Effect of In Vivo Administration of Fibrinogen Concentrate Versus Cryoprecipitate on Ex Vivo Clot Degradation in Neonates Undergoing Cardiac Surgery

BACKGROUND: Neonates undergoing cardiac surgery require fibrinogen replacement to restore hemostasis after cardiopulmonary bypass (CPB). Cryoprecipitate is often the first-line treatment, but recent studies demonstrate that fibrinogen concentrate (RiaSTAP; CSL Behring) may be acceptable in this population. This investigator-initiated, randomized trial compares cryoprecipitate to fibrinogen concentrate in neonates undergoing cardiac surgery (ClinicalTrials.gov NCT03932240). The primary end point was the percent change in ex vivo clot degradation from baseline at 24 hours after surgery between groups. Secondary outcomes included intraoperative blood transfusions, coagulation factor levels, and adverse events. METHODS: Neonates were randomized to receive cryoprecipitate (control group) or fibrinogen concentrate (study group) as part of a post-CPB transfusion algorithm. Blood samples were drawn at 4 time points: presurgery (T1), after treatment (T2), arrival to the intensive care unit (ICU) (T3), and 24 hours postsurgery (T4). Using the mixed-effect models, we analyzed the percent change in ex vivo clot degradation from a patient’s presurgery baseline at each time point. Intraoperative blood product transfusions, coagulation factor levels, perioperative laboratory values, and adverse events were collected. RESULTS: Thirty-six neonates were enrolled (intent to treat ITT). Thirteen patients in the control group and seventeen patients in the study group completed the study per protocol (PP). After normalizing to the patient’s own baseline (T1), no significant differences were observed in clot degradation at T2 or T3. At T4, patients in the study group had greater degradation when compared to those in the control group (826.5%, 95% confidence interval CI, 291.1–1361.9 vs −545.9%, 95% CI, −1081.3 to −10.4; P < .001). Study group patients received significantly less median post-CPB transfusions than control group patients (ITT, 27.2 mL/kg 19.0–36.9 vs 41.6 29.2–52.4; P = .043; PP 26.7 mL/kg 18.8–32.2 vs 41.2 mL/kg 29.0–51.4; P < .001). No differences were observed in bleeding or thrombotic events. CONCLUSIONS: Neonates who received fibrinogen concentrate, as compared to cryoprecipitate, have similar perioperative ex vivo clot degradation with faster degradation at 24 hours postsurgery, less post-CPB blood transfusions, and no increased bleeding or thrombotic complications. Our findings suggest that fibrinogen concentrate adequately restores hemostasis and reduces transfusions in neonates after CPB without increased bleeding or thrombosis risk.