Thrombotic complications following the administration of high-dose prothrombin complex concentrate for acute warfarin reversal

Hemostatic Efficacy and Safety of Weight-Based Versus Fixed-Dose 4F-PCC for Vitamin K Antagonist Reversal

Background: Four-factor prothrombin complex concentrate (4F-PCC) is indicated for vitamin K antagonist (VKA) reversal but is associated with thrombotic events (TE). In 2018, the institution revised 4F-PCC dosing for VKA reversal from INR and weight-based dosing to a fixed-dose of 1500 units. Objective: The purpose of this study was to compare hemostatic efficacy and TE rate of fixed-dose 4PCC to weight-based dosing. Methods: This was a retrospective, single-center, quasi-experimental study of adult patients who received 4F-PCC for VKA reversal from January 2014 through May 2016 (INR and weight-based dosing) or April through October 2018 (fixed-dosing). The primary endpoint was hemostatic efficacy, defined by achieving an INR of ≤1.4, or an INR of ≤1.7 with evidence of hemostasis. The key secondary endpoint was TE within 14 days of 4F-PCC administration. Data were analyzed using descriptive statistics, chi-squared for nominal data and Mann-Whitney U for ordinal and continuous data. Results: The study included 163 patients who received weight-based dosing and 45 who received fixed-dose 4F-PCC. Hemostatic efficacy was 76.9% of patients in the weight-based group and 77.4% of patients in the fixed-dose group (P = .229). TE occurred in 13.5% of the weight-based vs 6.7% of the fixed-dose group (P = .181). Conclusion: This study found no difference in hemostatic efficacy with fixed-dose 4F-PCC for VKA reversal compared to INR and weight-based dosing. The occurrence of TE was reduced by 50% with the 4F-PCC fixed-dose strategy; however, this difference was not statistically significant. Further randomized studies are needed to confirm these results.

Fixed-dose prothrombin complex concentrate for emergent warfarin reversal among patients with intracranial hemorrhage

INTRODUCTION

Four-factor prothrombin complex concentrate (4PCC) is the preferred reversal agent for warfarin reversal, although the ideal dose is unknown. Fixed-dose 4PCC offers simplified dosing compared to standard-dosing algorithms with potentially lower risks of thromboembolic complications given lower doses are typically utilized.

METHODS

Retrospective, observational, multicentered, pre- post- study of patients who received 4PCC for warfarin reversal among four hospitals within the same regional health system. Standard-dose patients received variable doses ranging from 25 to 50 units/kg based on total body weight and initial INR and fixed-dose patients received 2000 units. The primary outcome was achievement of a target INR ≤ 1.4 on the first post-4PCC INR result.

RESULTS

After exclusions, 48 and 42 patients were analyzed in the standard-dose and fixed-dose groups, respectively. There was no difference in the ability to achieve a target INR of ≤1.4 (82.6% vs 81.5%, p = 0.14). Both groups received the same median dose of 2000 units, although fixed-dose patients actually received a higher weight-based dose than standard-dose patients (27 units/kg vs 24.5 units/kg).

CONCLUSION

A fixed-dose 4PCC regimen of 2000 units among patients with ICH was as effective as standard-dose 4PCC for INR reversal among patients with ICH. However, fixed-doses of 2000 units at times exceeded standard 4PCC doses which may be contradictory to the goals of fixed-dose 4PCC for warfarin reversal.

Comparison of 3 Different Prothrombin Complex Concentrate Regimens for Emergent Warfarin Reversal: PCCWaR Study

BACKGROUND

The ideal dose and specific prothrombin complex concentrate (PCC) for warfarin reversal is unknown.

OBJECTIVE

To evaluate the reduction in international normalized ratio (INR) of 3 different PCC dosing regimens: fixed-dose activated 4-factor PCC (aPCC), fixed-dose 4-factor PCC (4PCC), and standard-dose 4PCC.

METHODS

This was a multicenter retrospective cohort review. Patients >18 years of age who received PCC for warfarin reversal between January 1, 2017, and December 31, 2017, were screened for inclusion. Patients were excluded if they did not receive the correct PCC dosing regimen, received PCC for nonwarfarin bleeding, had a baseline INR less than 2, or received a massive transfusion protocol. Two institutions utilized aPCC dosed at 500 IU for INR <5 and 1000 IU for INR ≥5. Two institutions utilized fixed-dose 4PCC at 1500 to 2000 units depending on patient factors. Two institutions utilized 4PCC package insert dosing. The primary outcome was achievement of post-PCC target INR ≤1.4. Secondary outcomes included percentage change in INR, lowest 24-hour INR, and mortality.

