Restrictive versus Liberal Blood Transfusion Strategy in Patients With Acute Myocardial Infarction: A Meta-Analysis...

Area of Science:

• Cardiology
• Transfusion Medicine
• Clinical Trials

Background:

• Observational studies suggest liberal blood transfusion (LBT) may increase mortality in acute myocardial infarction (AMI).
• Randomized clinical trials (RCTs) comparing restrictive blood transfusion (RBT) to LBT in AMI patients with anemia are limited.
• A meta-analysis of RCTs in this specific population has not been previously conducted.

Purpose of the Study:

• To evaluate the clinical efficacy of RBT versus LBT in patients with AMI and anemia.
• To assess the impact on all-cause mortality, recurrent myocardial infarction (MI), revascularization, and heart failure exacerbation.

Main Methods:

• Systematic literature search of Ovid MEDLINE, EMBASE, Cochrane Central, Scopus, and Google Scholar up to June 19th, 2021.
• Inclusion of RCTs comparing RBT and LBT strategies.
• Primary endpoint: all-cause mortality; Secondary endpoints: recurrent MI, revascularization, heart failure exacerbation.

Main Results:

• Three RCTs involving 821 patients (421 RBT, 400 LBT) were included.
• RBT showed no significant reduction in all-cause mortality (RR=1.61; p=0.52).
• No significant differences were observed for recurrent MI (RR=0.98; p=0.94), revascularization (RR=1.18; p=0.83), or heart failure exacerbation (RR=0.86; p=0.82) with RBT compared to LBT.

Conclusions:

• Restrictive blood transfusion (RBT) is not associated with improved outcomes in patients with AMI and anemia compared to LBT.
• The study did not find RBT to be superior in reducing mortality, recurrent MI, revascularization, or heart failure exacerbation.
• Larger RCTs are warranted to definitively establish the optimal transfusion strategy in this patient cohort.