Rapid reversal of warfarin-associated hemorrhage in the emergency department by prothrombin complex concentrates

Novel strategies in antithrombotic therapy: targeting thrombosis while preserving hemostasis

Antithrombotic therapy is a delicate balance between the benefits of preventing a thrombotic event and the risks of inducing a major bleed. Traditional approaches have included antiplatelet and anticoagulant medications, require careful dosing and monitoring, and all carry some risk of bleeding. In recent years, several new targets have been identified, both in the platelet and coagulation systems, which may mitigate this bleeding risk. In this review, we briefly describe the current state of antithrombotic therapy, and then present a detailed discussion of the new generation of drugs that are being developed to target more safely existing or newly identified pathways, alongside the strategies to reverse direct oral anticoagulants, showcasing the breadth of approaches. Combined, these exciting advances in antithrombotic therapy bring us closer than we have ever been to the "holy grail" of the field, a treatment that separates the hemostatic and thrombotic systems, preventing clots without any concurrent bleeding risk.

Clinical utilization of four-factor prothrombin complex concentrate: a retrospective single center study

OBJECTIVE

Four-factor prothrombin complex concentrate (4F-PCC) was approved by the US Food and Drug Administration in 2013 for management of severely bleeding patients on warfarin therapy. We describe use of 4F-PCC at a large, suburban academic center.

METHODS

We retrospectively reviewed all patients receiving 4F-PCC from its introduction through 2016 at a large level 1 trauma center. Clinical and demographic data were obtained, including indications for anticoagulation and antiplatelet agents, comorbidities, concomitant medications, etiology and site of bleeding, as well as disposition, length of stay, mortality, and thrombotic events.

RESULTS

One hundred eighty-four patients received 4F-PCC. Mean age was 72 years; 40.8% were female. Indications for 4F-PCC administration included: active bleeding (74%), reversal prior to a procedure (14%), and elevated international normalized ratio (12%). Warfarin was the most common concomitant medication (71.1%). Most patients were receiving anticoagulation for atrial fibrillation (63%). Concomitant treatments for bleeding included vitamin K (58.2%), packed red blood cells (50%), fresh frozen plasma (38%), and platelets (26.1%), amongst others. Median length of hospital stay was 8.4 days. Nine patients (4.9%) developed thrombosis within 90 days of 4F-PCC. Mortality was 24.5%, with notably higher rates amongst those who received 4F-PCC for off-label indications (19.1% on-label mortality vs. 37.7% off-label mortality on chi-square analysis, P=0.01).

CONCLUSION

This study demonstrates that 4F-PCC is being utilized for indications other than the reversal of warfarin-induced coagulopathy. Further investigation is warranted to determine the efficacy and safety of 4F-PCC for these potential indications.

Emergency Reversal of Anticoagulation

Owing to the propensity of anticoagulated patients to bleed, a strategy for reversal of anticoagulation induced by any of the common agents is essential. Many patients are anticoagulated with a variety of agents, including warfarin, low molecular weight heparin, and the direct oral anticoagulants such as factor Xa and factor IIa inhibitors. Patients may also be using antiplatelet agents. Recommendations to reverse bleeding in these patients are constantly evolving with the recent development of specific reversal agents. A working knowledge of hemostasis and the reversal of anticoagulation and antiplatelet drugs is required for every emergency department provider. This article reviews these topics and presents the currently recommended strategies for dealing with bleeding in the anticoagulated patient.

Protocolized use of Factor Eight Inhibitor Bypassing Activity (FEIBA) for the reversal of warfarin induced coagulopathy

INTRODUCTION

Coagulopathy due to warfarin in patients with major bleeding was traditionally reversed with fresh frozen plasma and intravenous (IV) vitamin K, but prothrombin complex concentrates (PCC) are increasingly used in the treatment of these patients. Factor Eight Inhibitor Bypassing Activity (FEIBA) is an activated four-factor PCC most commonly used in patients with hemophilia. We aimed to evaluate the efficacy and safety of FEIBA and IV vitamin K for the reversal of warfarin-associated coagulopathy in patients with major bleeding, by measuring the percentage of patients who achieved target INR ≤ 1.5 and the incidence of thrombotic adverse events (TAE).

METHODS

In this prospective observational study, we enrolled patients presenting to the Emergency Department (ED) with warfarin associated coagulopathy (INR > 1.5) and major bleeding. Patients received FEIBA using an INR based dosing strategy and IV vitamin K.

RESULTS

In 43 patients, median initial INR was 4.0 (2.7, 7.3 interquartile range (IQR)). Median time to result the second INR was 45 min (38, 55 IQR) and the median INR was 1.4 (1.3, 1.6 IQR). Out of the 43 patients, 93% achieved the target INR of ≤1.5. In-hospital mortality was 40% (17 patients). There were 11 TAEs in 6 patients (14%); 4 events in 2 patients (5%) were attributed to FEIBA.

