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

IntroductionFour-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.MethodsRetrospective, 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.ResultsAfter 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).ConclusionA 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.     

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

PurposePrevious 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.MethodsThis 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.ResultsNinety-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.Conclusions4F-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.     

Multi-centered evaluation of a novel fixed-dose four-factor prothrombin complex concentrate protocol for warfarin reversal

IntroductionPrevious studies have shown fixed-dose 4PCC to be as effective as standard-dose 4PCC for warfarin reversal. However, certain patient populations such as those with high total body weight (TBW) or elevated baseline INR may be at increased risk for treatment failure. The purpose of this study was to validate the efficacy of a novel fixed-dose 4PCC protocol for warfarin reversal.MethodsThis was a multi-centered observational comparison of patients who received 4PCC for warfarin reversal. Fixed-dose patients received 1500 units of 4PCC with the dose increased to 2000 units in patients with a baseline INR ≥ 7.5, a TBW ≥ 100 kg, or for intracranial hemorrhage (ICH). Standard-dosing followed manufacturer recommendations. The primary outcome was achievement of a post-4PCC INR of ≤1.4. Secondary outcomes included target INR achievement among patients with a baseline INR ≥ 7.5, a TBW ≥ 100 kg, or neurologic bleeding indications; hospital length of stay; cost of therapy; and thromboembolic complications.ResultsA total of 116 patients were included in the standard-dose group and 75 in the fixed-dose group. There was no difference in the primary outcome (65% vs 57%, p = 0.32). There was no difference in secondary outcomes aside from cost of therapy in which fixed-dose 4PCC was less expensive than standard-dose 4PCC.ConclusionA fixed-dose 4PCC regimen for warfarin reversal of 1500 units, with an increased dose of 2000 units for select patients, is as effective as standard-dose 4PCC for INR reversal.     

Four-factor prothrombin complex concentrate dose response relationship with INR for warfarin reversal

IntroductionFor reversal of warfarin-induced coagulopathy, FDA labeling of four-factor prothrombin complex concentrate (4F-PCC) endorses a dosing strategy based on body weight and baseline INR. Recent literature suggests lower, fixed doses of 4F-PCC may be equally efficacious. The present evaluation aims to characterize the relationship between 4F-PCC dose and degree of reduction in INR.MethodsThis is a retrospective, single-center review of 4F-PCC administrations for warfarin reversal between May 2014 and August 2017. The primary endpoint evaluates the relationship between doses of 4F-PCC and INR measurement after reversal, represented as a linear regression. Exploratory endpoints characterize the relationships of both body weight and baseline INR, the components determining initial 4F-PCC dose, with INR after reversal. Additionally, for records presenting with an INR of 2–3.9, mean INR after reversal was characterized as a function of two 4F-PCC dose cohorts (< 30 and ≥30 IU fIX/kg).ResultsA significant linear relationship between 4F-PCC dose and INR after reversal (INR after 4F-PCC = 1.3651–0.00004(4F-PCC Dose), p = 0.0071, R² = 0.0630) was observed. Body weight and baseline INR were not correlated with INR after reversal. The subgroup analysis of records with presenting INR of 2–3.9 demonstrated no difference in mean INR after reversal with 4F-PCC for those receiving <30 IU fIX/kg and those receiving ≥30 IU fIX/kg.ConclusionThis evaluation found no clinically relevant relationship with 4F-PCC doses and degree of INR reversal. Further prospective study is required to determine optimal dosing schemes of 4F-PCC for warfarin reversal.     

