Enoxaparin vs heparin for prevention of deep-vein thrombosis in acute ischaemic stroke: a randomized, double-blind study

Incidence of Symptomatic Venous Thromboembolisms in Stroke Patients

Venous thromboembolism (VTE) is a common but preventable complication observed in critically ill patients. Deep vein thrombosis (DVT) is the most common type of VTE, with clinical significance based on location and symptoms. There is an increased incidence of DVT and pulmonary embolism (PE) in ischemic stroke patients using unfractionated heparin (UFH) for VTE prophylaxis compared with those using enoxaparin. However, UFH is still used in some patients due to its perceived safety, despite conflicting literature suggesting that enoxaparin may have a protective effect. The current study aimed to determine the incidence of VTEs in patients with acute ischemic strokes on UFH versus enoxaparin for VTE prophylaxis, subclassifying the VTEs depending on their location and symptoms. It also aimed to examine the safety profile of both drugs. A total of 909 patients admitted to the Neuro-ICU with the diagnosis of acute ischemic stroke were identified, and 634 patients were enrolled in the study-170 in the enoxaparin group and 464 in the UFH group-after applying the exclusion criteria. Nineteen patients in the UFH group (4.1%) and 3 patients in the enoxaparin group (1.8%) had a VTE. The incidence of DVT in the UFH group was 12 (2.6%), all of which were symptomatic, compared with 3 (1.8%) in the enoxaparin group, wherein one case was symptomatic. Nine patients (1.9%) in the UFH group developed a PE during the study period, and all of them were symptomatic. No patients in the enoxaparin group developed PE. No statistically significant difference was found between both groups. However, 18 patients in the UFH group (3.9%) experienced intracranial hemorrhage compared with none in the enoxaparin group, and this difference was statistically significant. Enoxaparin was found to be as effective as and potentially safer than UFH when used for VTE prophylaxis in stroke patients.

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.

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.

Enoxaparin may be associated with lower rates of mortality than unfractionated heparin in neurocritical and surgical patients

Unfractionated heparin (UFH) and low molecular weight heparin (LMWH) are often administered to prevent venous thromboembolism (VTE) in critically ill patients. However, the preferred prophylactic agent (UFH or LMWH) is not known. We compared the all-cause mortality rate in patients receiving UFH to LMWH for VTE prophylaxis. We conducted a retrospective propensity score adjusted analysis of patients admitted to neuro-critical, surgical, or medical intensive care units. Patients were included if they were screened with venous duplex ultrasonography or computed tomography angiography for detection of VTE. The primary outcome was all-cause mortality. Secondary outcomes included the prevalence of VTE, deep vein thrombosis (DVT), pulmonary embolism (PE), and hospital length of stay (LOS). Initially 2228 patients in the cohort were included for analysis, 1836 (82%) patients received UFH, and 392 (18%) patients received enoxaparin. After propensity score matching, a well-balanced cohort of 618 patients remained in the study (309 patients receiving UFH; 309 patients receiving enoxaparin). The use of UFH for VTE prophylaxis in ICU patients was associated with similar rates of all-cause mortality compared with enoxaparin [RR 0.73; 95% CI 0.43-1.24, p = 0.310]. There were no differences in the prevalence of DVT, prevalence of PE or hospital LOS between the two groups, DVT [RR 0.93; 95% CI 0.56-1.53, p = 0.889], PE [RR 1.50; 95% CI 0.78-2.90, p = 0.296] and LOS [9 ± 9 days vs 9 ± 8; p = 0.857]. A trend toward mortality benefit was observed in NICU [RR 0.37; 95% CI 0.13-1.07, p = 0.062] and surgical patients [RR 0.43; 95% CI 0.17-1.02, p = 0.075] favoring the enoxaparin group. The use of UFH for VTE prophylaxis in ICU patients was associated with similar rates of VTE, all-cause mortality and LOS compared to enoxaparin. In subgroup analysis, neuro-critical and surgical patients who received UFH had a higher rate of mortality than those who received enoxaparin.

Anticoagulants for thrombosis prophylaxis in acutely ill patients admitted to hospital: systematic review and network meta-analysis

OBJECTIVE

To assess the benefits and harms of different types and doses of anticoagulant drugs for the prevention of venous thromboembolism in patients who are acutely ill and admitted to hospital.

DESIGN

Systematic review and network meta-analysis.

DATA SOURCES

Cochrane CENTRAL, PubMed/Medline, Embase, Web of Science, clinical trial registries, and national health authority databases. The search was last updated on 16 November 2021.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Published and unpublished randomised controlled trials that evaluated low or intermediate dose low-molecular-weight heparin, low or intermediate dose unfractionated heparin, direct oral anticoagulants, pentasaccharides, placebo, or no intervention for the prevention of venous thromboembolism in acutely ill adult patients in hospital.