RESULTS

A total of 154 patients were included (fixed-dose aPCC: n = 29; fixed-dose 4PCC: n = 53; standard-dose 4PCC: n = 72). There was no statistical difference between groups in achieving the primary outcome (58.6% vs 69.8% vs 79.2%, respectively; P = 0.103) or any secondary outcomes.

CONCLUSION AND RELEVANCE

There was no difference in the ability to achieve a post-PCC INR of ≤1.4 between 3 different PCC regimens for warfarin reversal. Additional research is warranted to determine the ideal dose and PCC agent for warfarin reversal.

Activated Prothrombin Complex Concentrate Versus 4-Factor Prothrombin Complex Concentrate for Vitamin K-Antagonist Reversal

OBJECTIVES

To compare the international normalized ratio normalization efficacy of activated prothrombin complex concentrates and 4-factor prothrombin complex concentrates and to evaluate the thrombotic complications in patients treated with these products for warfarin-associated hemorrhage.

DESIGN

Retrospective, Multicenter Cohort.

SETTING

Large, Community, Teaching Hospital.

PATIENTS

Patients greater than 18 years old and received either activated prothrombin complex concentrate or 4-factor prothrombin complex concentrate for the treatment of warfarin-associated hemorrhage. We excluded those patients who received either agent for an indication other than warfarin-associated hemorrhage, pregnant, had a baseline international normalized ratio of less than 2, received a massive transfusion as defined by hospital protocol, received plasma for treatment of warfarin-associated hemorrhage, or were treated for an acute warfarin ingestion.

INTERVENTIONS

Patients in the activated prothrombin complex concentrate group (enrolled from one hospital) with an international normalized ratio of less than 5 received 500 IU and those with an international normalized ratio greater than 5 received 1,000 IU. Patients in the 4-factor prothrombin complex concentrate (enrolled from a separate hospital) group received the Food and Drug Administration approved dosing algorithm.

MEASUREMENTS AND MAIN RESULTS

A total of 158 patients were included in the final analysis (activated prothrombin complex concentrate = 118; 4-factor prothrombin complex concentrate = 40). Those in the 4-factor prothrombin complex concentrate group had a higher pretreatment international normalized ratio (2.7 ± 1.8 vs 3.5 ± 2.9; p = 0.0164). However, the posttreatment international normalized ratio was similar between the groups. In addition, even when controlling for differences in the pretreatment international normalized ratio, there was no difference in the ability to achieve a posttreatment international normalized ratio of less than 1.4 (odds ratio, 0.753 [95% CI, 0.637-0.890]; p = 0.0009). Those in the activated prothrombin complex concentrate group did have higher odds of achieving a posttreatment international normalized ratio of less than 1.2 (odds ratio, 3.23 [95% CI, 1.34-7.81]; p = 0.0088). There was only one posttreatment thrombotic complication reported.

CONCLUSIONS

A low, fixed dose of activated prothrombin complex concentrate was as effective as standard dose 4-factor prothrombin complex concentrate for normalization of international normalized ratio. In addition, we did not see an increase in thrombotic events.

Low-dose compared to manufacturer-recommended dose four-factor prothrombin complex concentrate for acute warfarin reversal

BACKGROUND

Four-factor PCC is the recommended standard of care for acute warfarin reversal but optimal dosing is unknown. We aim to show that a low-dose strategy is often adequate and may reduce the risk of thromboembolic events when compared to manufacturer-recommended dosing.

METHODS

A weight-based dosing strategy of 15-25 units/kg was established as the institutional standard of care in May 2015. This retrospective, before-and-after cohort analysis included patients receiving 4F-PCC according to a manufacturer-recommended (n = 122) or a low-dose (n = 83) strategy. The primary efficacy outcome was a combination of INR reversal on first check and hemostatic efficacy at 24 h.

RESULTS

Demographics, indications for warfarin, and presenting INR values were similar between the two groups. Patients in the manufacturer-recommended dose group received significantly more 4F-PCC than the low dose group (2110 units vs. 1530 units). More patients in the manufacturer-recommended dose group achieved the primary endpoint (75.4% vs. 61.4%), with more patients achieving the target INR on recheck in the manufacturer-recommended dose group (95.9% vs. 84.3%) and no difference in hemostatic efficacy between groups (79.5% vs. 74.7%). There was no difference in thromboembolic events at 72 h (4.1% vs. 1.2%) or at 30 days (8.2% vs. 4.8%). Significantly more patients in the manufacturer-recommended dose group died or were transferred to hospice care during hospitalization (21.3% vs. 9.6%).