Prospective Evaluation of a Fixed-Dose 4-Factor Prothrombin Complex Concentrate Protocol for Urgent Vitamin K Antagonist Reversal

BackgroundFour-factor prothrombin complex concentrate (4F-PCC) is the standard of care for reversal of vitamin K antagonists (VKAs). Research has demonstrated noninferior efficacy with the use of lower, fixed-dose strategies for 4F-PCC dosing.ObjectivesWe compared a fixed-dose 4F-PCC protocol to weight-based dosing at our institution.MethodsThis was a multicenter, noninferiority, interventional, quasiexperimental cohort study including subjects who were administered 4F-PCC for VKA reversal. The retrospective cohort consisted of subjects given a weight-based dose of 4F-PCC dependent on international normalized ratio (INR). The prospective cohort was managed with a fixed-dose protocol. The fixed dose was 1500 units of factor IX unless subjects weighed >100 kg or had a baseline INR >7.5, in which case the dose was 2000 units of factor IX. The primary endpoint was achievement of a postinfusion INR of <2. Secondary endpoints included achievement postinfusion INR <1.5, mean 24-h INR, 7-day mortality, and 7-day venous thromboembolic events.ResultsTwenty-four subjects were enrolled in the prospective cohort and 30 in the retrospective cohort. A postinfusion INR <2 was achieved in 96% of subjects in the retrospective cohort and 95% in the prospective cohort (p = 0.0035 for noninferiority). A postinfusion INR <1.5 occurred in 90% of subjects in the retrospective cohort and 75% in the prospective cohort (p > 0.4 for noninferiority). There were no significant differences in 24-h postinfusion INRs, mortality, or venous thromboembolic events.ConclusionThe use of a fixed-dose 4F-PCC protocol is safe and effective for the rapid reversal of VKA-associated anticoagulation.     

Is there a difference in efficacy,safety, and cost-effectiveness between 3-factor and 4-factor prothrombin complex concentrates among trauma patients on oral anticoagulants?

PurposeThe aim of this study was to compare the efficacy, safety, and cost-effectiveness of 3-factor prothrombin complex concentrate (3F-PCC) vs 4-factor prothrombin complex concentrate PCC (4F-PCC) in trauma patients requiring reversal of oral anticoagulants.Materials and methodsAll consecutive trauma patients with coagulopathy (international normalized ratio [INR] ≥ 1.5) secondary to oral anticoagulants who received either 3F-PCC or 4F-PCC from 2010 to 2014 at 2 trauma centers were reviewed. Efficacy was determined by assessing the first INR post–PCC administration, and successful reversal was defined as INR less than 1.5. Safety was assessed by reviewing thromboembolic events, and cost-effectiveness was calculated using total treatment costs (drug acquisition plus transfusion costs) per successful reversal.ResultsForty-six patients received 3F-PCC, and 18 received 4F-PCC. Baseline INR was similar for 3F-PCC and 4F-PCC patients (3.1 ± 2.3 vs 3.4 ± 3.7, P = .520). The initial PCC dose was 29 ± 9 U/kg for 3F-PCC and 26 ± 6 U/kg for 4F-PCC (P = .102). The follow-up INR was 1.6 ± 0.6 for 3F-PCC and 1.3 ± 0.2 for 4F-PCC (P = .001). Successful reversal rates in patients were 83% for 4F-PCC and 50% for 3F-PCC (P = .022). Thromboembolic events were observed in 15% of patients with 3F-PCC vs 0% with 4F-PCC (P = .177). Cost-effectiveness favored 4F-PCC ($5382 vs $3797).ConclusionsThree-factor PCC and 4F-PCC were both safe in correcting INR, but 4F-PCC was more effective, leading to better cost-effectiveness. Replacing 3F-PCC with 4F-PCC for urgent coagulopathy reversal may benefit patients and institutions.     

Four-factor prothrombin complex concentrate for the reversal of factor Xa inhibitors for traumatic intracranial hemorrhage