CONCLUSION

A protocolized use of FEIBA and IV vitamin K resulted in the efficacious reversal of warfarin-induced coagulopathy in patients with major bleeding. TAEs occurred in 14% of patients and were attributed to FEIBA in 5% of patients.

Effectiveness of four-factor prothrombin complex concentrates versus plasma on vitamin K antagonist associated plasma international normalized ratio reversal: a systematic review protocol

REVIEW QUESTION

The question of this review is: what is the effectiveness of Kcentra/Beriplex/Confidex compared to plasma for international normalized ratio (INR) reduction in adult patients (18 years and over) on any vitamin K antagonist therapy?

Dose-associated pulmonary complication rates after fresh frozen plasma administration for warfarin reversal

ESSENTIALS: Fresh frozen plasma (FFP) may be associated with a dose-based risk of pulmonary complications. Patients received FFP for warfarin reversal at a large academic hospital over a 3-year period. Almost 20% developed pulmonary complications, and the risk was highest after > 3 units of FFP. The risk of pulmonary complications remained significant in multivariable analysis.

BACKGROUND

Fresh frozen plasma (FFP) is often administered to reverse warfarin anticoagulation. Administration has been associated with pulmonary complications, but it is unclear whether this risk is dose-related. Aims We sought to characterize the incidence and dose relationship of pulmonary complications, including transfusion-associated circulatory overload (TACO) and transfusion-related acute lung injury (TRALI), after FFP administration for warfarin reversal.

METHODS

We performed a structured retrospective review of patients who received FFP for warfarin reversal in the emergency department (ED) of an academic tertiary-care hospital over a 3-year period. Logistic regression was used to explore the relationship between FFP dose and risk of pulmonary events.

RESULTS

Two hundred and fifty-one patients met the inclusion criteria. Overall, 49 patients (20%) developed pulmonary complications, including 30 (12%) with TACO, two (1%) with TRALI, and 17 (7%) with pulmonary edema not meeting the criteria for TACO. Pulmonary complications were significantly more frequent in those who received > 3 units of FFP (34.0% versus 15.6%, 95% confidence interval for risk difference 7.9%-8.9%). After stratification by subtype of complication, only the risk of TACO was statistically significant (28.3% versus 7.6%, 95% confidence interval for risk difference 8.2%-16.6%). In multivariable analysis controlling for age, sex, initial systolic blood pressure, and intravenous fluids given in the ED, > 3 units of FFP remained a significant risk factor for pulmonary complications (odds ratio 2.49, 95% confidence interval 1.21-5.13).

CONCLUSIONS

Almost 20% of patients who received FFP for warfarin reversal developed pulmonary complications, primarily TACO, and this risk increased with > 3 units of FFP. Clinicians should be aware of and prepared to manage these complications.

Use and effectiveness of prothrombin complex concentrate in an emergency department: a review of 15 cases

Aim

Hemostatic management of patients on oral anticoagulant therapy with critical bleeding continues to be a major challenge. The present study aimed to validate the efficacy, safety, and optimal dosage of prothrombin complex concentrate for rapidly normalizing elevated international normalized ratio (INR) values and achieving control of hemorrhage at an emergency department in Japan.

Methods

We retrospectively collected data from all patients who were treated with PCC at our emergency department between January 2013 and September 2014. We used a commercially available prothrombin complex concentrate.

Results

Fifteen patients (male / female, 7/8; average, 71.4 years) received prothrombin complex concentrate (14 for bleeding, including trauma-related bleeding, and one for invasive intervention) without complications. All but one patient received warfarin and the INR value declined in all patients with 500 IU (average, 8.98 IU/kg) prothrombin complex concentrate (average INR value before and after treatment: 2.20 versus 1.26). Although two patients died because of multiple organ failure, a relatively satisfactory hemostatic response was obtained in at least 11/15 patients. However, patients with a baseline INR value above 2.5 never achieved an optimal response (INR value < 1.35).

Conclusion

A single dose of 500 IU prothrombin complex concentrate is insufficient for normalization of INR value, especially in patients with prolonged INR values. Administration strategies for trauma, the ideal dose (e.g., higher than 500 IU/patient), target optimal INR values, as well as the confirmation of safety should be addressed in the future. Further clinical trials are warranted to confirm this preliminary report.

Oral anticoagulants and status of antidotes for the reversal of bleeding risk

Anticoagulants have been used in clinical practice for more than 50 years. Their indications expand, as more people are diagnosed each year with atrial fibrillation and venous thromboembolism. Vitamin K antagonists have been the most popular choice due to their effectiveness and their ability to reverse bleeding using a known antidote; oral and intravenous vitamin K have long been known to reverse the effects of warfarin. With new classes of anticoagulants making their way onto the market, such as factor Xa inhibitors (rivaroxaban, apixaban) and direct thrombin inhibitors (dabigatran), the need for new reversal agents is paramount. Patients tend to be more receptive to these medications because they do not require routine blood monitoring, can be used at fixed doses, and do not have major drug or food interactions. Antidotes for these medications have shown promise in animal models and are currently in clinical trials.