Once versus twice daily enoxaparin for the initial treatment of acute venous thromboembolism

Enoxaparin for Long-Term Therapy of Venous Thromboembolism in Patients with Cancer and Renal Insufficiency

BACKGROUND

 The optimal therapy of venous thromboembolism (VTE) in cancer patients with renal insufficiency (RI) is unknown. Current guidelines recommend to use low-molecular-weight heparin over direct oral anticoagulants to treat VTE in cancer patients at high risk of bleeding.

METHODS

 We used the Registro Informatizado Enfermedad Tromboemb00F3lica (RIETE) registry to compare the 6-month incidence rates of (1) VTE recurrences versus major bleeding and (2) fatal pulmonary embolism (PE) versus fatal bleeding in three subgroups (those with mild, moderate, or severe RI) of cancer patients receiving enoxaparin monotherapy.

RESULTS

 From January 2009 through June 2022, 2,844 patients with RI received enoxaparin for ≥6 months: 1,432 (50%) had mild RI, 1,168 (41%) moderate RI, and 244 (8.6%) had severe RI. Overall, 68, 62, and 12%, respectively, received the recommended doses. Among patients with mild RI, the rates of VTE recurrences versus major bleeding (4.6 vs. 5.4%) and fatal PE versus fatal bleeding (1.3 vs. 1.2%) were similar. Among patients with moderate RI, VTE recurrences were half as common as major bleeding (3.1 vs. 6.3%), but fatal PE and fatal bleeding were close (1.8 vs. 1.2%). Among patients with severe RI, VTE recurrences were threefold less common than major bleeding (4.1 vs. 13%), but fatal PE was threefold more frequent than fatal bleeding (2.5 vs. 0.8%). During the first 10 days, fatal PE was fivefold more common than fatal bleeding (2.1 vs. 0.4%).

CONCLUSION

 Among cancer patients with severe RI, fatal PE was fivefold more common than fatal bleeding. The recommended doses of enoxaparin in these patients should be revisited.

Once-daily Compared With Twice-daily Enoxaparin Maintenance Therapy Appears Safe and Efficacious in Pediatric Venous Thromboembolism

INTRODUCTION

Once-daily enoxaparin (ODE), considered standard of care for venous thromboembolism (VTE) treatment in adults, has been infrequently assessed in children. To contribute available data to a limited field, we reviewed our center's experience with ODE in treating pediatric VTE compared with twice-daily enoxaparin (TDE).

MATERIALS AND METHODS

A retrospective analysis of children and adolescents 18 years of age or below diagnosed with VTE and treated at our institution with ODE or TDE maintenance therapy between April 2015 and December 2020 was performed. Patient demographics, clinical and laboratory data pertaining to VTE diagnosis, and management were gathered from electronic medical records and compared between the 2 cohorts.

RESULTS

Seventy-one children met the eligibility criteria. All patients were initially treated with TDE for 2 weeks before transitioning to ODE maintenance therapy (n=39; 55%) or continuing with TDE dosing (n=32; 45%).Extremity VTE was more common in ODE ( P =0.051) versus pulmonary/intracardiac sites in TDE ( P =0.002) when compared with other sites. Median enoxaparin dosing was 1.5 and 1.1 mg/kg/dose in ODE and TDE cohorts, respectively. Bleeding episodes were rare without any difference between the cohorts. Two patients (6%) were lost to follow up in TDE cohort. All evaluable patients in both cohorts had either complete/partial response (ODE n=35 [90%]; TDE n=24 [75%] or stable thrombus ODE n=4 [10%]; TDE n=6 [19%]).

CONCLUSIONS

Our results indicate that ODE, used after the initial TDE treatment period, is as safe and efficacious as TDE maintenance for the treatment of pediatric VTE. The difference in VTE sites may have contributed to the equal efficacy of both the cohorts. Future prospective studies in pediatric VTE are needed to validate these results.

Critical appraisal of evidence for anti-Xa monitoring and dosing of low-molecular-weight heparin in renal insufficiency

INTRODUCTION

Several guidelines advise to monitor therapeutic LMWH therapy with peak anti-Xa concentrations in renal insufficiency with subsequent dose adjustments. A better understanding of the clinical association between peak anti-Xa concentrations and clinical outcomes is mandatory, because misunderstanding this association could lead to erroneous, and potentially even harmful, LMWH dose adjustments.

AREAS COVERED

We reviewed the evidence of the widely applied therapeutic window for anti-Xa peak concentrations and report on the evidence for pharmacokinetic dose reduction in renal insufficiency, limitations of peak and trough anti-Xa concentration monitoring.

EXPERT OPINION

The added value of peak anti-Xa monitoring in patients with renal insufficiency, receiving a dose reduced for pharmacokinetic changes, is not supported by data. Enoxaparin and nadroparin should be adjusted to 50-65% and 75-85% of the original dose for patients with a creatinine clearance (CrCL) of <30 ml/min and 30-60 ml/min, respectively. Tinzaparin should be adjusted to around 50% of the original dose for patients with a CrCL of <30 ml/min. In case anti-Xa monitoring is applied, trough concentration anti-Xa monitoring is preferred over peak monitoring, aiming at a maximum concentration of 0.4 IU/mL for once-daily dosed tinzaparin and 0.5 IU/mL for twice-daily dosed enoxaparin and nadroparin.