ObjectiveThe objective of this study was to determine the effectiveness and safety of four-factor prothrombin complex concentrate (4F-PCC) for the reversal of factor Xa inhibitors in patients with traumatic intracranial hemorrhage (ICH).MethodsThis was a retrospective cohort study of patients taking factor Xa inhibitors with traumatic ICH between March 1, 2015 and August 31, 2017 at two trauma centers. The primary outcome was in-hospital mortality in patients who received 4F-PCC (4F-PCC group) compared to those who did not (no reversal group). Secondary outcomes included functional recovery, hospital and intensive care unit (ICU) length of stay (LOS), and thromboembolic complications.ResultsThere were 62 patients included in the study. Injury Severity Score (ISS) was significantly higher in the 4F-PCC group (17.6 vs. 12.1, p = 0.019). The 4F-PCC group had a significantly higher mortality (22.9% vs. 3.7%, p = 0.034) and longer ICU LOS (2.5 vs. 1.4 days, p = 0.0024). The no reversal group had a significantly higher incidence of ischemic stroke/transient ischemic attack (TIA) (0% vs. 14.8%, p = 0.019). After controlling for ISS, there was no significant difference in mortality (p = 0.20), ICU LOS (p = 0.64), or ischemic stroke/TIA (p = 0.94). There was no difference in hospital LOS, discharge disposition, final Activity Measure for Post Acute Care daily activity score, VTE, or MI.ConclusionPatients with a higher ISS received 4F-PCC preferentially, which led to an apparent mortality benefit the no reversal group. After adjusting for baseline differences between groups, there was no difference in mortality, functional recovery, hospital and ICU LOS, or thromboembolic complications.     

Evaluation of Fixed-Dose Four-Factor Prothrombin Complex Concentrate for Emergent Warfarin Reversal in Patients with Intracranial Hemorrhage

Background

Different strategies exist for dosing four-factor prothrombin complex concentrate (PCC4) for international normalized ratio (INR) reversal in the setting of life-threatening bleeding. Fixed doses ranging from 1000 IU to 1750 IU have demonstrated efficacy similar to weight-based dosing, however, few studies look exclusively at intracranial hemorrhage (ICH).

Modified version of the American College of Cardiology's recommendation for low-dose prothrombin complex concentrate is effective for warfarin reversal

BackgroundDosing of four factor prothrombin complex concentrate (4PCC) for warfarin reversal remains controversial. Recently, the American College of Cardiology (ACC) recommended a low-dose PCC regimen as an option for warfarin reversal in acute major bleeding. We performed a retrospective study evaluating if a modified version of the ACC guideline recommendations was effective for warfarin reversal in acute major bleeds when compared to traditional variable dosing.MethodsThis was a retrospective cohort study of patients who received 4PCC for warfarin reversal in a 12 month period. We included patients that were ≥18 years of age, received 4PCC for warfarin reversal, and had an initial International Normalized Ratio (INR) of >2. Our primary outcome was the number of patients who had a post-4PCC infusion INR of <1.6.ResultsA total of 60 patients were included in the final analysis with 30 patients stratified to the traditional dosing and low-dose groups, respectively. Patient demographics were similar between both groups. We found no difference in the number of patients who had a post-4PCC infusion INR <1.6 between the traditional dosing and low dosing group (90.0% vs. 86.7%; p = 0.68). Additionally, we found no difference between post-infusion median INRs in each group (1.35 vs. 1.30; p = 0.16). Approximately 1000 units per patient were spared when utilizing the low-dose regimen.ConclusionA modified version of the ACC's low-dose 4PCC option for warfarin reversal achieves similar outcomes for lowering INR values compared to traditional variable dosing regimens.     

Thromboelastometry-guided anticoagulation reversal in a patient with ventricular assist device with intracranial hemorrhage

Intracranial hemorrhage (ICH) is a known complication in patients with ventricular assist devices (VAD). We present a case of a 42-year-old male with a VAD and on warfarin who presented to the emergency department with ICH necessitating anticoagulant reversal. An attenuated dose of 15 units/kg of 4-factor prothrombin complex-concentrates (4F-PCC) was given and the patient’s coagulation profile was subsequently assessed using rotational thromboelastometry (ROTEM®) to determine appropriateness of reversal. ROTEM® analysis showed adequate reversal at the time of assessment and the patient ultimately returned home without further functional deficits, highlighting the role of ROTEM® to guide anticoagulation reversal in the VAD patient population.     

