Viscoelastic blood tests use in adult cardiac surgery: meta-analysis, meta-regression and trial sequential analysis

Abstract Objective(s) Postoperative hemorrhage in cardiac surgery is a significant cause of morbidity and mortality. Standard laboratory tests fail as predictors for bleeding during surgical setting. The use of viscoelastic (VE) hemostatic assays thromboelastography (TEG®) and rotational thromboelastometry (ROTEM®) could be an advantage in patients undergoing cardiac surgery. The objective of this meta-analysis was to analyze the effects (benefits and harms) of VE-guided transfusion practice in cardiac surgery patients. Design A meta-analysis of randomized trials. Setting We searched PubMed, EMBASE, Scopus and the Cochrane Collaboration database. We included only randomized controlled trials. We performed a systematic review and meta-analysis in accordance with the standards set forth by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, using a random-effect model. Partecipants Adult cardiac surgery patients. Interventions VE-hemostatic assays transfusion algorithm compared with transfusion algorithms based on clinicians’ discretion. Measurements and Main Results Seven comparative randomized controlled trials were considered, including a total of 1035 patients (522 patients in whom a TEG® or ROTEM®-based transfusion algorithm were used). In patients treated according to VE guided algorithms, red blood cells (odd ratio (OR) 0.61, 95% confidence interval (CI) 0.37-0.99, p 0.04, I 2 66%) and fresh frozen plasma transfusions (risk difference 0.22, 95% CI 0.11-0.33, p 2 79%) use was reduced; platelets transfusion was not reduced (OR 0.61, 95% CI 0.32-1.15, p 0.12, I 2 74%). Conclusions This study seems to demonstrate that the use of VE assays in cardiac surgical patients is effective in reducing allogenic blood products exposure, postoperative bleeding at 12 and 24 hours after surgery and the need for re-operation unrelated to surgical bleeding.