Factor Xa Inhibitor-Related Intracranial Hemorrhage

Prothrombin complex concentrate in major bleeding associated with DOACs; an updated systematic review and meta-analysis

BACKGROUND

Four-factor prothrombin complex concentrate (PCC) is frequently used as a reversal agent for major bleeding in patients on factor Xa inhibitors. Piran et al. reviewed its safety and efficacy for the first time in 2018. However, more studies have been published on the matter since then. The aim of this study is to investigate the efficacy and safety of this use and update this review.

METHODS

We systematically searched in Medline, Scopus, and the Cochrane Library from 1/1/2018 to 6/19/2020. A random effects model meta-analysis of proportions was used to study the efficacy of PCC on major bleeding control, mortality and thrombosis incidence.

RESULTS

33 studies (n = 2568 patients), with the majority of studies being uncontrolled retrospective cohort studies, were included; atrial fibrillation was the main factor Xa inhibitors indication and approximately 62% of patients presented with intracranial hemorrhage. We estimated the pooled proportion outcomes for hemostasis (80%, CI 0.75-0.84), mortality (15%, CI 0.11-0.19) and thromboembolic adverse events (3%, CI 0.02-0.05). High versus low dose PCC did not affect hemostasis or thrombosis. Patients with ICH had higher mortality rates (22%, CI 0.13-0.32). Heterogeneity was significant (Ι² > 50% with p < 0.05) for all pooled proportional outcomes. The quality of evidence was low given that included studies were not randomized or controlled.

CONCLUSION

Our study demonstrates the efficacy and safety of the off label use of 4F PCC in major bleeding associated with factor Xa inhibitors. Our data require further validation with future randomized clinical trials.

Low-dose versus standard-dose four-factor prothrombin complex concentrate for factor-Xa inhibitor reversal in spontaneous and traumatic intracranial hemorrhage

STUDY OBJECTIVES

Current neurocritical care guidelines recommend 50 IU/kg four-factor prothrombin complex concentrate (4PCC) for factor Xa inhibitor (FXaI) reversal in intracranial hemorrhage (ICH) based on few clinical studies conducted among non-ICH subjects. Two recent studies suggest that low-dose (25 IU/kg) 4PCC may be similar to 50 IU/kg in reversal of FXaI in ICH, and both 25 and 50 IU/kg doses are used in clinical practice for this indication. To our knowledge, no studies have directly compared 25 IU/kg versus 50 IU/kg 4PCC for FXaI reversal in ICH. The purpose of this study is to determine whether there is a difference in hemostatic efficacy between 25 IU/kg versus 50 IU/kg 4PCC for FXaI reversal in ICH.

DESIGN

This multicenter, retrospective cohort study was performed in five hospitals in central Texas from November 2013 to December 2019.

DATA SOURCE

Patients were identified with a medication use report of 4PCC and were classified in the low- or standard-dose group based on whether the 25 IU/kg or 50 IU/kg dose was received, respectively.

PATIENTS

A total of 93 patients were included (25 IU/kg, n = 62; 50 IU/kg, n = 31).

MEASUREMENTS AND MAIN RESULTS

There was no difference in hemostatic efficacy between groups (82.3% low dose vs. 83.9% standard dose, p = 0.846). No differences were identified in-hospital mortality, length of stay, thrombotic events, or the need for surgery or additional blood products between groups.

CONCLUSION

For the reversal of FXaI in ICH, a 25 IU/kg dose may be an effective alternative to 50 IU/kg 4PCC dosing.

Andexanet Alfa or Prothrombin Complex Concentrate for Factor Xa Inhibitor Reversal in Acute Major Bleeding: A Systematic Review and Meta-Analysis

OBJECTIVES

To combine evidence on andexanet alfa and prothrombin complex concentrates for factor Xa inhibitor-associated bleeding to guide clinicians on reversal strategies.

DATA SOURCES

Embase, Pubmed, Web of Science, and the Cochrane Library.

STUDY SELECTION

Observational studies and randomized clinical trials studying hemostatic effectiveness of andexanet alfa or prothrombin complex concentrate for acute reversal of factor Xa inhibitor-associated hemorrhage.