Tinzaparin—a review of its molecular profile, pharmacology, special properties, and clinical uses

Purpose

Low molecular weight heparins (LMWHs) are a group of heterogenous moieties, long used in the prevention and treatment of thrombosis. They derive from heparin and since they are prepared by different methods of depolymerization, they differ in pharmacokinetic properties and anticoagulant profiles, and thus are not clinically interchangeable.

Methods

In this review we provide an overview of tinzaparin's main characteristics and uses.

Results

Tinzaparin which is produced by the enzymatic depolymerization of unfractionated heparin (UFH) can be used for the treatment and prevention of deep venous thrombosis (DVT) and pulmonary embolism (PE); it has been also used in special populations such as elders, obese, pregnant women, and patients with renal impairment and/or cancer with favorable outcomes in both safety and efficacy, with a once daily dose regimen. Furthermore, LMWHs are extensively used in clinical practice for both thromboprophylaxis and thrombosis treatment of COVID-19 patients.

Conclusion

Tinzaparin features support the hypothesis for having a role in immunothrombosis treatment (i.e. in the context of cancer ,COVID-19), interfering not only with coagulation cascade but also exhibiting anti-inflammatory potency.

What Do We Know about Thromboprophylaxis and Its Monitoring in Critically Ill Patients?

Venous thromboembolism (VTE), including deep vein thrombosis and pulmonary embolism, is an important complication in patients hospitalized in intensive care units (ICU). Thromboprophylaxis is mainly performed with Low Molecular Weight Heparin (LMWH) and, in some specific patients, with Unfractionated Heparin (UFH). These intensive units are an environment where individual patient variability is extreme and where traditional antithrombotic protocols are frequently ineffective. This was known for a long time, but the hospitalization of many patients with COVID-19 inflammatory storms suddenly highlighted this knowledge. It is therefore reasonable to propose variable antithrombotic prevention protocols based initially on a series of individual criteria (weight, BMI, and thrombotic risks). Secondly, they should be adjusted by the monitoring of anticoagulant activity, preferably by measuring the anti-Xa activity. However, we still face unresolved questions, such as once- or twice-daily LMWH injections, monitoring at the peak and/or trough, and poorly defined therapeutic targets. Equally surprisingly, we observed a lack of standardization of the anti-Xa activity kits.

Once-daily vs. twice-daily dosing of enoxaparin for the management of venous thromboembolism: A systematic review and meta-analysis

The present study aimed to determine whether there is any difference in the efficacy and safety of once-daily vs. twice-daily enoxaparin when used for the initial treatment of venous thromboembolism (VTE). The PubMed, Embase, Cochrane Central Register of Controlled Trials, Science Direct and Google Scholar databases were searched for studies comparing once-daily and twice-daily enoxaparin for the initial treatment of VTE added from inception up to 1st October 2019. Studies utilizing any other low-molecular-weight heparin and using enoxaparin for VTE prophylaxis were excluded. A total of 6 studies were included in the systematic review and 5 in the meta-analysis. Only one study was a randomized controlled trial (RCT). Pooled analysis of 460 patients receiving once-daily enoxaparin and 464 patients receiving twice-daily enoxaparin indicated no significant difference between the two dosing regimens regarding VTE recurrence [odds ratio (OR)=1.48, 95%CI: 0.75-2.89, P=0.26; I²=0%]. No significant difference in major hemorrhagic complications was noted (OR=1.21, 95%CI: 0.52-2.81, P=0.66; I²=0%). Sub-group analysis based on study type and use of enoxaparin for bridging therapy did not change the overall results. In cancer patients, no statistically significant difference in the recurrence of VTE was obtained between once-daily and twice-daily enoxaparin, but the confidence intervals were wide with a tendency to favor twice-daily dosing (OR=2.28, 95%CI: 0.91-5.75, P=0.08; I²=0%). The overall quality of the studies was determined to be average. To conclude, while the present results suggested no significant difference in efficacy and safety of once-daily vs. twice-daily enoxaparin when used for the initial treatment of VTE, the quality of the evidence may not have been sufficiently high to support the conclusions with confidence. Further high-quality and adequately powered RCTs are required to corroborate the present results.

Comparison of All-Cause Mortality Following VTE Treatment Between Propensity Score-Adjusted Observational Studies and Matched Randomized Controlled Trials: Meta-Epidemiologic Study

BACKGROUND

It is unknown whether propensity score-adjusted observational studies produce results comparable to those of randomized controlled trials (RCTs) that address similar VTE treatment issues.

METHODS

The PubMed and Web of Science databases were systematically searched for propensity score-adjusted observational studies, RCTs, and meta-analyses of RCTs that estimated all-cause mortality following VTE treatment. After identifying distinct clinical treatment issues evaluated in the eligible observational studies, a standardized algorithm was used to identify and match at least one RCT or RCT meta-analysis publication for paired study design analyses. Meta-analyses were used to summarize groups of studies. Treatment efficacy statistics (relative ORs) were compared between the paired observational and RCT studies, and the summary relative ORs for all study design pairs were also calculated.

