The FIBTEM paradox: Do coronary artery bypass grafting patients with high baseline FIBTEM clot firmness need more allogeneic blood transfusion?

BACKGROUND

Fibrinogen thromboelastometry (FIBTEM) test is clinically used for rotational thromboelastometry as a surrogate measure of fibrinogen. Elevated fibrinogen might confer protection against bleeding after major surgery. This single-center study was conducted to assess any relationship between baseline FIBTEM value and exposure to allogeneic transfusion in patients undergoing coronary artery bypass grafting (CABG).

STUDY DESIGN AND

METHODS

Data were obtained retrospectively from local FIBTEM data and the Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database between 2016 and 2019. Preoperative FIBTEM 10-min amplitude (A10) was categorized as low (≤ 18 mm), intermediate (19-23 mm), or high (≥24 mm). The primary outcome was any transfusion during the hospitalization, including red blood cells (RBCs), platelets, plasma, and cryoprecipitate. A multivariable regression model was used to adjust for confounders and calculate an odds ratio (OR) for any transfusion.

RESULTS

The high FIBTEM group included more female and African-American patients, as well as urgent surgery. The STS predicted risks of morbidity and mortality were greater, and anemia was most prevalent with high FIBTEM. Unadjusted blood transfusion rates were increased with high FIBTEM due to RBC transfusion, but non-RBC transfusion was highest with low FIBTEM. After adjustments, a lower OR for transfusion was associated with high FIBTEM (0.426; 95% confidence interval, 0.199-0.914) compared to low FIBTEM.

CONCLUSION

The high FIBTEM group frequently presented with anemia and comorbidities, and received more RBCs but not non-RBC products. Postoperative blood loss was less with high FIBTEM, and after adjustments, it conferred protection against any transfusion.