Recombinant Factor VIIa Is Associated With Increased Thrombotic Complications in Pediatric Cardiac Surgery Patients

Recombinant factor VIIa (rFVIIa) is routinely used as an off-label hemostatic agent in children undergoing cardiac surgery. Despite evidence that rFVIIa use is associated with an increased incidence of thrombotic complications in adult cardiac surgery, the safety of rFVIIa as a rescue hemostatic agent in the pediatric cardiac surgical population is less definitively delineated. In this retrospective study, we used propensity score matching to compare the incidence of thrombotic complications between children treated with rFVIIa and their matched controls.

We retrospectively reviewed medical records and pharmacy data from all neonates and children who underwent congenital cardiac surgery between May 1, 2011, and October 31, 2013, at Boston Children's Hospital, and identified those who received rFVIIa during the perioperative period. Using existing knowledge, we chose 10 factors associated with bleeding after cardiac surgery to be used in our propensity score: age, sex, body weight, neonates, prematurity, previous sternotomy, cardiopulmonary bypass time, deep hypothermic circulatory arrest time, aortic cross-clamp time, and the operative surgeon. We then used propensity-matched analysis to match children treated with rFVIIa with 2 controls. The primary outcome was thrombotic complications. Secondary outcomes included reexploration for bleeding, length of cardiac intensive care unit stay, length of hospital stay, and 30-day mortality.

One hundred forty-nine patients received perioperative rFVIIa during the study period. Propensity matching yielded 143 rFVIIa patients matched to 2 control patients each (n = 286). Three control patients were found to have received rFVIIa during the perioperative course and were removed from the analysis, for a total of 283 control patients. The administration of rFVIIa was associated with an increased incidence of thrombotic complications (20% vs 8%; odds ratio [OR]: 3.9 [95% confidence interval {CI}: 2.6-5.9], P < .001). Administration of rFVIIa was associated with a prolonged median length of cardiac intensive care unit stay (8 days [interquartile range {IQR}: 4-24] vs 5 days [IQR: 2-10], P < .001) and prolonged length of hospital stay (20 [IQR: 9-44] vs 11 days [IQR: 7-23], P < .001). No difference in reexploration for bleeding (rFVII = 14% vs controls = 9%; OR: 1.7 [95% CI, 0.92-3.1], P = .12) or 30-day mortality was observed (8% vs 6%; OR 1.3 [95% CI, 0.60-2.89], P = .51).

This retrospective analysis confirmed that perioperative administration of rFVIIa is associated with an increased incidence of postoperative thrombotic complications in neonates and children undergoing cardiac surgery, without increase in 30-day mortality. In conclusion, rFVIIa should be used with extreme caution in pediatric patients undergoing cardiac surgery.