MAIN OUTCOME MEASURES

Random effects, bayesian network meta-analyses used four co-primary outcomes: all cause mortality, symptomatic venous thromboembolism, major bleeding, and serious adverse events at or closest timing to 90 days. Risk of bias was also assessed using the Cochrane risk-of-bias 2.0 tool. The quality of evidence was graded using the Confidence in Network Meta-Analysis framework.

RESULTS

44 randomised controlled trials that randomly assigned 90 095 participants were included in the main analysis. Evidence of low to moderate quality suggested none of the interventions reduced all cause mortality compared with placebo. Pentasaccharides (odds ratio 0.32, 95% credible interval 0.08 to 1.07), intermediate dose low-molecular-weight heparin (0.66, 0.46 to 0.93), direct oral anticoagulants (0.68, 0.33 to 1.34), and intermediate dose unfractionated heparin (0.71, 0.43 to 1.19) were most likely to reduce symptomatic venous thromboembolism (very low to low quality evidence). Intermediate dose unfractionated heparin (2.63, 1.00 to 6.21) and direct oral anticoagulants (2.31, 0.82 to 6.47) were most likely to increase major bleeding (low to moderate quality evidence). No conclusive differences were noted between interventions regarding serious adverse events (very low to low quality evidence). When compared with no intervention instead of placebo, all active interventions did more favourably with regard to risk of venous thromboembolism and mortality, and less favourably with regard to risk of major bleeding. The results were robust in prespecified sensitivity and subgroup analyses.

CONCLUSIONS

Low-molecular-weight heparin in an intermediate dose appears to confer the best balance of benefits and harms for prevention of venous thromboembolism. Unfractionated heparin, in particular the intermediate dose, and direct oral anticoagulants had the least favourable profile. A systematic discrepancy was noted in intervention effects that depended on whether placebo or no intervention was the reference treatment. Main limitations of this study include the quality of the evidence, which was generally low to moderate due to imprecision and within-study bias, and statistical inconsistency, which was addressed post hoc.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42020173088.

Anticoagulants for acute ischaemic stroke

BACKGROUND

Stroke is the third leading cause of early death worldwide. Most ischaemic strokes are caused by a blood clot blocking an artery in the brain. Patient outcomes might be improved if they are offered anticoagulants that reduce their risk of developing new blood clots and do not increase the risk of bleeding. This is an update of a Cochrane Review first published in 1995, with updates in 2004, 2008, and 2015.

OBJECTIVES

To assess the effectiveness and safety of early anticoagulation (within the first 14 days of onset) for people with acute presumed or confirmed ischaemic stroke. Our hypotheses were that, compared with a policy of avoiding their use, early anticoagulation would be associated with: • reduced risk of death or dependence in activities of daily living a few months after stroke onset; • reduced risk of early recurrent ischaemic stroke; • increased risk of symptomatic intracranial and extracranial haemorrhage; and • reduced risk of deep vein thrombosis and pulmonary embolism.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (August 2021); the Cochrane Database of Systematic Reviews (CDSR); the Cochrane Central Register of Controlled Trials (CENTRAL; 2021, Issue 7), in the Cochrane Library (searched 5 August 2021); MEDLINE (2014 to 5 August 2021); and Embase (2014 to 5 August 2021). In addition, we searched ongoing trials registries and reference lists of relevant papers. For previous versions of this review, we searched the register of the Antithrombotic Trialists' (ATT) Collaboration, consulted MedStrategy (1995), and contacted relevant drug companies.

SELECTION CRITERIA

Randomised trials comparing early anticoagulant therapy (started within two weeks of stroke onset) with control in people with acute presumed or confirmed ischaemic stroke.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion, assessed trial quality, and extracted data. We assessed the overall certainty of the evidence for each outcome using RoB1 and GRADE methods.

MAIN RESULTS

We included 28 trials involving 24,025 participants. Quality of the trials varied considerably. We considered some studies to be at unclear or high risk of selection, performance, detection, attrition, or reporting bias. Anticoagulants tested were standard unfractionated heparin, low-molecular-weight heparins, heparinoids, oral anticoagulants, and thrombin inhibitors. Over 90% of the evidence is related to effects of anticoagulant therapy initiated within the first 48 hours of onset. No evidence suggests that early anticoagulation reduced the odds of death or dependence at the end of follow-up (odds ratio (OR) 0.98, 95% confidence interval (CI) 0.92 to 1.03; 12 RCTs, 22,428 participants; high-certainty evidence). Similarly, we found no evidence suggesting that anticoagulant therapy started within the first 14 days of stroke onset reduced the odds of death from all causes (OR 0.99, 95% CI 0.90 to 1.09; 22 RCTs, 22,602 participants; low-certainty evidence) during the treatment period. Although early anticoagulant therapy was associated with fewer recurrent ischaemic strokes (OR 0.75, 95% CI 0.65 to 0.88; 12 RCTs, 21,665 participants; moderate-certainty evidence), it was also associated with an increase in symptomatic intracranial haemorrhage (OR 2.47; 95% CI 1.90 to 3.21; 20 RCTs, 23,221 participants; moderate-certainty evidence). Similarly, early anticoagulation reduced the frequency of symptomatic pulmonary emboli (OR 0.60, 95% CI 0.44 to 0.81; 14 RCTs, 22,544 participants; high-certainty evidence), but this benefit was offset by an increase in extracranial haemorrhage (OR 2.99, 95% CI 2.24 to 3.99; 18 RCTs, 22,255 participants; moderate-certainty evidence).

