Smaller nadroparin dose reductions required for patients with renal impairment: A multicenter cohort study

BACKGROUND

Guidelines advise 50 % and 25 % dose reduction of the therapeutic nadroparin dose (86 IU/kg) in patients with eGFR 15-29 and 30-60 ml/min respectively. For monitoring, peak anti-Xa levels are suggested. Data lack whether this results in therapeutic anti-Xa levels or in anti-Xa levels that are comparable to those of patients without renal impairment.

AIMS

To determine dose ranges in patients with renal impairment that result in therapeutic anti-Xa levels and to determine the percentage of the 86 IU/kg dose that results in anti-Xa levels normally occurring in patients without renal impairment.

METHODS

A retrospective cohort study was conducted in five hospitals. Patients ≥18 years of age, with an eGFR ≥ 15 ml/min were included. The first correctly sampled peak (i.e. 3-5 h after ≥ third administration, regardless of dose per patient) was included. Simulated prediction models were developed using multiple linear regression.

RESULTS

770 patients were included. eGFR and hospital affected the association between dose and anti-Xa level. The doses for peak anti-Xa levels of 0.75 IU/ml differed substantially between hospitals and ranged from 55 to 91, 65-359 and 68-168 IU/kg in eGFR 15-29, 30-60 and > 60 ml/min/1.73m2, respectively. In eGFR 15-29 and 30-60 ml/min/1.73m2, doses of 75 % and 91 % of 86 IU/kg respectively, were needed for anti-Xa levels normally occurring in patients with eGFR > 60 ml/min.

CONCLUSION

We advise against anti-Xa based dose-adjustments as long as anti-Xa assays between laboratories are not harmonized and an anti-Xa target range is not validated. A better approach might be to target levels similar to eGFR > 60 ml/min/1.73m2, which are achieved by smaller dose reductions.

Therapeutically dosed low molecular weight heparins in renal impairment: a nationwide survey

PURPOSE

International guidelines vary in their recommendations whether or not to reduce the therapeutic dose of low molecular weight heparins (LMWHs) in renal impairment. The use of anti-Xa monitoring as a basis of dose adjustments is also a matter of debate. As this may lead to variations in treatment policies, we aimed to study the treatment policies of therapeutically dosed LMWHs in renal impairment in Dutch hospitals.

METHODS

An 11-item survey was distributed between June 2020 and March 2021 to hospital pharmacists, representing Dutch hospital organisations. Primary outcomes were the dosing regimens of therapeutically dosed LMWHs in renally impaired patients. Secondary outcomes were the proportion of hospitals that used anti-Xa monitoring and the anti-Xa target range used.

RESULTS

There was a response from 56 of 69 (81%) Dutch hospital organisations where in each case a hospital pharmacist completed the survey. In these hospitals, 77 LMWH regimens were in use. In 76 of 77 (99%) regimens, a regular dose reduction was used at the start of treatment. Fifty-five of these hospitals used a dose reduction if estimated glomerular filtration rate (eGFR) < 50 ml/min and 17 used a dose reduction if eGFR < 30 ml/min. Anti-Xa levels were not routinely monitored in 40% of regimens, while 22% monitored anti-Xa if eGFR < 50 ml/min, 27% if eGFR < 30 ml/min and 10% in other eGFR cutoff values. Target ranges of 1.0-2.0 IU/ml (once daily) and 0.5/0.6-1.0 IU/ml (twice daily) were used in 69% of regimens that included monitoring of anti-Xa.

CONCLUSION

Treatment policies show substantial diversity in therapeutically dosed LMWHs in renally impaired patients. The most commonly used treatment regimen was a regular dose reduction if eGFR is < 50 ml/min, without anti-Xa monitoring.

Management of combined oral antithrombotic therapy by an Antithrombotic Stewardship Program: a prospective study

AIMS

Antithrombotic management initiatives could prevent inappropriate prescribing and improve patient outcomes especially in patients on combined antithrombotic therapy. To investigate this, a multidisciplinary antithrombotic stewardship program (ASP) was implemented in our hospital. The primary aim of this study was to determine the efficacy of this ASP by assessing the number of patients on combined antithrombotic therapy for whom one or more interventions were needed.