RESULTS

The observational and RCT study pairs assessed seven clinical treatment issues. Overall, the observational study-RCT pairs did not exhibit significantly different mortality estimates (summary relative OR, 0.89; 95% CI, 0.32-1.46; I² = 23%). However, two of the seven treatment issue study pairs (thrombolysis vs anticoagulation for pulmonary embolism; once- vs twice-daily enoxaparin for VTE) exhibited a significantly different treatment effect direction, and there was a substantial (nonsignificant) difference in the magnitude of the effect in another two of the study pairs (rivaroxaban vs vitamin K antagonists for VTE; home treatment vs hospitalization for DVT).

CONCLUSIONS

This systematic comparison across seven VTE treatment topics suggests that propensity score-adjusted observational studies and RCTs often exhibit similar all-cause mortality, although differences in the direction or the magnitude of estimated treatment effects may occasionally occur.

TRIAL REGISTRY

PROSPERO; CRD42018087819; URL: http://www.crd.york.ac.uk/PROSPERO.

Once-Daily Versus Twice-Daily Enoxaparin for the Treatment of Acute Venous Thromboembolism in Cancer Patients

BACKGROUND

No randomized controlled trials have investigated enoxaparin once versus twice daily for venous thromboembolism (VTE) treatment in cancer patients.

OBJECTIVE

To compare the safety and efficacy of enoxaparin 1 mg/kg twice daily versus enoxaparin 1.5 mg/kg/day for the treatment of acute VTE in cancer patients.

METHODS

This was a single-center, retrospective, observational cohort study. Adults with active cancer and an acute VTE were included. The primary outcome evaluated was the incidence of clinically relevant (major and nonmajor) bleeding (CRB) within 30 days of enoxaparin initiation. Secondary outcomes included the incidence of CRB, thrombosis, and death at 30, 90, and 180 days. The study protocol was approved by the institutional review board.

RESULTS

A total of 123 patients met inclusion criteria; 85 patients (69%) were treated with once-daily and 38 patients (31%) with twice-daily enoxaparin. CRB was numerically higher at 30 days in the twice-daily enoxaparin group compared with the once-daily group (5.3% vs 2.4%, P = 0.587). There was a nonsignificant higher incidence of CRB in the once-daily enoxaparin group compared with the twice-daily group at 90 days (8.3% vs 8%, P = 1.0) and 180 days (12.5% vs 7.1%, P = 1.0). The composite outcome of CRB, thrombosis, and death was higher at all time points with enoxaparin once daily.

CONCLUSIONS

Lack of statistical power in this study precludes definitive conclusions. Clinicians may consider twice-daily enoxaparin because of potentially fewer adverse events but may be limited by patient preference and/or financial constraints.

Major bleeding risks of different low-molecular-weight heparin agents: a cohort study in 12 934 patients treated for acute venous thrombosis

Essentials Low-molecular-weight-heparins (LMWH) kinetics differ which may result in different bleeding risks. A cohort of 12 934 venous thrombosis patients on LMWH was followed until major bleeding. The absolute major bleeding risk was low among patients registered at the anticoagulation clinic. Once-daily dosing was associated with a lower bleeding risk as compared with twice-daily.

SUMMARY

Background Low-molecular-weight heparins (LMWHs) are considered members of a class of drugs with similar anticoagulant properties. However, pharmacodynamics and pharmacokinetics between LMWHs differ, which may result in different bleeding risks. As these agents are used by many patients, small differences may lead to a large effect on numbers of major bleeding events. Objectives To determine major bleeding risks for different LMWH agents and dosing schedules. Methods A cohort of acute venous thrombosis patients from four anticoagulation clinics who used an LMWH and a vitamin K antagonist were followed until they ceased LMWH treatment or until major bleeding. Exposures were classified according to different types of LMWHs and for b.i.d. and o.d. use. Cumulative incidences for major bleeding per 1000 patients and risk ratios were calculated and adjusted for study center. Results The study comprised 12 934 patients with a mean age of 59 years; 6218 (48%) were men. The cumulative incidence of major bleeding was 2.5 per 1000 patients (95% confidence interval [CI], 1.7-3.5). Enoxaparin b.i.d. or o.d. was associated with a relative bleeding risk of 1.7 (95% CI, 0.2-17.5) compared with nadroparin o.d. In addition, a nadroparin b.i.d. dosing schedule was associated with a 2.0-fold increased major bleeding risk (95% CI, 0.8-5.1) as compared with a nadroparin o.d. dosing schedule. Conclusions Absolute major bleeding rates were low for all LMWH agents and dosing schedules in a large unselected cohort. Nevertheless, twice-daily dosing with nadroparin appeared to be associated with an increased major bleeding risk as compared with once-daily dosing, as also suggested in a meta-analysis of controlled clinical trials.