Prothrombin complex concentrate

Perioperative Management of Direct Oral Anticoagulants in Cardiac Surgery: Practice Recommendations Based on Current Evidence

An increasing number of patients on systemic oral anticoagulants present for cardiac surgery, and cardiac anesthesiologists should be well-informed on their management in the perioperative period. Direct oral anticoagulants (DOACs), including factor Xa inhibitors and direct thrombin inhibitors, are an attractive alternative to warfarin due to fewer dietary and drug interactions, less frequent monitoring requirements, and an improved patient adherence. Since the approval of DOACs by the Food and Drug Administration in 2010, the number of patients on these medications only has increased. The guidelines vary on the periprocedural management of DOACs for cardiac surgery. This review evaluated the current evidence for medication cessation before surgery, based on timing as well as plasma drug concentration. The practice recommendations of various monitoring tests and new evolving point-of-care testing are examined herein. The different reversal agents were discussed by the authors for both elective and urgent procedures. The cardiac anesthesiologist needs to be intimately familiar with the management and current best practices of DOACs for safe and appropriate patient care.

Pharmacologic Agents Used to Reverse the Anticoagulant Effect of Common Anticoagulants

Numerous oral and parenteral anticoagulant drugs are now available for clinical use. Understanding the precise pharmacologic properties of each anticoagulant is imperative for those practitioners who prescribe these drugs, including knowing the current recommendations for reversing the anticoagulant effect of each anticoagulant. This review provides a brief description of the various anticoagulants used today and also discusses the pharmacologic properties of those drugs used to reverse the anticoagulant action of specific anticoagulants.

Inactivated Four-Factor Prothrombin Complex Concentrate Dosing Practices for Reversal of Warfarin-Related Intracranial Hemorrhage

BACKGROUND/OBJECTIVE

Inactivated four-factor prothrombin complex concentrate (I4F-PCC, Kcentra^®) has become an important agent for the urgent or emergent reversal of bleeding associated with vitamin K antagonists such as warfarin. There is recognized inter-institutional variability with the use of I4F-PCC, especially as it relates to dosing practices. We sought to characterize variations in I4F-PCC dosing practices and their impact on patient outcomes and describe overall real-world clinical practice surrounding I4F-PCC utilization in the context of the management of warfarin-related intracranial hemorrhage (ICH).

METHODS

This is a multicenter retrospective pragmatic registry study of adult patients admitted at a participating study site between January 1, 2014, and December 31, 2015, who received I4F-PCC for reversal of warfarin-related ICH. Practices around warfarin-related ICH reversal in context of I4F-PCC utilization are described, including repeat I4F-PCC dosing, adjunctive reversal agents, and dose rounding policies (i.e., rounding doses to nearest vial size vs preparing exact/unrounded doses). All research was approved by local human investigation committees at each institution.

RESULTS

Seventeen institutions contributed data on 528 patients to this registry. These institutions were primarily urban centers (74%), located in the southeast USA (47%), with Level 1 Trauma designation (79%), and with Comprehensive Stroke Center designation (74%). Most patients included in the study had sustained a non-traumatic ICH (68%), had a median admission GCS of 14 (IQR 7-15), and were receiving warfarin for atrial fibrillation (57.4%). There was substantial time latency between baseline INR and I4F-PCC (median 2.4 h, IQR 1.4-4.5 h). Most patients received adjunctive reversal agents, including vitamin K (89.5%) and fresh frozen plasma (FFP) (31.9%). A smaller proportion (6.0%) of patients received repeat I4F-PCC dosing. The median ICU length of stay (LOS) was 3 days (IQR 2-7 days), median hospital LOS was 6 days (IQR 3-12 days), and overall mortality rate was 28.8%. For institutions rounding doses to the nearest vial size, the first post-I4F-PCC dose INR was statistically but not clinically significantly lower than for institutions without vial size dose rounding, with comparable degrees of INR reduction from baseline. No differences were observed between dose rounding cohorts in adverse effects, ICU or hospital LOS, modified Rankin score at discharge, or mortality rates.

CONCLUSIONS

Most patients received single doses of I4F-PCC, with adjunctive reversal agents and rounding doses to vial size. The time difference from baseline INR to factor product administration is a potential opportunity for process improvement in the management of warfarin-related ICH.

Four-Factor Prothrombin Complex Concentrate: An Indispensable Adjunct in Coagulopathy of Trauma Management - A Comparative Review of the Literature over 2 Decades

BACKGROUND

Damage control resuscitation forms the cornerstone of management in trauma surgery. Several blood products have been widely used for preoperative transfusions prior to emergency surgeries and for hemorrhage control in trauma. Prothrombin complex concentrate (PCC) is now being introduced as an essential component of damage control resuscitation.

SUMMARY

We did a comparative descriptive analysis of several single and multi-institutional clinical trials and retrospective cohort studies. The primary focus of these studies was a comparison between PCC and other transfusion modalities including recombinant factor VIIa, fresh-frozen plasma, and fibrinogen based on several vital parameters. The parameters included rapid international normalized ratio reversal, hospital length of stay, cost-effectiveness, mortality rate, and rate of thromboembolic complications.

KEY POINTS

Although still awaiting its approval from the FDA for use in traumatic coagulopathy, 4-factor PCC has shown far more convincing results in contrast to former transfusion modalities, even 3-factor PCC. However, more prospective extensive clinical trials on national levels are needed to compare its effectiveness to 3-factor PCC and gather promising recognition in the trauma care fraternity.