METHODS

A prospective cohort study in a large teaching hospital was conducted. Hospitalized patients were included who received combined antithrombotic therapy in which an oral anticoagulant was combined with one (double therapy) or two (triple therapy) platelet aggregation inhibitors. The ASP proactively evaluated the appropriateness of this combined antithrombotic therapy. If needed, ASP improved the concerned therapy. Each improvement measurement recommended by the ASP was counted as one intervention.

RESULTS

A total of 460 patients were included over a period of 12 months. 251 (54.6%) patients required at least one intervention from the ASP. The most common interventions were: 1) to define and document the maximum duration of the combined antithrombotic therapy needed instead of lifetime use of the combination (65.5%), 2) to discontinue antithrombotic therapy as the proper indication was lacking (19.4%), and 3) to adjust the dosage (8.1%).

CONCLUSION

An intervention was needed in more than half of the patients on combined antithrombotic therapy. Implementation of an dedicated ASP evaluating combined antithrombotic therapy improves the use and safety of antithrombotic medication.

Fixed Versus Variable Dosing of Prothrombin Complex Concentrate for Bleeding Complications of Vitamin K Antagonists-The PROPER3 Randomized Clinical Trial

STUDY OBJECTIVE

To determine if a fixed dose of 1000 IU of 4-factor prothrombin complex concentrate (4F-PCC) is as effective as traditional variable dosing based on body weight and international normalized ratio (INR) for reversal of vitamin K antagonist (VKA) anticoagulation.

METHODS

In this open-label, multicenter, randomized clinical trial, patients with nonintracranial bleeds requiring VKA reversal with 4F-PCC were allocated to either a 1,000-IU fixed dose of 4F-PCC or the variable dose. The primary outcome was the proportion of patients with effective hemostasis according to the International Society of Thrombosis and Haemostasis definition. The design was noninferiority with a lower 95% confidence interval of no more than -6%. When estimating sample size, we assumed that fixed dosing would be 4% superior.

RESULTS

From October 2015 until January 2020, 199 of 310 intended patients were included before study termination due to decreasing enrollment rates. Of the 199 patients, 159 were allowed in the per-protocol analysis. Effective hemostasis was achieved in 87.3% (n=69 of 79) in fixed compared to 89.9% (n=71 of 79) in the variable dosing cohort (risk difference 2.5%, 95% confidence interval -13.3 to 7.9%, P=.27). Median door-to-needle times were 109 minutes (range 16 to 796) in fixed and 142 (17 to 1076) for the variable dose (P=.027). INR less than 2.0 at 60 minutes after 4F-PCC infusion was reached in 91.2% versus 91.7% (P=1.0).

CONCLUSION

The large majority of patients had good clinical outcome after 4F-PCC use; however, noninferiority of the fixed dose could not be demonstrated because the design assumed the fixed dose would be 4% superior. Door-to-needle time was shortened with the fixed dose, and INR reduction was similar in both dosing regimens.

A meta-analysis of andexanet alfa and prothrombin complex concentrate in the treatment of factor Xa inhibitor-related major bleeding

Background

Andexanet alfa (andexanet) and prothrombin complex concentrate (PCC) are both reversal agents for major bleeding in patients using factor Xa inhibitors (FXaIs). Our aim was to evaluate the current evidence for the effectiveness and safety of andexanet and PCC in a systematic review and meta-analysis.

Objectives

Primary objective was hemostatic effectiveness. Secondary objectives were thromboembolic event rate and mortality.

Methods

A systematic review was performed in PubMed and Embase. Studies describing the effectiveness and/or safety of PCC or andexanet in patients with major bleeding using FXaIs were included. Meta-analysis was performed using a random-effects model.

Results

Seventeen PCC studies, 3 andexanet studies, and 1 study describing PCC and andexanet were included, comprising 1428 PCC-treated and 396 andexanet-treated patients. None of the included studies had control groups, hampering a pooled meta-analysis to compare the two reversal agents. Separate analyses for andexanet and PCC were performed. In subgroup analysis, the pooled proportion of patients with effective hemostasis in studies that used Annexa-4 criteria demonstrated a hemostatic effectiveness of 0.85 (95% confidence interval [CI], 0.80-0.90) in PCC and 0.82 (95% CI, 0.78-0.87) in andexanet studies. The pooled proportion of patients with thromboembolic events was 0.03 (95% CI, 0.02-0.04) in PCC and 0.11 (95% CI, 0.04-0.18) in andexanet studies.