AUTHORS' CONCLUSIONS

Since the last version of this review, four new relevant studies have been published, and conclusions remain consistent. People who have early anticoagulant therapy after acute ischaemic stroke do not demonstrate any net short- or long-term benefit. Treatment with anticoagulants reduced recurrent stroke, deep vein thrombosis, and pulmonary embolism but increased bleeding risk. Data do not support the routine use of any of the currently available anticoagulants for acute ischaemic stroke.

Real-World Comparative Effectiveness and Cost Comparison of Thromboprophylactic Use of Enoxaparin versus Unfractionated Heparin in 376,858 Medically Ill Hospitalized US Patients

BACKGROUND

Venous thromboembolism (VTE) is a serious complication in medically ill inpatients. Enoxaparin or unfractionated heparin (UFH) thromboprophylaxis has been shown to reduce VTE in clinical trials; however, comparative effectiveness and differences in hospital costs are unknown in US hospital practice.

OBJECTIVE

This study compared clinical and economic outcomes between enoxaparin and UFH thromboprophylaxis in medically ill inpatients.

METHODS

A retrospective cohort study was conducted using the Premier Healthcare Database between 1 January 2010 and 30 September 2016. Inpatients aged ≥ 18 years with a ≥ 6-day hospital stay for serious medical conditions were included. Two patient groups receiving thromboprophylaxis were identified during hospitalization: one receiving enoxaparin and other receiving UFH. Regression models were constructed to compare VTE events, in-hospital mortality, pulmonary embolism (PE)-related mortality, major bleeding, and total hospital costs during both the index hospitalization and the 90-day readmission period between the two groups.

RESULTS

A total of 242,474 and 134,384 inpatients received enoxaparin or UFH for thromboprophylaxis, respectively. Compared with UFH prophylaxis, enoxaparin was significantly associated with 15%, 9%, 33%, and 41% reduced odds of VTE, in-hospital mortality, PE-related mortality, and major bleeding, respectively, during index hospitalization, and 10% and 19% reduced odds of VTE and bleeding, respectively, during the readmission period. Mean total hospital costs were significantly lower in patients receiving enoxaparin prophylaxis than in those given UFH.

CONCLUSIONS

Thromboprophylaxis with enoxaparin was associated with significantly reduced in-hospital VTE events, death, and major bleeding and lower hospital costs compared with UFH in hospitalized medically ill patients.

Enoxaparin is associated with lower rates of mortality than unfractionated Heparin in hospitalized COVID-19 patients

BACKGROUND

Coagulopathies are a major class among COVID-19 associated complications. Although anticoagulants such as unfractionated Heparin and Enoxaparin are both being used for therapeutic mitigation of COVID associated coagulopathy (CAC), differences in their clinical outcomes remain to be investigated.

METHODS

We analyzed records of 1,113 patients in the Mayo Clinic Electronic Health Record (EHR) database who were admitted to the hospital for COVID-19 between April 4, 2020 and August 31, 2020, including 19 different Mayo Clinic sites in Arizona, Florida, Minnesota, and Wisconsin. Among this patient population, we compared cohorts of patients who received different types of anticoagulants, including 441 patients who received unfractionated Heparin and 166 patients who received Enoxaparin. Clinical outcomes at 28 days were compared, and propensity score matching was used to control for potential confounding variables including: demographics, comorbidities, ICU status, chronic kidney disease stage, and oxygenation status. Patients with a history of acute kidney injury and patients who received multiple types of anticoagulants were excluded from the study.

FINDINGS

We find that COVID-19 patients administered unfractionated Heparin but not Enoxaparin have higher rates of 28-day mortality (risk ratio: 4.3; 95% Confidence Interval [C.I.].: [1.8, 10.2]; p-value: 8.5e-4, Benjamini Hochberg [BH] adjusted p-value: 2.1e-3), after controlling for potential confounding factors.

INTERPRETATION

This study emphasizes the need for mechanistically investigating differential modulation of the COVID-associated coagulation cascades by Enoxaparin versus unfractionated Heparin.