Emergent reversal of oral factor Xa inhibitors with four-factor prothrombin complex concentrate

BackgroundControversy exists regarding first-line use of the recently approved reversal agent andexanet alfa due to limitations of the ANEXXA-4 study, thrombotic risks, and high medication acquisition cost. The purpose of this study was to evaluate the safety and effectiveness of 4F-PCC for the reversal of emergent oral fXa inhibitor-related bleeding. Furthermore, we aimed to evaluate a subgroup using strict ANNEXA-4 patient selection criteria.MethodsThis was a retrospective study conducted utilizing chart review of adult patients that received 4F-PCC for oral fXa inhibitor-related bleeding. The primary endpoint was the rate of clinical success defined as achieving excellent or good hemostatic effectiveness following the administration of 4F-PCC. Secondary endpoints included in-hospital mortality and arterial/venous thromboembolism, and cost compared with andexanet alfa.ResultsA total of 119 patients were included, with 83 patients in the ANNEXA-4 criteria subgroup. Eighty-five of the 119 patients (71%) required reversal due to intracranial bleeding. Prior to reversal, 70 patients (59%) were taking apixaban and 49 patients (41%) were taking rivaroxaban. Clinical success was achieved in 106 of 119 patients (89%) and 74 of 83 patients (90%) in the strict criteria subgroup. Three of 119 patients (2.5%) had a thrombotic event during hospital stay and the overall mortality rate was 13%. The average cost increase of andexanet alfa compared to 4F-PCC would have been $29,500 per patient.ConclusionsAdministration of 4F-PCC for the reversal of oral fXa inhibitors was effective with relatively low thrombotic risk. Further direct prospective comparison of 4F-PCC to andexanet alfa is warranted.     

Evaluation of fixed versus variable dosing of 4-factor prothrombin complex concentrate for emergent warfarin reversal

Study objectiveThis study compares the safety and efficacy of a fixed dose of 4-factor prothrombin complex concentrate (4FPCC) to the FDA-approved variable dosing for reversal of warfarin-induced anticoagulation.MethodsThis was a single-center, prospective, open-label, randomized controlled trial with subjects randomized to 4FPCC at a fixed dose of 1500 IU or the FDA-approved variable dosing regimen. The primary efficacy outcome (reversal success) was defined as a post-intervention international normalized ratio (INR) of less than or equal to 1.5. Given that 4FPCC is the standard of care for reversal of warfarin-induced anticoagulation an active-controlled approach was employed with the two dosing regimens compared based on efficacy, cost, and safety outcomes.Results71 subjects (34 in the fixed dose group and 37 in the variable dose group) completed the study. There were no significant differences in age, gender, weight, initial INR, or indication for 4FPCC administration between the two treatment groups. Reversal success in the fixed-dose group was 61.8%, while in the variable dose group reversal success was 89.2%. Reversal success in the fixed-dose group was significantly lower than the rate of reversal success in the variable dose group (27.4% lower, p = 0.011).ConclusionThe results of this study provide evidence that fixed dosing results in lower reversal success rates as compared to variable dosing of 4FPCC for warfarin-induced anticoagulation.     

Prothrombin complex concentrate for the urgent reversal of warfarin. Assessment of a standard dosing protocol

BackgroundOctaplex®, a six factor prothrombin complex concentrate (PCC), has recently been approved for use in Canada. The optimal dose of Octaplex has yet to be established and our study was designed to monitor the efficacy of a low standard dose.Study design and methodsPatients on warfarin treatment in need of urgent reversal for bleeding, invasive procedures or surgery were given a standard dose of 40 ml (1000 IU FIX, 14 IU/kg). We conducted a retrospective chart review of 231 patients.ResultsPatients given concurrent frozen plasma (FP) for reversal were eliminated from the study. Overall, 150 patients were reviewed and divided into three groups: (1) non-CNS bleeders, (2) CNS bleeders, and (3) non-bleeders. Correction of INR to 1.5 or less was achieved to the same extent in each group. Patients with active bleeding had the least successful bleeding cessation and patients with intracranial bleeding had the most dismal outcome compared to non-intracranial bleeders.ConclusionsOur data suggests that Octaplex, when given as a low standard dose is effective at INR reversal with 76% of our patients correcting to an INR of 1.5 or less. It appears that this dose is sufficient for non-bleeding patients. Bleeding patients may benefit most from a dose increase to achieve more complete reversal and patients with intracranial bleeding should achieve more complete reversal within 2 h of presentation.     