Conclusion

Based on the available evidence with low certainty from observational studies, PCC and andexanet demonstrated a similar, effective hemostasis in the treatment of major bleeding in patients using FXaIs. Compared to PCC, the thromboembolic event rate appeared higher in andexanet-treated patients.

Method agreement analysis and interobserver reliability of the ISTH proposed definitions for effective hemostasis in management of major bleeding

Essentials In 2016 the SSC proposed definitions for effective hemostasis in management of major bleeding. To validate these definitions, we studied the use in three large anticoagulant-reversal studies. Method agreement analysis and interobserver reliability showed at least acceptable agreement. Recommendations were made, advising use of the definition in hemostatic effectiveness studies. SUMMARY: Introduction In 2016 the Scientific and Standardization Subcommittee (SSC) on Control of Anticoagulation of the International Society on Thrombosis and Haemostasis (ISTH) proposed criteria to evaluate the effectiveness of anticoagulant reversal in major bleeding management. Testing and validation of these criteria are required. Objective To investigate the method agreement, interobserver reliability and applicability of the ISTH proposed definitions for hemostatic effectiveness. Methods Patient data from three anticoagulant-antidote studies were used for hemostatic effectiveness assessment using the ISTH-proposed definitions and clinical opinion. For every patient a case document was produced. For each cohort, four adjudicators were asked to assess the hemostatic effectiveness independently on a case-by-case basis. Agreement between the two methods of hemostatic effectiveness assessment was calculated using Cohen's kappa (κ), with a calculated sample size of at least 73 cases. Results The full dataset consisted of 116 cases, resulting in 464 assessments. Method agreement in outcome was observed in 364 of 464 assessments (78.5%), resulting in κ of 0.634 (95% CI: 0.575-0.694), or "substantial agreement." Interobserver reliability analysis of the proposed definitions computed an overall agreement of 54.2% with κ of 0.312 ("fair agreement"). Discussion Method agreement analysis shows that the conclusions drawn using the ISTH definitions have "substantial agreement" with clinical opinion. Interobserver reliability analysis demonstrated acceptable agreement. In-depth analysis provided minor opportunities for further improvement and correct application of the definition. The definition is recommended to be used in all future studies evaluating hemostatic effectiveness, taking the suggested recommendations into account.

Randomised controlled trial protocol to evaluate a fixed dose prothrombin complex concentrate against the variable dose in vitamin K antagonist related bleeding (PROPER3)

INTRODUCTION

There is currently little evidence for the optimal dosing strategy of four-factor prothrombin complex concentrates (PCC) in vitamin K antagonist (VKA)-related bleeds. The generally accepted dosing strategy is the use of a variable dose calculated using patient-specific characteristics as per manufacturer's instruction. However, evidence exists that the use of a fixed low dose of 1000 international units of factor IX (IU fIX) might also suffice. Recent studies indicate that in terms of haemostatic effectiveness, the fixed dosing strategy might be even superior to the variable dosing strategy. The PROPER3 (PROthrombin complex concentrate: Prospective Evaluation and Rationalisation, number 3) study aims to confirm the non-inferiority, and explore superiority, in haemostatic effectiveness of the fixed PCC dosing strategy compared with the variable dosing strategy in VKA-related extracranial bleeding emergencies.

METHODS AND ANALYSIS

The study is designed as a randomised controlled multicentre non-inferiority trial. Eligibility criteria are an indication for PCC due to VKA-related extracranial bleeding in subjects 18 years of age or older. The control group will receive a variable dose, determined by patient-specific bodyweight and international normalised ratio. The intervention group is dosed a fixed 1000 IU fIX PCC. Primary outcome is the haemostatic effectiveness of both treatments, as defined by the 2016 International Society on Thrombosis and Haemostasis (ISTH) criteria. The sample size is set at 155 patients per treatment arm, requiring 310 patients in total. Non-inferiority on the proportion (risk) difference of the primary outcome will be evaluated using the asymptotic Wald test for non-inferiority. The non-inferiority margin is set at 6%. The primary analysis will be based on the per-protocol population.

ETHICS AND DISSEMINATION

Study results will be published in an international journal, communicated to discipline-specific associations and presented at (inter)national meetings and congresses.

TRIAL REGISTRATION NUMBER

EUCTR2014-000392-33; Pre-results.