Reversal Agents for the Direct Factor Xa Inhibitors: Biochemical Mechanisms of Current and Newly Emerging Therapies

The direct oral anticoagulants targeting coagulation factor Xa or thrombin are widely used as alternatives to vitamin K antagonists in the management of venous thromboembolism and nonvalvular atrial fibrillation. In case of bleeding or emergency surgery, reversal agents are helpful to counteract the anticoagulant therapy and restore hemostasis. While idarucizumab has been established as an antidote for the direct thrombin inhibitor dabigatran, reversal strategies for the direct factor Xa inhibitors have been a focal point in clinical care over the past years. In the absence of specific reversal agents, the off-label use of (activated) prothrombin complex concentrate and recombinant factor VIIa have been suggested as effective treatment options during inhibitor-induced bleeding complications. Meanwhile, several specific reversal agents have been developed. In this review, an overview of the current state of nonspecific and specific reversal agents for the direct factor Xa inhibitors is provided, focusing on the biochemistry and mechanism of action and the preclinical assessment of newly emerging therapies.

The use of 4F-PCC to correct direct oral anticoagulant-induced coagulopathy: An observational analysis

BACKGROUND

With the approval of four-factor prothrombin complex concentrate (4F-PCC, Kcentra) for the reversal of vitamin K antagonist-associated bleeding in the United States, it has become a relatively common practice for 4F-PCC to be used in an "off-label" fashion to correct coagulopathy caused by direct oral anticoagulants (DOACs). However, the efficacy and safety of 4F-PCC have not been well studied in this scenario.

MATERIALS AND METHODS

We performed a retrospective observational study on the off-label use of 4F-PCC for reversing bleeding associated with DOACs in a level 1 trauma centre between November 2014 and February 2017. International normalised ratio (INR) and Hgb prior to and post 4F-PCC infusion, clinical outcome and thromboembolic events within 24 hours and 45 days of 4F-PCC administration were collected.

RESULTS

We identified 24 patients on DOACs who received 4F-PCC for severe haemorrhage and emergent surgeries. Most patients showed improved haemorrhage as demonstrated by stabilised intracranial haemorrhage sizes and/or by steady Hgb levels. No thromboembolic event was identified within 24 hours of 4F-PCC administration. However, 16.7% patients (4/24) experienced thromboembolic events 2 to 45 days after receiving 4F-PCC.

CONCLUSION

Our data showed that 4F-PCC was relatively efficient in correcting DOAC-induced coagulopathy. We did notice that 16.7% of patients experienced some form of thromboembolic events in the days-to-weeks after 4F-PCC administration, although the imputability of 4F-PCC in these processes (vs their underlying disease) is difficult to determine. Additional prospective studies would be warranted to further evaluate the safety of 4F-PCC for this off-label indication.

Four-factor prothrombin complex concentrate for life-threatening bleeds or emergent surgery: A retrospective evaluation

PURPOSE

Previous trials investigating usage of four-factor prothrombin complex concentrate (4F-PCC) excluded patients with various thrombotic risk factors. The objective of this study was to evaluate the safety and effectiveness of 4F-PCC in a real-world setting based on an institutional protocol that does not have strict exclusion criteria.

METHODS

This was a retrospective study of adult patients who received 4F-PCC. The primary outcome was a confirmed thromboembolism within 14 days after 4F-PCC administration. Secondary outcomes included international normalized ratio (INR) correction to <1.5 at first draw and incidence of INR rebound for patients undergoing reversal of warfarin and hemostatic effectiveness for patients experiencing a bleed.

RESULTS

Ninety-three patients received 4F-PCC. Sixty-three (67.7%) were reversed for bleeding and 30 (32.3%) for surgery. Eleven patients (11.8%) developed a thromboembolism within 14 days. The median (interquartile range) time to event was 5 (2-7) days. Significant risk factors were heparin-induced thrombocytopenia (P= .01) and major surgery within 14 days (P= .02), as well as the presence of >6 thrombotic risk factors (P= .01). For patients post-warfarin reversal, 45/63 (71.4%) achieved INR correction at first draw, 55/63 (87.3%) achieved INR correction within 24 hours, and 14/55 (25.5%) experienced INR rebound. Of these 14 patients, 8 (57.1%) did not receive concomitant vitamin K.

CONCLUSIONS

4F-PCC was associated with a notable thromboembolic risk. All patient-specific risk factors should be considered prior to administration. 4F-PCC remains a useful agent for warfarin reversal. Lack of concomitant vitamin K may contribute to INR rebound.

Fibrin matrices: The versatile therapeutic delivery systems

Fibrin sealants, that have been employed for over a century by surgeons to stop post surgery bleeding, are finding novel applications in the controlled delivery of antibiotics and several other therapeutics. Fibrinogen can be easily purified from blood plasma and converted by thrombolysis to fibrin that undergoes spontaneous aggregation to form insoluble clot. During the gelling, fibrin can be formulated into films, clots, threads, microbeads, nanoconstructs and nanoparticles. Whole plasma clots in the form of beads and microparticles can also be prepared by activating endogenous thrombin, for possible drug delivery. Fibrin formulations offer remarkable scope for controlling the porosity as well as in vivo degradability and hence the release of the associated therapeutics. Binding/covalent-linking of therapeutics to the fibrin matrix, crosslinking of the matrix with bifunctional reagents and coentrapment of protease inhibitors have been successful in regulating both in vitro and in vivo release of the therapeutics. The release rates can also be remarkably lowered by preentrapment of therapeutics in insoluble particles like liposomes or by anchoring them to the matrix via molecules that bind them as well as fibrin.