Restrictive Versus Liberal Transfusion in Symptomatic Coronary Artery Disease and Myocardial Infarction: A Meta-Analysis of Randomized Controlled Trials.

Background: In patients with coronary artery disease (CAD) and/or myocardial infarction (MI), anemia is associated with an increased risk of adverse cardiovascular (CV) outcomes. Transfusion goals in such patients remain unclear.

Study Question: A meta-analysis of the available randomized controlled trials (RCTs) was conducted comparing restrictive and liberal transfusion strategies in patients with symptomatic CAD/MI.

Data Sources: Multiple online databases including Cochrane, Pubmed, Embase, and MEDLINE were searched for RCTs.

Study Design: End points of interest were major adverse CV events (MACEs), MI, all-cause death, CV death, revascularization, heart failure (HF), and infection. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using a random-effects model.

Results: A total of 5 RCTs with 4518 patients-2258 in the restrictive transfusion group and 2260 in the liberal transfusion group-were included. The mean age was 72 years, and 59% of patients were men. At 30 days, MACE and MI were similar in the 2 transfusion groups. However, at the longest available follow-up, the restrictive strategy was associated with increased risks of MACE (OR 1.18, 95% CI, 1.02-1.37; P = 0.03) and MI (1.27, 95% CI, 1.02-1.58; P = 0.04), along with the higher trend of all-cause death (1.21, 95% CI, 1.00-1.46; P = 0.05) as compared with liberal transfusion. The 2 groups had comparable rates of CV death, revascularization, HF, and infection.

Conclusions: Liberal transfusion strategy may be associated with improved CV outcomes among patients with symptomatic CAD/MI as compared with a restrictive transfusion strategy.