DATA EXTRACTION

Two independent reviewers extracted the data from the studies. Visualization and comparison of hemostatic effectiveness using Sarode et al or International Society of Thrombosis and Hemostasis Scientific and Standardization Committee criteria at 12 and 24 hours, (venous) thrombotic event rates, and inhospital mortality were performed by constructing Forest plots. Exploratory analysis using a logistic mixed model analysis was performed to identify factors associated with effectiveness and venous thromboembolic event.

DATA SYNTHESIS

A total of 21 studies were included (andexanet: 438 patients; prothrombin complex concentrate: 1,278 patients). The (weighted) mean effectiveness for andexanet alfa was 82% at 12 hours and 71% at 24 hours. The (weighted) mean effectiveness for prothrombin complex concentrate was 88% at 12 hours and 76% at 24 hours. The mean 30-day symptomatic venous thromboembolic event rates were 5.0% for andexanet alfa and 1.9% for prothrombin complex concentrate. The mean 30-day total thrombotic event rates for andexanet alfa and prothrombin complex concentrate were 10.7% and 3.1%, respectively. Mean inhospital mortality was 23.3% for andexanet versus 15.8% for prothrombin complex concentrate. Exploratory analysis controlling for potential confounders did not demonstrate significant differences between both reversal agents.

CONCLUSIONS

Currently, available evidence does not unequivocally support the clinical effectiveness of andexanet alfa or prothrombin complex concentrate to reverse factor Xa inhibitor-associated acute major bleeding, nor does it permit conventional meta-analysis of potential superiority. Neither reversal agent was significantly associated with increased effectiveness or a higher rate of venous thromboembolic event. These results underscore the importance of randomized controlled trials comparing the two reversal agents and may provide guidance in designing institutional guidelines.

Comparison of high- and low-dose 4-factor prothrombin complex concentrate for the emergent reversal of oral Factor Xa inhibitors

Even though there are several reversal strategies available for oral Factor Xa inhibitor associated coagulopathies, 4-factor prothrombin complex concentrate (4F-PCC) is used commonly as the primary reversal agent at many institutions. A dose of 50 units/kg is recommended as safe and effective with growing data suggesting that a lower dosing strategy may be sufficient. This retrospective study included adult patients who received either high-dose (50 units/kg; maximum dose: 5000 units) or low-dose (25 units/kg; maximum dose: 2500 units) 4F-PCC for the emergent reversal of oral Factor Xa inhibitor-related life threatening bleeding. The primary outcome was the attainment of hemostatic effectiveness. Secondary outcomes were rates of thromboembolic events and inpatient mortality. 47 patients were included in the analysis of which 24 patients received high-dose and 23 patients received low-dose 4F-PCC. Overall hemostatic effectiveness was 87.5% in the high-dose group and 91.3% in the low-dose group. Thromboembolic event rate was 8.3% in the high-dose group compared to 4.4% within the low-dose group and inpatient mortality rate was 8.3% in the high-dose group and 4.4% in the low-dose group. Low-dose 4F-PCC (25 units/kg, maximum dose: 2500 units) for the reversal of oral Factor Xa inhibitors is a cost-effective alternative to high-dose 4F-PCC (50 units/kg; maximum dose: 5000 units) and provides effective hemostasis without increased rates of thromboembolic events or inpatient mortality.

Four-factor Prothrombin Complex Concentrate for Reversal of Factor Xa Inhibitors versus Warfarin in Life-threatening Bleeding

INTRODUCTION

Factor Xa (fXa) inhibitor reversal for life-threatening bleeding is controversial due to a lack of high-quality evidence. The purpose of this study was to determine the hemostatic efficacy of four-factor prothrombin complex concentrate (4F-PCC) for the reversal of fXa inhibitors compared to warfarin for life-threatening bleeding.

METHODS

This was a multicenter, retrospective cohort study at two academic medical centers between January 1, 2014-December 31, 2019, which included patients who presented to the emergency department with a life-threatening bleed necessitating anticoagulation reversal with 4F-PCC. The primary endpoint was achievement of hemostatic efficacy after 4F-PCC administration.

