy prompted a meta-analysis of relevant trials.Methods: We performed a meta-analysis of randomized controlled trials (RCTs) comparing liberal and restrictive transfusion strategies in anemic MI patients. Primary outcomes were recurrent MI and death/MI, while secondary outcomes included stroke, revascularization, heart failure, and all-cause mortality. Due to the limited trials, we utilized the Paul-Mendele method with Hartung Knapp adjustment.Results: Involving 2155 patients with liberal transfusion and 2170 with conservative transfusion across four RCTs, liberal transfusion did not significantly reduce MI (relative risk [RR] 0.85; 95 % CI 0.72 -1.02, p = 0.07) or death/MI (RR 0.88; 95 % CI 0.45 -1.71, p = 0.57). No significant differences were observed in all-cause mortality (RR 0.82; 95 % CI 0.25 - 2.68, p = 0.63), stroke (RR 0.89; 95 % CI 0.48 -1.64, p = 0.50), revascularization (RR 0.93; 95 % CI 0.48 -1.80, p = 0.68), or heart failure (RR 1.14; 95 % CI 0.04 - 28.84, p = 0.88).Conclusion: Our meta-analysis supports current medical guidelines, reinforcing the practice of limiting transfusions in acute MI patients to those with an Hb level of 7 or 8 g/dL. Liberal transfusion strategies did not show improved clinical outcomes.