Efficacy and safety of recombinant factor XIII on reducing blood transfusions in cardiac surgery: a randomized, placebo-controlled, multicenter clinical trial.

OBJECTIVES: Cardiac surgery with cardiopulmonary bypass frequently leads to excessive bleeding, obligating blood product transfusions. Because low factor XIII (FXIII) levels have been associated with bleeding after cardiac surgery, we investigated whether administering recombinant FXIII after cardiopulmonary bypass would reduce transfusions.

METHODS: In this double-blinded, placebo-controlled, multicenter trial, 409 cardiac surgical patients at moderate risk for transfusion were randomized to receive an intravenous dose of recombinant FXIII, 17.5 IU/kg (n = 143), 35 IU/kg (n = 138), or placebo (n = 128) after cardiopulmonary bypass. Transfusion guidelines were standardized. The primary efficacy outcome was avoidance of allogeneic blood products for 7 days postsurgery. Secondary outcomes included amount of blood products transfused and reoperation rate. Serious adverse events were measured for 7 weeks.

RESULTS: Study groups had comparable baseline characteristics and an approximately 40% decrease in FXIII levels after cardiopulmonary bypass. Thirty minutes postdose, FXIII levels were restored to higher than the lower 2.5th percentile of preoperative activity in 49% of the placebo group, and 85% and 95% of the 17.5- and 35-IU/kg recombinant FXIII groups, respectively (P < .05 for both treatments vs placebo). Transfusion avoidance rates were 64.8%, 64.3%, and 65.9% with placebo, 17.5 IU/kg, and 35 IU/kg recombinant FXIII (respective odds ratios against placebo, 1.05 [95% confidence interval, 0.61-1.80] and 0.99 [95% confidence interval, 0.57-1.72]). Groups had comparable adverse event rates.

CONCLUSIONS: Replenishment of FXIII levels after cardiopulmonary bypass had no effect on transfusion avoidance, transfusion requirements, or reoperation in moderate-risk cardiac surgery patients (ClinicalTrials.gov identifier: NCT00914589).