Fixed Versus Variable Dosing of Prothrombin Complex Concentrate in Vitamin K Antagonist-Related Intracranial Hemorrhage: A Retrospective Analysis

BACKGROUND

Millions of patients receive vitamin K antagonist (VKA) therapy worldwide. Annually 0.2-1 % of all VKA users develops an intracranial hemorrhage (ICH). Prothrombin complex concentrate (PCC) is administered to restore the INR ≤ 1.5 in an attempt to limit hematoma growth. In order to facilitate PCC dosing, our hospital recently changed from a variable dose based on bodyweight, baseline- and target-INR, to a fixed 1000 IU fIX PCC dosing protocol for ICH.

METHODS

In a before and after design, we compared successful achievement of an INR ≤ 1.5 with a fixed dosing strategy versus the variable dosing strategy of PCC in patients presenting with intracranial bleeding complications of VKA. Data of the two cohorts of patients were retrospectively collected from medical records.

RESULTS

A median dosage of 1750 IU was given per patient in the variable dose group (n = 25) versus 1000 IU in the fixed dose group (n = 28). In the intention-to-treat analysis, 96 % achieved an INR ≤ 1.5 after an initial dose in the variable dose cohort compared to 68 % in the fixed dose cohort (p = 0.01). An additional dose was given in 2 (8 %) versus 9 (32 %) patients, respectively (p = 0.04). The median door-to-PCC-order time was 42 versus 32 min (p = 0.37) and the door-to-needle time was 81, respectively 60 min (p = 0.42).

CONCLUSION

The fixed dose protocol necessitates additional PCC infusions more frequently to achieve a target INR ≤ 1.5. Door-to-order and door-to-needle time were shorter but, in this small cohort, not significantly so. The effect on clinical outcome remains unknown.

Long-term quality of VKA treatment and clinical outcome after extreme overanticoagulation in 14,777 AF and VTE patients

Vitamin K antagonists (VKA) are widely used in atrial fibrillation and venous thromboembolism (VTE). Their efficacy and safety depend on individual time in the therapeutic range (iTTR). Due to the variable dose-response relationship within patients, also patients with initially stable VKA treatment may develop extreme overanticoagulation (EO). EO is associated with an immediate bleeding risk, but it is unknown whether VKA treatment will subsequently restabilise. We evaluated long-term quality of VKA treatment and clinical outcome after EO. EO was defined as international normalized ratio (INR) ≥ 8.0 and/or unscheduled vitamin K supplementation. We included a consecutive cohort of initially stable atrial fibrillation and venous thromboembolism patients. In EO patients, the 90 days pre- and post-period were compared. In addition, patients with EO were compared with patients without EO using a matched 1:2 cohort. Of 14,777 initially stable patients, 800 patients developed EO. The pre-period was characterised by frequent overanticoagulation, and half of EO patients had an inadequate iTTR (< 65 %). After EO, underanticoagulation became more prevalent. Although the mean time between INR-measurements decreased from 18.6 to 13.2 days, after EO inadequate iTTR became more frequent (62 %), p-value < 0.001. A 2.3 times (95 % confidence interval [CI] 2.0-2.5) higher risk for iTTR< 65 % after EO, was accompanied by increased risk of bleeding (hazard ratio [HR] 2.1;CI 1.4-3.2), VKA-related death 17.0 (HR 17.0;CI 2.1-138) and thrombosis (HR 5.7;CI 1.5-22.2), compared to the 1600 controls. In conclusion, patients continuing VKA after EO have long-lasting inferior quality of VKA treatment despite intensified INR-monitoring, and an increased risk of bleeding, thrombosis and VKA-related death.

An observational, prospective, two-cohort comparison of a fixed versus variable dosing strategy of prothrombin complex concentrate to counteract vitamin K antagonists in 240 bleeding emergencies

BACKGROUND

Despite years of experience with vitamin K antagonist-associated bleeding events, there is still no evidence to help identify the optimal treatment with prothrombin complex concentrates. Variable dosing and fixed dose strategies are being used. In this observational prospective two-cohort study, we aimed to assess the non-inferiority of a low fixed PCC dose (1,040 IU Factor IX) compared to the registered variable dosing regimen based on baseline International Normalized Rate, bodyweight, and target International Normalized Rate, to counteract vitamin K antagonists in a bleeding emergency in a daily clinical practice setting.

DESIGN AND METHODS

Non-inferiority of the fixed prothrombin complex concentrate dose was hypothesized with a margin of 4%. Main end points were proportion of patients reaching the target International Normalized Rate (< 2.0) after prothrombin complex concentrate treatment, and successful clinical outcome.