RESULTS

Of the 525 patients who had an order for 4F-PCC during the study period, 148 patients met the criteria for inclusion (n = 48 fXa inhibitor group; n = 100 warfarin group). Apixaban (52.1%) and rivaroxaban (45.8%) were the most commonly used fXa inhibitors. Effective hemostasis was similar between groups (79.2% fXa inhibitor group vs 85% warfarin group, p = 0.38). This was consistent across all types of bleeding. Thrombotic events were rare in both groups (2% vs 3%).

CONCLUSION

This multicenter, retrospective cohort study demonstrated that using 4F-PCC for treatment of life-threatening bleeding produced effective hemostasis in patients on fXa inhibitors and warfarin.

Recommendations for Research Assessing Outcomes for Patients With Anticoagulant-Related Intracerebral Bleeds

Intracerebral bleeds related to anticoagulant use have a poor prognosis and substantial risk of disability and death. Recent publications evaluating replacement or reversal therapies for anticoagulants lack consistency in controlling for key factors that significantly influence outcomes. In an effort to guide future research by providing a framework to improve consistency and reduce the potential for confounding in this dynamic and highly time-dependent brain insult, we provide here a brief overview of variables we consider critical in studies evaluating the risk and the reversal of anticoagulant therapies in anticoagulant-related intracerebral bleeds. Hematoma expansion stands out as one of the few potentially modifiable risk factors and its early control could mitigate secondary brain injury, and it, therefore, requires careful categorization. In addition to the baseline demographic, clinical, and radiological predictors of hematoma expansion, we specifically highlight time-dependent factors such as the time from the last dose, time from symptom onset and time to treatment, the computed tomography angiography spot sign, and the limitation of early care as especially critical predictors of outcomes in anticoagulant-related intracerebral bleeds. Intracerebral hemorrhage is a condition that requires fast diagnosis and treatment, especially when associated with anticoagulants. The advent of therapies with rapid reversal of anticoagulation open the opportunity to assess the scale to which faster reversal of anticoagulation modifies hematoma expansion and clinical outcomes. Thus, comprehensive assessment and reporting of these important potential confounding factors, particularly the critical time variables, is crucial to improving research and treatment of intracerebral hemorrhages.

Clinical Characteristics and Outcomes Associated With Oral Anticoagulant Use Among Patients Hospitalized With Intracerebral Hemorrhage

IMPORTANCE

Although the use of factor Xa (FXa) inhibitors has increased substantially over the past decade, there are limited data on characteristics and outcomes of FXa inhibitor-associated intracerebral hemorrhage (ICH).

OBJECTIVE

To investigate the association between prior oral anticoagulant use (FXa inhibitors, warfarin, or none) and in-hospital outcomes among patients with nontraumatic ICH.

DESIGN, SETTING, AND PARTICIPANTS

This is a cohort study of 219 701 patients with nontraumatic ICH admitted to 1870 hospitals in the Get With The Guidelines-Stroke registry between October 2013 and May 2018. Data analysis was performed in December 2019.

EXPOSURES

Anticoagulation therapy before ICH.

MAIN OUTCOMES AND MEASURES

The primary outcome was in-hospital mortality. Secondary outcomes were a composite measure of in-hospital mortality or discharge to hospice, discharge home, independent ambulation, and modified Rankin Scale (mRS) score at discharge.

