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

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.

Red cell extracellular vesicles and coagulation activation pathways

“…The risk of VTE includes both deep venous thrombosis and pulmonary embolism and seems to increase with the amount of PRBCs transfused [64,66]. Restrictive transfusion strategy may reduce the risk of VTE [70 ▪ ], further supporting a potential role of PRBC transfusion in VTE. Despite the large number of studies, their observational design hampers a conclusion of causality between PRBC transfusion and VTE.…”

Etablierung eines Patient Blood Managements als Behandlungsstandard

“…Transfusionen von Erythrozytenkonzentraten (EK) sind mittlerweile zwar sehr sicher, aber ggf. mit einer erhöhten Morbidität assoziiert, sodass eine evidenzbasierte Gabe von EK-Transfusionen empfohlen wird [11,12,13]. Laut Bundeszentrale für gesundheitliche Aufklärung werden in Deutschland aktuell täglich ca.…”

Primum, non nocere: Whole blood, prehospital transfusion and anti‐D hemolytic disease of the fetus and newborn

“…36 In addition, most randomized trials of restrictive versus liberal transfusion strategies have shown no benefit or even harm in the liberal group. 37 Particularly pertinent to patients with active bleeding are the TRICS-III trial and a trial involving patients with upper gastrointestinal (GI) bleeding. 38,39 The former involved intraoperative cardiac surgery patients, and the restrictive strategy (7.5 g/dl) was non-inferior to a liberal strategy (<9.5 g/dl) for the composite outcome of death, myocardial infarction, stroke, and renal failure.…”