A Randomized Controlled Trial Comparing Effectiveness of Different Fibrinogen Preparations in Restoring Clot Firmness.

Background: Different preparations of fibrinogen concentrate are currently available. Two in vitro studies demonstrated the superiority of FibCLOT (LFB) in increasing clot firmness with respect to RiaSTAP (CSL Behring). The present trial involved a clinical model to test the hypothesis of superiority, with the increase in clot firmness as the primary end point.

Methods: Forty cardiac surgery patients were randomly allocated to receive a dose of 30 mg/kg FibCLOT or RiaSTAP after protamine administration in the presence of microvascular bleeding and a FIBTEM maximum clot firmness (MCF) <10 mm. Viscoelastic parameters were measured before and after fibrinogen supplementation: FIBTEM MCF, EXTEM MCF, and EXTEM clotting time (CT).

Results: The mean increase in FIBTEM MCF was 4 ± 1.2 mm (mean and standard deviation) in the FibCLOT group and 4 ± 1.6 mm in the RiaSTAP group ( P = 1.000); the mean decrease in CT was 11. 2 ± 12.2 (mean and standard deviation) seconds in the FibCLOT group and 14. 8 ± 13 seconds in the RiaSTAP group ( P = .372). In both groups, fibrinogen supplementation induced a significant ( P = .001) increase in the FIBTEM MCF and EXTEM CT. The proportions of patients who did not experience an increase of 4 mm in the RiaSTAP group and the FibCLOT group were not statistically significantly higher (35% vs 20%, respectively, relative risk 2.15, 95% confidence interval 0.52-9.00, P = .288).

Conclusions: In contrast to previous in vitro studies, we found that the effect of FibCLOT on MCF and CT was not significantly greater than that of RiaSTAP in cardiac surgery patients. Further studies in other clinical settings are warranted.