RESULTS

Of 219 701 patients (mean [SD] age, 68.2 [15.3] years; 104 940 women [47.8%]), 9202 (4.2%) were taking FXa inhibitors, 21 430 (9.8%) were taking warfarin, and 189 069 (86.0%) were not taking any oral anticoagulant before ICH. Patients taking FXa inhibitors or warfarin were older and had higher prevalence of cardiovascular risk factors. Compared with those not taking an oral anticoagulant (42 660 of 189 069 patients [22.6%]), the in-hospital mortality risk was higher for both FXa inhibitors (2487 of 9202 patients [27.0%]; adjusted odds ratio [aOR], 1.27; 95% CI, 1.20-1.34; P < .001) and warfarin (7032 of 21 430 patients [32.8%]; aOR, 1.67; 95% CI, 1.60-1.74; P < .001). Both FXa inhibitors (3478 of 9202 patients [37.8%]; aOR, 1.19; 95% CI, 1.13-1.26; P < .001) and warfarin (9151 of 21 430 patients [42.7%]; aOR, 1.50; 95% CI, 1.44-1.56; P < .001) were associated with higher odds of death or discharge to hospice compared with not taking oral anticoagulation (58 022 of 189 069 patients [30.7%]). Although the rates of discharge home, independent ambulation, mRS scores of 0 or 1, and mRS scores of 0 to 2 were numerically lower among patients taking FXa inhibitors, these differences were not significant compared with patients not taking oral anticoagulants. In contrast, patients taking FXa inhibitors were less likely to die (aOR, 0.76; 95% CI, 0.72-0.81; P < .001) or to experience death or discharge to hospice (aOR, 0.79; 95% CI, 0.75-0.84; P < .001), more likely to be discharged home (aOR, 1.18; 95% CI, 1.10-1.26; P < .001), and had better mRS scores at discharge (eg, mRS scores of 0-1: aOR, 1.24; 95% CI, 1.09-1.40; P < .001) than those treated with warfarin. Concomitant warfarin and antiplatelet therapy (either single or dual) was associated with worse outcomes compared with taking warfarin alone (eg, in-hospital mortality for dual-antiplatelet agents: aOR, 2.07; 95% CI, 1.72-2.50; P < .001). However, such incremental risk was not significant in patients taking FXa inhibitors.

CONCLUSIONS AND RELEVANCE

In this cohort study, FXa inhibitor-associated ICH was associated with higher risk of mortality or death or discharge to hospice than not taking an oral anticoagulant, but patients taking FXa inhibitors had better outcomes than those with warfarin-related ICH.

Andexanet Alfa Versus 4-Factor Prothrombin Complex Concentrate for Reversal of Factor Xa Inhibitors in Intracranial Hemorrhage

BACKGROUND/OBJECTIVE

There are limited data on the risks and benefits of using andexanet alfa (AA) in comparison with four-factor prothrombin complex concentrate (4F-PCC) to reverse factor Xa inhibitors (FXi) associated intracranial hemorrhage (ICH). We sought to describe our experience with AA or 4F-PCC in patients with oral FXi-related traumatic and spontaneous ICH.

METHODS

We conducted a retrospective review of consecutive adult patients with FXi-related ICH who received AA or 4F-PCC. FXi-related ICH cases included traumatic and spontaneous intracranial hemorrhages. Our primary analysis evaluated ICH stability on head computed tomography scan (CT), defined as a similar amount of blood from the initial scan at the onset of ICH to subsequent scans, at 6-h and 24-h post-administration of AA or 4F-PCC. For the subset of spontaneous intraparenchymal hemorrhages, volume was measured at 6-h and 24-h post-reversal. In secondary analyses, we evaluated good functional outcome at discharge, defined as a Modified Rankin Score of less than 3, and the incidence of thrombotic events after AA or 4F-PCC adminstration, during hospitalization.

RESULTS

A total of 44 patients (16 traumatic and 28 spontaneous ICH) with median age of 79 years [72-86], 36% females, with a FXi-related ICH, were included in this study. The majority of spontaneous ICHs were intraparenchymal 19 (68%). Twenty-eight patients (64%) received AA and 16 patients (36%) received 4F-PCC. There was no difference between AA and 4F-PCC in terms of CT stability at 6 h (21 [78%] vs 10 [71%], p = 0.71) and 24 h (15 [88%] vs 6 [60%], p = 0.15). In a subgroup of patients with spontaneous intraparenchymal hemorrhage, there was no difference in the degree of achieved hemostasis based on hematoma volume between AA and 4F-PCC at 6 h (9.3 mL [6.9-26.4] vs 10 mL [9.4-22.1], adjusted p = 0. 997) and 24-h (9.2 mL [6.1-18.8] vs 9.9 [9.4-21.1], adjusted p = 1). The number of patients with good outcome based on mRS on discharge were 10 (36%) and 6 (38%) in the AA and 4F-PCC groups, respectively (adjusted p = 0.81). The incidence of thromboembolic events was similar in the AA and 4F-PCC groups (2 [7%] vs 0, p = 0.53).

CONCLUSION

In this limited sample of patients, we found no difference in neuroimaging stability, functional outcome and thrombotic events when comparing AA and 4F-PCC in patients with FXi-related ICH. Since our analysis is likely underpowered, a multi-center collaborative network devoted to this question is warranted.

Major publications in the critical care pharmacotherapy literature: 2019

PURPOSE

To summarize selected meta-analyses and trials related to critical care pharmacotherapy published in 2019.

MATERIALS AND METHODS

The Critical Care Pharmacotherapy Literature Update (CCPLU) Group screened 36 journals monthly for impactful articles and reviewed 113 articles during 2019 according to Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) criteria.

RESULTS

Articles with a 1A grade, including three clinical practice guidelines, six meta-analyses, and five original research trials are reviewed here from those included in the monthly CCPLU. Clinical practice guidelines on the use of polymyxins and antiarrhythmic drugs in cardiac arrest as well as meta-analyses on antipsychotic use in delirium, stress ulcer prophylaxis (SUP), and vasoactive medications in septic shock and cardiac arrest were summarized. Original research trials evaluated delirium, sedation, neuromuscular blockade, SUP, anticoagulation reversal, and hemostasis.

CONCLUSION

This clinical review and expert opinion provides summary and perspectives of clinical practice impact on influential critical care pharmacotherapy publications in 2019.

Outcomes Associated With 4-Factor Prothrombin Complex Concentrate Administration to Reverse Oral Factor Xa Inhibitors in Bleeding Patients

Compared with vitamin K antagonists (VKAs), oral factor Xa inhibitors are associated with at least equivalent efficacy and a lower incidence of major bleeding. Despite this benefit, bleeding remains the most common adverse event. Prior to the approval of andexanet alfa, alternative agents such as 4-factor prothrombin complex concentrate (4F-PCC) were utilized for reversal. This was a retrospective, descriptive study conducted on patients 18 years of age or older who received 4F-PCC for reversal of oral factor Xa inhibitors-associated bleeding. Patients were excluded if they received a VKA or dabigatran in the previous 48 hours. A subgroup analysis comparing 4F-PCC with andexanet alfa was conducted on patients who met the inclusion and exclusion criteria of the ANNEXA-4 trial. The primary end point of this study was to evaluate the incidence of hemostasis and associated dosing strategies in patients receiving 4F-PCC for reversal of oral factor Xa inhibitors-associated bleeding. Thirty-eight patients were included, and 28 patients (74%) achieved hemostasis. The median dose of 4F-PCC was 50 units/kg. In patients who achieved hemostasis, the median dose was 50 units/kg, and in those who failed to reach hemostasis, a median dose of 30 units/kg was seen. Within the subgroup analysis, there was no difference in overall rates of hemostasis between the 4F-PCC and andexanet alfa groups. Remaining a reasonable option to utilize for reversal of oral factor Xa inhibitors is 4F-PCC, especially when andexanet alfa is unavailable, with 50 units/kg appearing to be the most effective dose to achieve hemostasis. Further studies are needed to determine a preferential agent.

Andexanet versus prothrombin complex concentrates: Differences in reversal of factor Xa inhibitors in in vitro thrombin generation

BACKGROUND

Andexanet alfa (andexanet) is a modified human factor Xa (FXa) approved for anticoagulation reversal in patients with life-threatening bleeding treated with rivaroxaban or apixaban. Four-factor prothrombin complex concentrates (4F-PCCs) are approved for reversal of vitamin K antagonist-induced anticoagulation but not FXa inhibitors. The mechanism and effectiveness of 4F-PCCs for FXa inhibitor reversal are unclear.

OBJECTIVE

To investigate the mechanism and impact of 4F-PCCs on reversal of rivaroxaban and apixaban in vitro compared to andexanet.

METHODS

The effect of 4F-PCCs (or individual factors) on tissue factor-initiated thrombin generation (TF-TG) was evaluated in human plasma, with or without rivaroxaban or apixaban, and compared with andexanet under the same conditions.

