Impact of Early, Low-Dose Factor VIIa on Subsequent Transfusions and Length of Stay in Cardiac Surgery

Factor Eight Inhibitor Bypass Activity Use in Cardiac Surgery: A Propensity-matched Analysis of Safety Outcomes

BACKGROUND

Bleeding during cardiac surgery may be refractory to standard interventions. Off-label use of factor eight inhibitor bypass activity (FEIBA) has been described to treat such bleeding. However, reports of safety, particularly thromboembolic outcomes, show mixed results, and reported cohorts have been small.

METHODS

Adult patients undergoing cardiac surgery on cardiopulmonary bypass between July 1, 2018, and June 30, 2023, at Stanford Hospital (Stanford, California) were reviewed (n = 3,335). Patients who received FEIBA to treat postcardiopulmonary bypass bleeding were matched with those who did not by propensity scores in a 1:1 ratio using nearest neighbor matching (n = 352 per group). The primary outcome was a composite outcome of thromboembolic complications including any one of deep vein thrombosis, pulmonary embolism, unplanned coronary artery intervention, ischemic stroke, and acute limb ischemia, in the postoperative period. Secondary outcomes included renal failure, reoperation, postoperative transfusion, intensive care unit length of stay, and 30-day mortality.

RESULTS

A total of 704 encounters was included in this propensity-matched analysis. The mean dose of FEIBA administered was 7.3 ± 5.5 U/kg. In propensity-matched multivariate logistic regression models, there was no statistically significant difference in odds ratios for thromboembolic outcomes, intensive care unit length of stay, or mortality. Patients who received more than 750 U FEIBA had an increased odds ratio for acute renal failure (odds ratio, 4.14; 95% CI, 1.61 to 10.36; P < 0.001). In multivariate linear regression, patients receiving FEIBA were transfused more plasma and cryoprecipitate postoperatively. However, only the dose range of 501 to 750 U was associated with an increase in transfusion of erythrocytes (β, 2.73; 95% CI, 0.68 to 4.78; P = 0.009) and platelets (β, 1.74; 95% CI, 0.85 to 2.63; P < 0.001).

CONCLUSIONS

Low-dose FEIBA administration during cardiac surgery does not increase risk of thromboembolic events, intensive care unit length of stay, or mortality in a propensity-matched cohort. Higher doses were associated with increased acute renal failure and postoperative transfusion. Further studies are required to establish the efficacy of activated factor concentrates to treat refractory bleeding during cardiac surgery.

EDITOR’S PERSPECTIVE

Comparison of Low Dose Recombinant Factor VIIa and 4-Factor Prothrombin Complex Concentrate for Treatment of Bleeding Related to Cardiac Surgery

Background: Recombinant factor VIIa (rFVIIa) and prothrombin concentrate complex (PCC) are used for uncontrolled bleeding in cardiac surgery (CS), however, there are limited direct comparisons of these agents. Objective: To evaluate the efficacy and safety of rFVIIa and PCC in CS related bleeding. Methods: This retrospective study included adult CS patients who received either low dose rFVIIa (<30 mcg/kg) or 4-factor PCC. The primary outcome was transfusion requirements of packed red blood cells (pRBC) within 6 hours of factor administration. Secondary efficacy outcomes included transfusion requirements 0-18 hours, doses of additional factor product, thrombotic events, and acute kidney injury (AKI). Results: A total of 179 patients were included (n = 78 rFVIIa; n = 101 PCC). Of patients who received blood products, there was no difference in the requirement of pRBCs within 6 hours (73.8 vs 68.9%, P = .5359) or in the median amount of pRBC transfused (500 mL vs 640 mL, P = .0723) in the rFVIIa and PCC groups respectively. Patients in the PCC group were more likely to require additional factor products (24.4% vs 47.5%, P = .0015), develop AKI (12.8% vs 25.7%, P = .0325), have longer ICU lengths of stay [2 (IQR 1-5) vs 4 (IQR 2-6), P = .0487] and greater in-hospital mortality (2.6% vs 10.9%, P = .033). There was no difference in thrombotic events. Conclusion: Although, there was no difference in pRBC transfusion requirements between PCC and rFVIIa, more patients in the PCC group required additional factor products and had increased adverse effects. Further comparisons of PCC and rFVIIa are warranted.

The Year in Coagulation and Transfusion: Selected Highlights from 2022

This is an annual review to cover highlights in transfusion and coagulation in patients undergoing cardiovascular surgery. The goal of this article is to provide readers with a focused summary of the most important transfusion and coagulation topics published in 2022. This includes a discussion covering the management of anemia and red blood cell transfusion, the management of factor Xa inhibitors, updates in coagulation testing, updates in the use of factor concentrates, advances in platelet therapy, advances in anticoagulation management of patients on extracorporeal membrane oxygenation and other forms of mechanical circulatory support, and advances in the diagnosis and management of heparin-induced thrombocytopenia.

Undiagnosed Factor VII Deficiency in Cardiac Surgery Complicated by Bleeding: A Case Report

Rare bleeding disorders in the perioperative period call for targeted resuscitation strategies. Factor VII deficiency, for instance, is often corrected with exogenous administration of recombinant factor VIIa. This activated clotting factor, initially designed for patients with hemophilia A or B with factor inhibitors, is gaining popularity as a salvage therapy for severe and persistent traumatic and surgical bleeding. This article describes the management of a cardiothoracic surgical patient with undiagnosed isolated factor VII deficiency who experienced significant postoperative bleeding which subsided after the administration of recombinant factor VIIa. In this case, EXTEM failed to detect a clotting factor deficiency.

Off-label Use of Recombinant Activated Factor VII for Cardiac Surgical Bleeding

Recombinant activated factor VII has been widely used in an off-label manner for cardiac surgical bleeding. Recent reports have administered recombinant activated factor VII earlier in the course of bleeding and at lower doses than initially reported. This review will discuss the history, mechanism, current recommendations for use, and recent data on the use of recombinant activated factor VII in cardiac surgical bleeding.