Association of blood transfusion with increased mortality in myocardial infarction: a meta-analysis and
Saurav Chatterjee1, Jørn Wetterslev, Abhishek Sharma
1Division of Cardiology, Department of Medicine, Brown University, and Providence Veterans Affairs Medical Center, Providence, RI 02904, USA. sauravchatterjeemd@gmail.com
Insights
Blood transfusions in patients with myocardial infarction increase mortality risk. A liberal transfusion strategy is linked to higher death rates and subsequent heart attacks, suggesting caution is needed.
Area of Science:
- Cardiology
- Transfusion Medicine
Background:
- The role of blood transfusion in patients experiencing myocardial infarction (MI) remains controversial, with potential risks identified.
- Anemia is common in MI patients, often leading to transfusion decisions.
Purpose of the Study:
- To systematically review and analyze the impact of blood transfusion strategies on mortality in patients with myocardial infarction.
- To compare outcomes of liberal versus restricted blood transfusion approaches in this patient population.
Main Methods:
- A comprehensive literature search was conducted across multiple databases (MEDLINE, EMBASE, etc.) for studies published from 1966 to 2012.
- Ten English-language studies comparing blood transfusion versus no transfusion or liberal versus restricted strategies were selected and analyzed.
- Data on mortality outcomes and transfusion strategies were extracted, and study quality was assessed using the MOOSE checklist.
Main Results:
- Blood transfusion in MI patients was associated with significantly increased all-cause mortality (18.2% vs. 10.2%), a risk ratio of 2.91, and a number needed to harm of 8.
- This increased mortality risk persisted regardless of baseline or nadir hemoglobin levels.
- A higher risk of subsequent myocardial infarction was also observed with blood transfusion (risk ratio, 2.04).
Conclusions:
- Blood transfusion, particularly a liberal strategy, is linked to higher all-cause mortality rates in myocardial infarction patients.
- Routine or liberal blood transfusion practices in MI should be discouraged pending further investigation.
- Large, low-bias clinical trials are needed to definitively assess the risks and benefits of transfusion in MI.
Background:
The benefit of blood transfusion in patients with myocardial infarction is controversial, and a possibility of harm exists.
Methods:
A systematic search of studies published between January 1, 1966, and March 31, 2012, was conducted using MEDLINE, EMBASE, CINAHL, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials databases. English-language studies comparing blood transfusion with no blood transfusion or a liberal vs restricted blood transfusion strategy were identified. Two study authors independently reviewed 729 originally identified titles and abstracts and selected 10 for analysis. Study title, follow-up period, blood transfusion strategy, and mortality outcomes were extracted manually from all selected studies, and the quality of each study was assessed using the strengthening Meta-analysis of Observational Studies in Epidemiology checklist.
Results:
Studies of blood transfusion strategy in anemia associated with myocardial infarction were abstracted, as well as all-cause mortality rates at the longest available follow-up periods for the individual studies. Pooled effect estimates were calculated with random-effects models. Analyses of blood transfusion in myocardial infarction revealed increased all-cause mortality associated with a strategy of blood transfusion vs no blood transfusion during myocardial infarction (18.2% vs 10.2%) (risk ratio, 2.91; 95% CI, 2.46-3.44; P < .001), with a weighted absolute risk increase of 12% and a number needed to harm of 8 (95% CI, 6-17). Multivariate meta-regression revealed that blood transfusion was associated with a higher risk for mortality independent of baseline hemoglobin level, nadir hemoglobin level, and change in hemoglobin level during the hospital stay. Blood transfusion was also significantly associated with a higher risk for subsequent myocardial infarction (risk ratio, 2.04; 95% CI, 1.06-3.93; P = .03).
Conclusions:
Blood transfusion or a liberal blood transfusion strategy compared with no blood transfusion or a restricted blood transfusion strategy is associated with higher all-cause mortality rates. A practice of routine or liberal blood transfusion in myocardial infarction should not be encouraged but requires investigation in a large trial with low risk for bias.
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