Impact of restrictive red blood cell transfusion strategy on thrombosis-related events: A meta-analysis and systematic review

School of Management, University of Science and Technology of China, Hefei, Anhui, China. Lee Kong Chian School of Business, Singapore Management University, Singapore. School of Management, Technical University of Munich, Heilbronn, Germany. Munich Data Science Institute, Technical University of Munich, Munich, Germany. Department of Cardiac, Thoracic and Vascular Surgery, National University Hospital, Singapore.

Vox sanguinis. 2022
PICO Summary

Population

Adult patients in any clinical setting (30 studies, n= 17,334).

Intervention

Restrictive red blood cell transfusion.

Comparison

Liberal red blood cell transfusion.

Outcome

The pooled risk ratio (RR) for thromboembolic events was 0.65 (very low-quality evidence), favouring the restrictive strategy. There were no significant differences in cerebrovascular accidents (RR= 0.83, very low-quality evidence) or myocardial infarction (RR= 1.05, low-quality evidence). Subgroup analyses showed that a restrictive (relative to liberal) strategy reduced thromboembolic events in trials conducted in North America, and myocardial infarctions in the subgroup of trials where the restrictive transfusion threshold was 7 g/dl but not in the 8 g/dl subgroup (with a liberal transfusion threshold of 10 g/dl in both subgroups).
Abstract
BACKGROUND AND OBJECTIVES There is an ongoing controversy regarding the risks of restrictive and liberal red blood cell (RBC) transfusion strategies. This meta-analysis assessed whether transfusion at a lower threshold was superior to transfusion at a higher threshold, with regard to thrombosis-related events, that is, whether these outcomes can benefit from a restrictive transfusion strategy is debated. MATERIALS AND METHODS We searched PubMed, Cochrane Central Register of Controlled Trials and Scopus from inception up to 31 July 2021. We included randomized controlled trials (RCTs) in any clinical setting that evaluated the effects of restrictive versus liberal RBC transfusion in adults. We used random-effects models to calculate the risk ratios (RRs) and 95% confidence intervals (CIs) based on pooled data. RESULTS Thirty RCTs involving 17,334 participants were included. The pooled RR for thromboembolic events was 0.65 (95% CI 0.44-0.94; p = 0.020; I(2) = 0.0%, very low-quality evidence), favouring the restrictive strategy. There were no significant differences in cerebrovascular accidents (RR = 0.83; 95% CI 0.64-1.09; p = 0.180; I(2) = 0.0%, very low-quality evidence) or myocardial infarction (RR = 1.05; 95% CI 0.87-1.26; p = 0.620; I(2) = 0.0%, low-quality evidence). Subgroup analyses showed that a restrictive (relative to liberal) strategy reduced (1) thromboembolic events in RCTs conducted in North America and (2) myocardial infarctions in the subgroup of RCTs where the restrictive transfusion threshold was 7 g/dl but not in the 8 g/dl subgroup (with a liberal transfusion threshold of 10 g/dl in both subgroups). CONCLUSIONS A restrictive (relative to liberal) transfusion strategy may be effective in reducing venous thrombosis but not arterial thrombosis.
Study details
Study Design : Systematic Review
Language : eng
Credits : Bibliographic data from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine