Clinical outcomes with unfractionated heparin monitored by anti-factor Xa vs. activated partial Thromboplastin time

Anticoagulant Therapy in Patients Undergoing Acute Pulmonary Embolism Interventions

Catheter-based interventions and surgical embolectomy represent alternatives to systemic fibrinolysis for patients with high-risk pulmonary embolism (PE) or those with intermediate-high-risk PE who deteriorate hemodynamically. They are indicated when systemic fibrinolysis is contraindicated or ineffective, or if obstructive shock is imminent. Extracorporeal membrane oxygenation can be added to reperfusion therapies or used alone for severe right ventricular dysfunction and cardiogenic shock. These advanced therapies complement but do not replace anticoagulation, which remains the cornerstone in PE management. This review summarizes the evidence and shares practical recommendations for the use of anticoagulant therapy before, during, and after acute PE interventions.

Discordance between aPTT and anti-Xa in monitoring heparin anticoagulation in mechanical circulatory support

AIMS

It is unclear whether activated partial thromboplastin time (aPTT) or anti-Xa is more accurate for monitoring heparin anticoagulation in mechanical circulatory support (MCS) patients. This study investigates the relationship between aPTT and anti-Xa in MCS patients and identifies predictors of discordance.

METHODS AND RESULTS

aPTT and anti-Xa were simultaneously measured in a prospective cohort of MCS patients receiving unfractionated heparin at a tertiary academic medical centre. Therapeutic aPTT and anti-Xa levels were 60-100 s and 0.3-0.7 IU/mL, respectively, and concordance was defined as both levels being subtherapeutic, therapeutic, or supratherapeutic. To identify predictors of discordance, both a machine learning random forest model and a multivariate regression model were applied to patient demographics, device type, and 14 laboratory variables; 23 001 pairs of simultaneously measured aPTT/anti-Xa were collected from 699 MCS patients. aPTT and anti-Xa were concordant in 35.5% of paired observations and discordant in 64.5% (aPTT > antiXa 61.5%; aPTT < antiXa 3.0%). Discordance with a high aPTT relative to anti-Xa (aPTT > antiXa) was associated with high INR, eGFR, and total bilirubin, as well as low platelets, haemoglobin, pre-albumin, white blood cell count, and haptoglobin. Total artificial heart and durable ventricular assist devices were more likely to be associated with aPTT > anti-Xa than temporary MCS devices.

CONCLUSIONS

aPTT and anti-Xa were frequently discordant in MCS patients receiving heparin anticoagulation. Clinical conditions common in MCS patients such as concurrent warfarin use, malnutrition, haemolysis, and thrombocytopenia, as well as durable type of MCS devices were associated with a high aPTT relative to anti-Xa.

Clinical guidance for unfractionated heparin dosing and monitoring in critically ill patients

INTRODUCTION

Unfractionated heparin is a widely used anticoagulant in critically ill patients. It has a well-established safety profile and remains an attractive option for clinicians due to its short half-life and reversibility. Heparin has a unique pharmacokinetic profile, which contributes to significant inter-patient and intra-patient variability in effect. The variability in anticoagulant effect combined with heparin's short half-life mean close monitoring is required for clinical efficacy and preventing adverse effects. To optimize heparin use in critically ill patients, effective monitoring assays and dose adjustment strategies are needed.

AREAS COVERED

This paper explores the use of heparin as an anticoagulant and optimal approaches to monitoring in critically ill patients.

EXPERT OPINION

Conventional monitoring assays for heparin dosing have significant limitations. Emerging data appear to favor using anti-Xa assay monitoring for heparin anticoagulation, which many centers have successfully adopted as the standard. The anti-Xa assay appears have important benefits relative to the aPTT for heparin monitoring in critically ill patients, and should be considered for broader use.

The 2023 WSES guidelines on the management of trauma in elderly and frail patients

BACKGROUND

The trauma mortality rate is higher in the elderly compared with younger patients. Ageing is associated with physiological changes in multiple systems and correlated with frailty. Frailty is a risk factor for mortality in elderly trauma patients. We aim to provide evidence-based guidelines for the management of geriatric trauma patients to improve it and reduce futile procedures.

METHODS

Six working groups of expert acute care and trauma surgeons reviewed extensively the literature according to the topic and the PICO question assigned. Statements and recommendations were assessed according to the GRADE methodology and approved by a consensus of experts in the field at the 10th international congress of the WSES in 2023.

RESULTS

The management of elderly trauma patients requires knowledge of ageing physiology, a focused triage, including drug history, frailty assessment, nutritional status, and early activation of trauma protocol to improve outcomes. Acute trauma pain in the elderly has to be managed in a multimodal analgesic approach, to avoid side effects of opioid use. Antibiotic prophylaxis is recommended in penetrating (abdominal, thoracic) trauma, in severely burned and in open fractures elderly patients to decrease septic complications. Antibiotics are not recommended in blunt trauma in the absence of signs of sepsis and septic shock. Venous thromboembolism prophylaxis with LMWH or UFH should be administrated as soon as possible in high and moderate-risk elderly trauma patients according to the renal function, weight of the patient and bleeding risk. A palliative care team should be involved as soon as possible to discuss the end of life in a multidisciplinary approach considering the patient's directives, family feelings and representatives' desires, and all decisions should be shared.

CONCLUSIONS

The management of elderly trauma patients requires knowledge of ageing physiology, a focused triage based on assessing frailty and early activation of trauma protocol to improve outcomes. Geriatric Intensive Care Units are needed to care for elderly and frail trauma patients in a multidisciplinary approach to decrease mortality and improve outcomes.

Effectiveness, Safety, and Costs of Thromboprophylaxis with Enoxaparin or Unfractionated Heparin Among Medical Inpatients With Chronic Obstructive Pulmonary Disease or Heart Failure

Background: Chronic obstructive pulmonary disease (COPD) and heart failure (HF) are risk factors for venous thromboembolism (VTE). Enoxaparin and unfractionated heparin (UFH) help prevent hospital-associated VTE, but few studies have compared them in COPD or HF. Objectives: To compare effectiveness, safety, and costs of enoxaparin vs UFH thromboprophylaxis in medical inpatients with COPD or HF. Methods: This retrospective cohort study included adults with COPD or HF from the Premier PINC AI Healthcare Database. Included patients received prophylactic-dose enoxaparin or UFH during a >6-day index hospitalization (the first visit/admission that met selection criteria during the study period) between January 1, 2010, and September 30, 2016. Multivariable regression models assessed independent associations between exposures and outcomes. Hospital costs were adjusted to 2017 US dollars. Patients were followed 90 days postdischarge (readmission period). Results: In the COPD cohort, 114 174 (69%) patients received enoxaparin and 51 011 (31%) received UFH. Among patients with COPD, enoxaparin recipients had 21%, 37%, and 10% lower odds of VTE, major bleeding, and in-hospital mortality during index admission, and 17% and 50% lower odds of major bleeding and heparin-induced thrombocytopenia (HIT) during the readmission period, compared with UFH recipients (all P <.006). In the HF cohort, 58 488 (58%) patients received enoxaparin and 42 726 (42%) received UFH. Enoxaparin recipients had 24% and 10% lower odds of major bleeding and in-hospital mortality during index admission, and 13%, 11%, and 51% lower odds of VTE, major bleeding, and HIT during readmission (all P <.04) compared with UFH recipients. Enoxaparin recipients also had significantly lower total hospital costs during index admission (mean reduction per patient: COPD, 1280 ; H F , 2677) and readmission (COPD, 379 ; H F , 1024). Among inpatients with COPD or HF, thromboprophylaxis with enoxaparin vs UFH was associated with significantly lower odds of bleeding, mortality, and HIT, and with lower hospital costs. Conclusions: This study suggests that thromboprophylaxis with enoxaparin is associated with better outcomes and lower costs among medical inpatients with COPD or HF based on real-world evidence. Our findings underscore the importance of assessing clinical outcomes and side effects when evaluating cost-effectiveness.

Evaluation of anti-Xa levels in patients with venous thromboembolism within the first 48 h of anticoagulation with unfractionated heparin

Background: A 2019 study by Prucnal and colleagues found that the majority of patients treated with unfractionated heparin for pulmonary embolism did not maintain therapeutic activated partial thromboplastin time levels during the first 48 h of therapy. Objective: The purpose of this study was to evaluate the ability of an institution's unfractionated heparin dosing protocol to achieve and maintain therapeutic anti-Xa levels within the first 48 h of therapy in patients with venous thromboembolism. Methods: This retrospective study included 205 patients from May 2016 through September 2020. Patients were divided into two cohorts: bolus plus infusion (N = 89) and infusion only (N = 116). The primary objective was to determine the number of patients who achieved at least one therapeutic level. Results: Overall, 200 patients (97.6%) had at least one therapeutic level with no statistically significant difference between cohorts (p = 0.65). No more than 60% of patients achieved a therapeutic level at any of the 6-h intervals throughout the timeframe. The median time to the first therapeutic level in the overall group was 12.8 h with no statistically significant difference between the bolus plus infusion and infusion-only cohorts (13.3 h versus 12.7 h, respectively, p = 0.48). Conclusions: Most patients were able to achieve at least one therapeutic level within the first 48 h, but fewer were able to maintain therapeutic levels. Further studies are warranted to determine whether alternative dosing strategies would yield consistent achievement of therapeutic levels and affect patient-oriented outcomes.

Effectiveness, safety, and costs of thromboprophylaxis with enoxaparin or unfractionated heparin in inpatients with obesity

Background

Obesity is a frequent and significant risk factor for venous thromboembolism (VTE) among hospitalized adults. Pharmacologic thromboprophylaxis can help prevent VTE, but real-world effectiveness, safety, and costs among inpatients with obesity are unknown.

Objective

This study aims to compare clinical and economic outcomes among adult medical inpatients with obesity who received thromboprophylaxis with enoxaparin or unfractionated heparin (UFH).

Methods

A retrospective cohort study was performed using the PINC AI™ Healthcare Database, which covers more than 850 hospitals in the United States. Patients included were ≥18 years old, had a primary or secondary discharge diagnosis of obesity [International Classification of Diseases (ICD)-9 diagnosis codes 278.01, 278.02, and 278.03; ICD-10 diagnosis codes E66.0x, E66.1, E66.2, E66.8, and E66.9], received ≥1 thromboprophylactic dose of enoxaparin (≤40 mg/day) or UFH (≤15,000 IU/day) during the index hospitalization, stayed ≥6 days in the hospital, and were discharged between 01 January 2010, and 30 September 2016. We excluded surgical patients, patients with pre-existing VTE, and those who received higher (treatment-level) doses or multiple types of anticoagulants. Multivariable regression models were constructed to compare enoxaparin with UFH based on the incidence of VTE, pulmonary embolism (PE)---------related mortality, overall in-hospital mortality, major bleeding, treatment costs, and total hospitalization costs during the index hospitalization and the 90 days after index discharge (readmission period).

Results

Among 67,193 inpatients who met the selection criteria, 44,367 (66%) and 22,826 (34%) received enoxaparin and UFH, respectively, during their index hospitalization. Demographic, visit-related, clinical, and hospital characteristics differed significantly between groups. Enoxaparin during index hospitalization was associated with 29%, 73%, 30%, and 39% decreases in the adjusted odds of VTE, PE-related mortality, in-hospital mortality, and major bleeding, respectively, compared with UFH (all p < 0.002). Compared with UFH, enoxaparin was associated with significantly lower total hospitalization costs during the index hospitalization and readmission periods.

Conclusions

Among adult inpatients with obesity, primary thromboprophylaxis with enoxaparin compared with UFH was associated with significantly lower risks of in-hospital VTE, major bleeding, PE-related mortality, overall in-hospital mortality, and hospitalization costs.

Perioperative Assessment and Optimization in Major Colorectal Surgery: Medication Management

The colorectal surgeon is often faced with medications that can be challenging to manage in the perioperative period. In the era of novel agents for anticoagulation and immunotherapies for inflammatory bowel disease and malignancy, understanding how to advise patients about these medications has become increasingly complex. Here, we aim to provide clarity regarding the use of these agents and their perioperative management, with a particular focus on when to stop and restart them perioperatively. This review will begin with the management of both nonbiologic and biologic therapies used in the treatment of inflammatory bowel disease and malignancy. Then, discussion will shift to anticoagulant and antiplatelet medications, including their associated reversal agents. Upon finishing this review, the reader will have gained an increased familiarity with the management of common medications requiring modification by colorectal surgeons in the perioperative period.

An Evaluation of Time to Therapeutic Range of Intravenous Unfractionated Heparin After Transitioning From Direct Oral Factor Xa Inhibitors

Purpose: Direct oral factor Xa inhibitors (Xa inhibitor) may falsely elevate anti-Xa assays, creating a challenge when patients transition from Xa inhibitors to intravenous unfractionated heparin (IV UFH). This study compared the time to therapeutic anti-Xa range in patients transitioning from Xa inhibitors to IV UFH to those not previously anticoagulated and initiated on IV UFH. Methods: This single-center, retrospective study included adults receiving IV UFH from August 2018 through August 2019. The study group received apixaban or rivaroxaban prior to the initiation of IV UFH, and the control group was not previously anticoagulated. The primary outcome was the time to reach therapeutic range. Secondary outcomes included the number of anti-Xa levels drawn to reach therapeutic range, incidence of treatment failure, and incidence of major bleeding episodes. Categorical and continuous data were analyzed with chi-square and Mann-Whitney U tests, respectively. Results: The time to reach therapeutic range was a median of 18.5 hours in the study group (IQR 14.9-26.9) compared to 7.3 hours (IQR 5.9-14.7) in the control group (P < .001). Two anti-Xa levels were drawn in the study group (IQR 1-4) compared to 1 (IQR 1-2) in the control group (P < .001). There was no difference in the incidence of treatment failures (P = .981) or major bleeding episodes (P = .972). Conclusions: In patients transitioning from Xa inhibitors to IV UFH, the time to therapeutic range was longer and required additional laboratory tests compared to those not previously anticoagulated. Further research is needed to examine the incidence of treatment failures or major bleeding episodes.

Application of anti-Xa assay in monitoring unfractionated heparin therapy in contemporary antithrombotic management

INTRODUCTION

Unfractionated heparin remains the most widely used agent in the prevention and acute treatment of thrombosis. Pharmacological complexities of this intriguing agent mandate frequent monitoring of its anticoagulant properties to maintain safe and effective hematological outcomes. Although activated partial thromboplastin time has been the standard test to monitor unfractionated heparin therapy for many decades, the anti-Xa assay has emerged as a substitute or adjunct in many institutions.

AREAS COVERED

This brief report outlines the key features of anti-Xa assay in monitoring unfractionated heparin in acute management of thrombosis in various contemporary settings, with emphasis on evidence for clinical outcomes. PubMed.gov database was utilized to obtain the pertinent literature.

EXPERT OPINION

The anti-Xa activity is primarily a reflection of UFH concentration and does not account for other hematological variables frequently present in contemporary anticoagulation management. The advantage of the anti-Xa assay in monitoring UFH therapy is predicated upon its limitations to account for global physiological hemostasis. There are significant disease and drug interactions that may potentially result in false in-vitro analysis of anti-Xa activity. Routine application of the anti-Xa assay is not evidence-based at this time.

Comparison of Managing Factor Xa Inhibitor to Unfractionated Heparin Transitions by aPTT Versus a Treatment Guideline Utilizing Heparin Anti-Xa Levels

BACKGROUND

There are inadequate data on the optimal strategy for transitioning factor Xa inhibitors (FXai; apixaban, rivaroxaban) to unfractionated heparin (UFH) infusions.

OBJECTIVE

In patients transitioning from an FXai to an UFH infusion, this study compared the safety and efficacy of monitoring UFH infusions using an activated partial thromboplastin time (aPTT) titration scale versus utilizing an UFH-calibrated anti-Xa titration scale aided by a novel institutional guideline.

METHODS

A retrospective cohort analysis was conducted on adult patients transitioning from an FXai to an UFH infusion at 2 medical centers from June 1, 2018, to November 1, 2020. One institution utilized aPTT while the other institution primarily used UFH-calibrated anti-Xa. The primary endpoint was a composite of death, major bleeding, or new thrombosis during the hospitalization with a planned noninferiority analysis. Secondary outcomes were also collected including the amount and duration of UFH administered between cohorts.

RESULTS

The incidence rate of the primary composite endpoint was 6.3% in the anti-Xa group and 11% in the aPTT group (P < 0.001 for noninferiority, P = 0.138 for superiority) meeting noninferiority criteria. No statistical differences were seen in new thrombosis, major bleeding, or any bleeding.

CONCLUSION AND RELEVANCE

This represents the first report of a comparison between aPTT versus anti-Xa monitoring in relation to clinical outcomes for patients transitioning from an FXai to an UFH infusion. A transition guideline primarily utilizing an UFH-calibrated anti-Xa assay appears to be a safe alternative to aPTT monitoring and can aid facilities in the management of patients during these complex transitions.

Improving safety of unfractionated heparin: a retrospective, quasi-experimental, observational study of the impact of a pocket card and a computerised prescription aid tool in the University Hospitals of Geneva

BACKGROUND

Despite the rapid rise of direct oral anticoagulants, unfractionated heparin (UFH) remains the mainstay anticoagulant in specific situations such as severe renal failure, perioperative setting or in critical care units. However, its titration is often challenging.

OBJECTIVES

To investigate the effect of a pocket card and a computerised prescription aid tool (CPAT) on the quality of UFH anticoagulation.

DESIGN

Monocentric retrospective, quasi-experimental, observational study.

SETTING

Inpatient primary care centre between 1 January 2016 and 31 December 2019.

PARTICIPANTS

>18 years-old treated with therapeutic UFH for more than 24 hours. There were 819 and 1169 anticoagulation episodes before and after intervention, respectively.

INTERVENTION

In October 2017, we implemented a pocket card with evidence-based recommendation for therapeutic UFH initiation, monitoring and dosing adaptation. In October 2019, we implemented a CPAT in a group subset.

PRIMARY AND SECONDARY OUTCOMES

The primary outcome was the time needed to reach a therapeutic anti-Xa before and after the implementation of the pocket card. The secondary outcomes included a subgroup analysis assessing the effect of the CPAT. Other secondary outcomes were the anti-Xa status (infratherapeutic, therapeutic or supratherapeutic) at 7 and 24 hours of UFH treatment.

RESULTS

We found a significant increase in the time to reach therapeutic dosing with pocket card-guided recommendations implementation (10.1 vs 14 hours, HR of 0.8, 95% CI: 0.70 to 0.93). However, the CPAT was associated with a significant decrease in the time needed to reach the therapeutic range (13.9 vs 7.1 hours, HR of 1.74, 95% CI: 1.17 to 2.60).

CONCLUSION

Although we observed an increase in time to reach therapeutic anti-Xa with the pocket card, possibly due to a selection bias (use of activated partial thromboplastin time for monitoring before the pocket card), the implementation of CPAT significantly decreased the delay for effective therapy. Further studies are needed to confirm these findings, and to determine the optimal initial dose of UFH anticoagulation.

Comparison of clinical outcomes using activated partial thromboplastin time versus antifactor-Xa for monitoring therapeutic unfractionated heparin: A systematic review and meta-analysis

INTRODUCTION

Continuous intravenous unfractionated heparin (UFH) is a mainstay of therapeutic anticoagulation in the acute setting. The two most common laboratory tests for monitoring UFH are the activated partial thromboplastin time (aPTT) and antifactor Xa (anti-Xa) heparin assay. We reviewed the available evidence to evaluate if the choice of monitoring test for UFH therapy is associated with a difference in the clinical outcomes of bleeding, thrombosis, or mortality.

MATERIALS AND METHODS

MEDLINE, Cochrane database, and conference abstracts from the Society of Critical Care Medicine, the American Society of Hematology, and the American College of Clinical Pharmacy were searched for all studies comparing aPTT and anti-Xa monitoring for therapeutic UFH that evaluated outcomes for bleeding, thrombotic events, or mortality. Risk of bias was assessed with the Cochrane Risk of Bias Tool and Newcastle Ottawa Scale. Pooled relative risk ratios were calculated using an inverse variance-weighted random-effects model.

RESULTS

Ten studies (n = 6677) were included for analysis. The use of anti-Xa compared to aPTT was not associated with an increased risk of bleeding (RR 1.03; 95% CI 0.8-1.22 I² = 4%) or an increased risk of thrombotic events (RR 0.99; 95% CI 0.76-1.30, I² = 3%). There was no difference in mortality within individual studies but the data were not suitable for pooled analysis.

CONCLUSIONS

Pooled data comparing aPTT vs. anti-Xa for monitoring therapeutic UFH did not suggest differences in the outcomes of bleeding or thrombosis.

[Anticoagulation in intensive care medicine]

Critically ill patients are at high risk of hemostasis disorders, which can be associated with both an increased risk of bleeding and an increased risk of thromboembolic events. In the case of acute vascular events, specific therapy with drug anticoagulation or platelet aggregation inhibition is essential. In patients with pre-existing conditions, the appropriate continuation of anticoagulation during intensive care treatment is important. Furthermore, in everyday clinical practice, prophylaxis of thromboembolism as well as the question of potential therapeutic options in the treatment of sepsis and infection-triggered disorders of blood coagulation are important. Specific questions arise with the use of extracorporeal devices such as renal replacement and circulatory assist systems. A number of new anticoagulation and anti-platelet drugs have become available in recent years. Laboratory monitoring of anticoagulation is central. In this overview, current aspects of these topics are presented.

Updates in Anticoagulation Therapy Monitoring

In the past six decades, heparin and warfarin were the primary anticoagulants prescribed for treatment and prophylaxis of venous thromboembolism worldwide. This has been accompanied by extensive clinical knowledge regarding dosing, monitoring, and reversal of these anticoagulants, and the resources required to do so have largely been readily available at small and large centers alike. However, with the advent of newer oral and parenteral anticoagulants such as low molecular weight heparins, factor Xa inhibitors, and direct thrombin inhibitors in recent years, new corresponding practice guidelines have also emerged. A notable shift in the need for monitoring and reversal agents has evolved as well. While this has perhaps streamlined the process for physicians and is often desirable for patients, it has also left a knowledge and resource gap in clinical scenarios for which urgent reversal and monitoring is necessary. An overview of the currently available anticoagulants with a focus on the guidelines and available tests for anticoagulant monitoring will be discussed in this article.

A Pharmacotherapy Scholars Program to Provide Intensive Training to Enhance Pharmacy Students' Postgraduate Readiness

Objective. To design, integrate the curriculum for, and evaluate an innovative program to facilitate placement of students into postgraduate pharmacy residency training programs involving direct patient care. Methods. The Pharmacotherapy Scholars Program (PSP) was designed to prepare fourth-professional year students to become highly proficient in a direct patient care role and to successfully match with postgraduate residency training programs. The following elements were included in the year-long curriculum: integrated synchronous advanced pharmacy practice experiences with personal advising, team-based mentoring, peer-to-peer learning, longitudinal research, and professional development. Program goals were modeled after the accreditation standards for postgraduate year one (PGY1) pharmacy residency programs. Program faculty members ensured that the PSP had a broad scope, included rigorous student assessments, had a strong research focus, and provided scholarship opportunities. Results. Sixty-eight students completed the program from fall 2013 through spring 2019. The overall residency match rate was 93%. Students' performance on both knowledge and clinical skills assessments significantly improved after completing the program. There was an approximately 15% increase in knowledge and a 30% improvement in clinical skills based on comprehensive readiness assessments and an intermittent clinical examination that used patient simulation, respectively. Conclusion. The Pharmacotherapy Scholars Program is an innovative training program designed to enhance PharmD students' preparation for advanced clinical training. Students who completed the PSP achieved a high PGY1 residency placement rate while demonstrating significant improvements in pharmacotherapy knowledge and clinical skills in direct patient care activities.