CONCLUSION

Utilization of a low-dose 4F-PCC strategy resulted in fewer patients achieving target INR reversal, but no difference in hemostatic efficacy, thromboembolic events, or survival.

Fixed-Dose Four-Factor Prothrombin Complex Concentrate for Vitamin K Antagonist Reversal: Does One Dose Fit All?

Four-factor prothrombin complex concentrate (4F-PCC) has emerged as the preferred option for emergent reversal of vitamin K antagonists (VKAs); however, the optimal dosing strategy is unknown. Although several studies have attempted to determine the optimal dose of 4F-PCC using a variety of dosing regimens, no dosing strategy has been found to be superior. Many of these studies have evaluated a low, fixed dose of 4F-PCC rather than individualized dosing as recommended in product labeling. The purpose of this review was to evaluate the efficacy and safety of various fixed-dose strategies of 4F-PCC for emergent VKA reversal and to assess limitations of the existing literature. A search of the PubMed database was performed from the earliest available date through 2018 for relevant articles describing fixed-dose 4F-PCC for VKA reversal. Reference lists of relevant articles were also manually reviewed. Most currently available studies are primarily observational and heterogeneous in design. A very low fixed dose of 500 IU is likely inadequate for successful VKA reversal, but increased fixed doses of 1000-1500 IU have found some degree of success and may be considered for VKA reversal. However, many of these studies consistently identified a trend toward international normalized ratio (INR) reversal failure in patients presenting with high baseline INR values or intracranial hemorrhage, suggesting that higher 4F-PCC doses are needed in these patients. Available studies are underpowered to determine whether a dose-dependent association with thrombotic risk exists. Additional large, randomized studies are needed to determine the optimal dosing strategy and ascertain the role for fixed-dose 4F-PCC.

Fixed-dose 4-factor prothrombin complex concentrate: we don't know where we're going if we don't know how to get there

4-Factor Prothrombin Complex Concentrate (4F-PCC) is the standard-of-care intervention in patients with major bleeding taking oral vitamin K antagonists. Despite growing clinical experience with 4-FPCC, the optimal dosing strategy remains unclear. In balancing efficacy, safety, and cost of this treatment, many institutions have adopted a low, fixed-dose regimen, with average doses lower than that in the package insert. The fixed-dose 4F-PCC strategy is supported by the available observational studies and case reports; however, the current body of literature is highly heterogenous. The purpose of this narrative review is to address the advantages and shortcomings with clinical use of fixed-dose 4F-PCC, as well as limitations of the available literature. The heterogeneity of the current literature should guide future studies to support or refute this potentially life-saving intervention.

Low-dose Prothrombin Complex Concentrate for Warfarin-Associated Intracranial Hemorrhage with INR Less Than 2.0

BACKGROUND

Prothrombin complex concentrates (PCCs) have become the first-line therapy for warfarin reversal in the setting of central nervous system (CNS) hemorrhage. Randomized, controlled studies comparing agents for warfarin reversal excluded patients with international normalized ratio (INR) <2, yet INR values of 1.6-1.9 are also associated with poor outcomes.

METHODS

We retrospectively reviewed our use of a low-dose (15 units/kg) strategy of 4-factor PCC (4F-PCC) on warfarin reversal (INR 1.6-1.9) in the setting of both traumatic and spontaneous intracranial bleeding.

RESULTS

A total of 21/134 (15.7%) patients with either spontaneous or traumatic intracranial hemorrhage presented with an INR value of 1.6-1.9. Nine patients (43%) presented with traumatic bleeding and 12 (57%) with spontaneous bleeding. The median (IQR) presenting INR was 1.8 (1.7, 1.9) which decreased to 1.3 (1.2, 1.3) following the administration of low-dose 4F-PCC (median dose = 1062 units; 15.2 units/kg). A total of 19/20 (95%) patients achieved a goal INR value of ≤1.5 on the first check following dosing and 17/20 (85%) achieved an INR value ≤1.3. One patient did not have follow-up INR testing due to withdrawal of life support. No patient experienced hematoma expansion within 48 h of 4F-PCC, and there were no thromboembolic events within 72 h of administration.

CONCLUSIONS

The administration of low dose (15 units/kg) of 4F-PCC for urgent warfarin reversal in the setting of CNS hemorrhage was effective in correcting the INR in patients presenting with INR values of 1.6-1.9. Further assessment of low-dose PCC for urgent reversal of modest INR elevation is warranted.