RESULTS

Target International Normalized Rate was reached in 92% of the fixed dose patients (n=101) versus 95% of variable dose patients (n=139) resulting in a risk difference of -2.99% (90% CI: - 8.6 to 2.7) (non-inferiority not confirmed). Clinical outcome was successful in 96% and 88% of fixed versus variable dose, respectively, with a risk difference of 8.3% (90% CI: 2.7-13.9; non-inferiority confirmed).

CONCLUSIONS

Although a lower fixed prothrombin complex concentrate dose was associated with successful clinical outcome, fewer patients reached the target International Normalized Rate.

Fixed versus variable dose of prothrombin complex concentrate for counteracting vitamin K antagonist therapy

BACKGROUND

Although prothrombin complex concentrate (PCC) is often used to counteract vitamin K antagonist (VKA) therapy, evidence regarding the optimal dose for this indication is lacking. In Dutch hospitals, either a variable dose, based on body weight, target INR (international normalised ratio) and initial INR, or a fixed dose is used.

AIM/OBJECTIVES

In this observational, pilot study, the efficacy and feasibility of the fixed dose strategy compared to the variable dosing regimen, is investigated.

MATERIALS AND METHODS

Consecutive patients receiving PCC (Cofact®, Sanquin, Amsterdam) for VKA reversal because of a major non-cranial bleed or an invasive procedure were enrolled in two cohorts. Data were collected prospectively in the fixed dose group, cohort 1, and retrospectively in the variable dose regimen, cohort 2. Study endpoints were proportion of patients reaching target INR and successful clinical outcome.

RESULTS

Cohort 1 consisted of 35 and cohort 2 of 32 patients. Target INR was reached in 70% of patients in cohort 1 versus 81% in cohort 2 (P = 0·37). Successful clinical outcome was seen in 91% of patients in cohort 1 versus 94% in cohort 2 (P = 1·00). Median INR decreased from 4·7 to 1·8 with a median dosage of 1040 IU factor IX (F IX) in cohort 1 and from 4·7 to 1·6 with a median dosage of 1580 IU F IX in cohort 2.

CONCLUSION

This study suggests that a fixed dose of 1040 IU of F IX may be an effective way to rapidly counteract VKA therapy in our patient population and provides a basis for future research.

In vitro performance of two common valved holding chambers with a chlorofluorocarbon-free beclomethasone metered-dose inhaler

STUDY OBJECTIVE

To compare in vitro aerosol deposition from a beclomethasone dipropionate metered-dose inhaler (MDI) containing hydrofluoroalkane propellant with that of the MDI in combination with two common valved holding chambers (VHCs) to evaluate how these VHCs affect the respirable dose of beclomethasone dipropionate.

DESIGN

In vitro aerosol deposition study.

SETTING

University research center.

DEVICES

Beclomethasone dipropionate hydrofluoroalkane MDI alone, the MDI with OptiChamber VHC, and the MDI with AeroChamber-Plus VHC.

INTERVENTION

The respirable dose (1-5-microm aerosol particles) of beclomethasone dipropionate was determined by sampling 10 80-microg actuations from five runs with each configuration (MDI alone, MDI with OptiChamber, and MDI with AeroChamber-Plus), using a well-established in vitro cascade impactor method.

MEASUREMENTS AND MAIN RESULTS

Beclomethasone dipropionate aerosol was washed from the impactor with 50% methanol and quantified by means of high-performance liquid chromatography. Differences among outcomes were determined by using analysis of variance. Mean beclomethasone dipropionate respirable dose from AeroChamber-Plus (27.2 +/- 10.0 microg/actuation) was not significantly different (p>0.05) from that of the MDI alone (29.0 +/- 7.0 microg/actuation). OptiChamber respirable dose (12.8 +/- 6.0 microg/actuation) was less than half that produced by either the AeroChamber-Plus or the MDI alone (p=0.013).

CONCLUSIONS

The OptiChamber and AeroChamber-Plus VHCs do not demonstrate equivalent in vitro performance when used with a beclomethasone dipropionate MDI that contains hydrofluoroalkane propellant. The respirable dose of beclomethasone dipropionate aerosol from the hydrofluoroalkane MDI was decreased by only 6% when the MDI was mated to an AeroChamber-Plus VHC and by 56% when used with an OptiChamber VHC.