RESULTS

In the TF-TG assay, 4F-PCC completely reversed warfarin anticoagulation. Andexanet normalized TF-TG over a wide range of apixaban and rivaroxaban concentrations tested (19-2000 ng/mL). However, 4F-PCC (or individual factors) was unable to normalize endogenous thrombin potential (ETP) or peak thrombin (Peak) in the presence of apixaban or rivaroxaban (75-500 ng/mL). TF-TG was only normalized by 4F-PCC at inhibitor concentrations <75 ng/mL (ETP) or <37.5 ng/mL (Peak). These data can be explained by the estimated thresholds of FXa activity required to support normal TF-TG based on the inhibitor:FXa ratios and levels of uninhibited FXa. The data are consistent with healthy volunteer studies where TF-TG is not normalized until inhibitor levels are substantially decreased.

CONCLUSIONS

Both the theoretical calculations and experimental data demonstrated that 4F-PCCs are only able to normalize TG over a low and narrow range of FXa inhibitor concentrations (<75 ng/mL).

Apixaban and rivaroxaban anti-Xa level utilization and associated bleeding events within an academic health system

Background

Oral factor Xa inhibitors (FXaI) can be administered in fixed doses without the need for routine laboratory monitoring. Anti-Xa assays can estimate anticoagulant effect for specific FXaI's. The aim of this study was to characterize anti-Xa levels in patients taking apixaban or rivaroxaban with major bleeding events.

Methods

Apixaban and rivaroxaban anti-Xa assays ordered within our hospital system from May 2016 to September 2019 were evaluated. The primary outcome was major bleeding events defined by International Society of Thrombosis and Haemostasis criteria. Median anti-Xa levels for each FXaI were calculated for those with and without major bleeding, as well as those who did and did not receive reversal agents.

Results

A total of 606 anti-Xa levels were analyzed. There were 146 major bleeding events documented, with the most common site being intracranial (63%). Median anti-Xa levels in patients with and without major bleeding were similar, whereas those on apixaban therapy who received reversal agents typically had higher anti-Xa levels (73 ng/mL vs. 153 ng/mL, p = 0.0019). Factors significantly associated with increased odds of bleeding were an age > 80 years, inappropriately high dosing regimens, and modest anti-Xa levels (100–300 ng/mL) for rivaroxaban specifically.

Conclusions

Older age and inappropriately high dosing regimens were associated with major bleeding in patients taking apixaban and rivaroxaban. Further investigation into the utility of anti-Xa levels for FXaI is warranted.

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Quantification and assessment of anticoagulation can be accomplished with factor Xa inhibitor (FXaI) specific anti-Xa levels

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Elderly patients and those on inappropriately high dosing regimens may be at an elevated risk for major bleeding

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It is unclear if elevated anti-Xa levels confer a direct increased risk for bleeding in the absence of other factors

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Anti-Xa levels are useful for confirmed or suspected bleeding, clearance for parenteral anticoagulation, and prior to an emergent procedure

Real-world management of oral factor Xa inhibitor-related bleeds with reversal or replacement agents including andexanet alfa and four-factor prothrombin complex concentrate: a multicenter study

Aim: We describe the real-world utilization and outcomes associated with managing oral factor Xa inhibitor (FXai)-related major bleeds. Materials & methods: Electronic records from 45 US hospitals were queried (ICD-10-CM billing codes D68.32, T45.515x or T45.525x) to identify major bleed hospitalizations related to FXai use. Patient demographics, bleed type (intracranial hemorrhage, gastrointestinal, critical compartment, traumatic, other), FXai taken, reversal or replacement agents administered (including andexanet alfa, four-factor prothrombin complex concentrate, fresh frozen plasma, others), in-hospital mortality and length of stay were recorded. Results: Of 3030 FXai-related hospitalizations for major bleeds, patients averaged 68 years old and 47% were women. In-hospital mortality was highest for intracranial hemorrhage (23%, n = 507) and lowest for gastrointestinal bleeds (4%, n = 1453). In-hospital mortality was lowest (4%) for bleeds managed with andexanet alfa (n = 342), compared with 10% for four-factor prothrombin complex concentrate (n = 733), 11% for fresh frozen plasma (n = 925) and 8% for both other agents (n = 794) and no agents (n = 438). Median length of stay was 5 days across all agents, while ICU length of stay was shorter andexanet alfa (2 days) compared with other agents (3 days). Conclusion: In-hospital mortality differed by bleed type and agents administered. Andexanet alfa was associated with the lowest rate of in-hospital mortality across all bleed types.