Fresh Frozen Plasma Dosing for Warfarin Reversal: A Practical Formula

ObjectiveTo provide a practical formula for fresh frozen plasma (FFP) dosing for warfarin reversal.Patients and MethodsWe reviewed data on all adult patients who received a total of 7778 units of FFP for warfarin reversal at Sentara Norfolk General Hospital (Norfolk, VA) between April 1, 2009, and March 31, 2010. Patients with advanced liver disease, consumptive or dilutional coagulopathy, and administration of activated factor VII or prothrombin complex concentrate were excluded. First, we used regression analysis on the FFP1 subset (patients whose international normalized ratio [INR] was checked before and after 1 FFP administration) and derived a simple formula: DeltaINR (PreINR – PostINR) after 1 FFP = a × PreINR + b, where PreINR and PostINR are the INR values before and after FFP administration, respectively, and a and b are constants. In the validation step, the formula obtained for the FFP1 subset was repeatedly applied to the FFP2 (patients who received 2 units of FFP back-to-back without an intervening INR check), FFP3, and FFP4 subsets.ResultsA total of 956 patients were included. The formula DeltaINR after 1 FFP = 0.57 × PreINR – 0.72 explained 82.6% of the total variance in INR change in the FFP1 subset (n=308; P<.01). Including age, sex, weight, FFP-to-PostINR interval, or administration of vitamin K marginally improved the model. Repeated application of the FFP1 formula to the FFP2 to 4 subsets combined confirmed the accuracy of the FFP1 formula across the entire data set (n=643; R²=95% between predicted and actual DeltaINR; P<.01).ConclusionThis formula provides a practical and accurate method for FFP dosing for warfarin reversal.     

Experiences with an activated 4-factor prothrombin complex concentrate (FEIBA) for reversal of warfarin-related bleeding

Background

Current reversal options for warfarin-related bleeding are limited but include fresh frozen plasma, recombinant factor VIIa, or a prothrombin complex concentrate (PCC). There are little data discussing the use of activated 4-factor PCC for warfarin reversal.

Objectives

This review will summarize our experiences with FEIBA (Baxter, Deerfield, IL), an activated 4-factor PCC, for the reversal of warfarin-related bleeding in a community hospital.

Methods

A protocol was put in place in March of 2011, which outlined the use of FEIBA for the emergent reversal of warfarin-related coagulopathy. A low fixed dose was given based on international normalized ratio (INR). For an INR less than 5.0, 500 U of FEIBA was administered. For an INR greater than or equal to 5.0, 1000 U of FEIBA was given. Intravenous vitamin K was given concurrently regardless of INR.

Results

Sixteen patients were treated with FEIBA per the protocol. Average patient age was 73 years. Intracranial hemorrhage was the most common indication for reversal. Mean pre-treatment INR was 3.56 (1.3-6.8); mean post-treatment INR was 1.16 (1.01-1.32). Two of the patients required a second 500-U dose, per the protocol, for an INR that had not yet normalized. Bleeding appeared clinically controlled in 93% of cases. Eighty-seven percent of patients survived to discharge. There were no signs or symptoms of thrombosis in any of the cases.

Conclusions

Emergent reversal of warfarin utilizing a fixed, low dose of FEIBA appears to be efficacious, consistent, and safe. Further comparator studies with other reversal agents are needed.     

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

IntroductionCoagulopathy 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).MethodsIn 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.ResultsIn 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.ConclusionA 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.     

Activated prothrombin complex concentrate factor VIII inhibitor bypassing activity (FEIBA) for the reversal of warfarin-induced coagulopathy

Aims

The purpose of this study was to evaluate the effectiveness of a new, fixed, yet individualized dosing regimen of activated prothrombin complex concentrate factor VIII inhibitor bypassing activity (FEIBA) for warfarin reversal in the setting of a life-threatening bleeding in a secondary care center.

