Routine use of viscoelastic blood tests for diagnosis and treatment of coagulopathic bleeding in cardiac surgery: updated systematic review and meta-analysis

Viscoelastic point-of-care tests are commonly used to provide prompt diagnosis of coagulopathy and allow targeted treatments in bleeding patients. We updated existing meta-analyses that have evaluated the clinical effectiveness of viscoelastic point-of-care tests vs the current standard of care for the management of cardiac surgery patients at risk of coagulopathic bleeding. Randomized controlled trials comparing viscoelastic point-of-care diagnostic testing with standard care in cardiac surgery patients were sought. All-cause mortality, blood loss, reoperation, blood transfusion, major morbidity, and intensive care unit and hospital length of stay were analysed using random-effects modelling. Fifteen trials that randomized a total of 8737 participants were included for the analysis. None of the trials was classified as low risk of bias. The use of thromboelastography- (TEG®) or thromboelastometry (ROTEM®)-guided algorithms did not reduce mortality [risk ratio (RR) 0.55, 95% confidence interval (CI) 0.28-1.10] without heterogeneity (I2=1%), reoperation for bleeding, stroke, ventilation time, or hospital length of stay compared with standard care. Use of TEG® or ROTEM® resulted in reductions in the frequency of red blood cell (Risk Ratio 0.88, 95% Confidence Interval 0.79-0.97; I2=43%) and platelet transfusion (Risk Ratio 0.78, 95% Confidence Interval 0.66-0.93; I2=0%). Group Reading Assessment and Diagnostic Evaluation (GRADE) assessment demonstrated that the quality of the evidence was low or very low for all estimated outcomes. Routine use of viscoelastic point-of-care tests did not improve important clinical outcomes beyond transfusion in adults undergoing cardiac surgery.