Methods

In this report we present a retrospective chart review of 72 patients who received FEIBA and 69 patients who received fresh-frozen plasma (FFP) to reverse the effects of warfarin in a setting of a life-threatening bleeding. In the FEIBA cohort, patients received 500 units of FEIBA when the initial INR was <5 or 1,000 units of FEIBA when initial INR was ≥5.

Results

FEIBA administration resulted in lower subsequent INR when compared with FFP and shorter time elapsed from drug administration to an INR ≤1.4 when compared with FFP. No significant differences in survival or in the length of hospital stay were observed. A higher FEIBA dose induced a bigger decrease in INR than the lower dose. We observed five adverse events (7%) that could potentially be related to FEIBA administration.

Conclusions

The presented dosing regimen results in safe reversal of warfarin-induced coagulopathy, which appears to be faster and more profound than following FFP. Moreover, the use of activated PCC (FEIBA) does not appear to carry an increased risk of thrombotic events when compared to the rate reported for several non-activated PCC preparations.     

Real-world utilization of andexanet alfa

ObjectiveIn 2018, the FDA approved andexanet alfa for the reversal of life-threatening hemorrhages in patients anticoagulated with apixaban or rivaroxaban. Yet, cost-effective factor Xa inhibitor reversal remains controversial. The objective of this study was to describe real world utilization of andexanet alfa.MethodsThis was a retrospective case series of patients receiving andexanet alfa between July 28, 2018 and April 29, 2019 at a large academic health system. Baseline demographics, anticoagulant type and reversal, as well as brain imaging were collected. Primary endpoints were stability of hematoma for intracranial hemorrhage (ICH), and hemostatic effectiveness for patients undergoing surgical procedures. Secondary endpoints were thromboembolism and 30 day mortality.ResultsOf the 25 patients evaluated, 13 received andexanet alfa for ICH. Eleven of the 13 had follow-up imaging available and stability was observed in 90.9%. Three patients received andexanet alfa for reversal prior to surgical procedures, and 100% hemostatic effectiveness was achieved. Nine patients received andexanet alfa for reversal of extracranial bleeding, including gastrointestinal bleed (n=4). There were no thrombotic events in our cohort, and 30 day mortality was 24%. Sixty-four percent of patients would have met exclusion criteria for the ANNEXA-4 trial.ConclusionThis is the largest series to date describing real-world utilization of andexanet alfa. Our series showed hemostatic efficacy in 90.9% of patients with ICH, and 100% in patients undergoing surgical procedures. There were no thrombotic complications. Yet, larger and comparative studies are needed to clarify the optimal agent and patient selection for reversal of factor Xa inhibitors.     

Low dose requirement for warfarin treatment in a patient with CYP2C9*3/*13 genotype

BackgroundCytochrome P450 2C9 (CYP2C9) is the major isoform of the CYP2C subfamily, and is involved in the metabolism of many clinically important therapeutic agents. Here we describe a patient who was intolerant of warfarin treatment because of impaired drug metabolism related to the CYP2C9*3/*13 genotype and high warfarin sensitivity associated with the VKORC1 1173TT genotype.CaseA 64-year-old Korean man had taken warfarin for treatment of an occluded left subclavian artery and atrial fibrillation. Although the warfarin doses prescribed were not high (14 mg/week) during the induction of anticoagulation, the prothrombin time (PT) was elevated to over 120 s after two weeks of warfarin therapy. For this patient, a very low dose of warfarin (4 mg/week) was required in order to achieve target INR values.ConclusionsTo the best of our knowledge, this is the first report of a patient with CYP2C9*3/*13 and VKORC1 1173TT genotypes who had slower than normal warfarin metabolism, resulting in the need to administer an extremely low dose of warfarin in order to achieve the target INR value. Our report reinforces the relevance of pharmacogenetic testing to explain warfarin dose variability and to enable individualized dosage adjustments for improved warfarin treatment outcomes.