FUNDING

This work was supported by Nference, inc.

Enoxaparin prevents CXCL16/ADAM10-mediated cisplatin renal toxicity: Role of the coagulation system and the transcriptional factor NF-κB

BACKGROUND AND AIMS

C-X-C ligand 16 (CXCL16) is an exceptional chemokine that is expressed as transmembrane and soluble forms. Our aim is to shed lights on the role of CXCL16/ADAM10 (a disintegrin and metalloproteinase) in cisplatin (CP)-induced renal toxicity as well as possible protective effect of enoxaparin.

MAIN METHODS

Male albino mice were injected with CP (30 mg/kg, i.p.) in the presence or absence of enoxaparin (ENOX) (5 mg/kg, i.p.). Renal toxicity markers, serum level of cystatin-c, complete blood count (CBC), prothrombin time (Pt) and tissue expression of CXCL16, ADAM10, cluster of differentiation 3 (CD3), fibrinogen, tissue factor (TF), nuclear factor-κB (NF-κB) and tumour necrosis factor α (TNF-α) were measured. Besides, serum CXCL16 and histopathology were also analyzed.

KEY FINDINGS

CP increased renal toxicity markers, renal expression of CXCL16/ADAM10, fibrinogen, TF and CD3 tissue expression in a time-dependent manner, and elevated serum cystatin-c, CXCL16 and tissue TNF-α, NF-κB. Alternatively, ENOX restored the deteriorated parameters and reduced tissue level of NF-κB.

SIGNIFICANCE

This report, for the first time, showed that soluble CXCL16 resulting from ADAM10 cleavage may recruit T-cells to the renal glomeruli and tubules in CP toxicity. Furthermore, TF and fibrin, have similar expression and location pattern like CXCL16 and ADAM10 suggesting their possible interrelation. ENOX successfully restored the deteriorated parameters suggesting it may be an effective nephroprotective adjuvant therapy.

Coagulopathy, Venous Thromboembolism, and Anticoagulation in Patients with COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) has led to a worldwide pandemic, and patients with the infection are referred to as having COVID‐19. Although COVID‐19 is commonly considered a respiratory disease, there is clearly a thrombotic potential that was not expected. The pathophysiology of the disease and subsequent coagulopathy produce an inflammatory, hypercoagulable, and hypofibrinolytic state. Several observational studies have demonstrated surprisingly high rates of venous thromboembolism (VTE) in both general ward and intensive care patients with COVID‐19. Many of these observational studies demonstrate high rates of VTE despite patients being on standard, or even higher intensity, pharmacologic VTE prophylaxis. Fibrinolytic therapy has also been used in patients with acute respiratory distress syndrome. Unfortunately, high quality randomized controlled trials are lacking. A literature search was performed to provide the most up‐to‐date information on the pathophysiology, coagulopathy, risk of VTE, and prevention and treatment of VTE in patients with COVID‐19. These topics are reviewed in detail, along with practical issues of anticoagulant selection and duration. Although many international organizations have produced guidelines or consensus statements, they do not all cover the same issues regarding anticoagulant therapy for patients with COVID‐19, and they do not all agree. These statements and the most recent literature are combined into a list of clinical considerations that clinicians can use for the prevention and treatment of VTE in patients with COVID‐19.

American Society of Hematology 2018 guidelines for management of venous thromboembolism: prophylaxis for hospitalized and nonhospitalized medical patients

BACKGROUND

Venous thromboembolism (VTE) is the third most common vascular disease. Medical inpatients, long-term care residents, persons with minor injuries, and long-distance travelers are at increased risk.

OBJECTIVE

These evidence-based guidelines from the American Society of Hematology (ASH) intend to support patients, clinicians, and others in decisions about preventing VTE in these groups.

METHODS

ASH formed a multidisciplinary guideline panel balanced to minimize potential bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline-development process, including updating or performing systematic evidence reviews. The panel prioritized clinical questions and outcomes according to their importance for clinicians and adult patients. The Grading of Recommendations Assessment, Development and Evaluation approach was used to assess evidence and make recommendations, which were subject to public comment.

RESULTS

The panel agreed on 19 recommendations for acutely ill and critically ill medical inpatients, people in long-term care facilities, outpatients with minor injuries, and long-distance travelers.

CONCLUSIONS

Strong recommendations included provision of pharmacological VTE prophylaxis in acutely or critically ill inpatients at acceptable bleeding risk, use of mechanical prophylaxis when bleeding risk is unacceptable, against the use of direct oral anticoagulants during hospitalization, and against extending pharmacological prophylaxis after hospital discharge. Conditional recommendations included not to use VTE prophylaxis routinely in long-term care patients or outpatients with minor VTE risk factors. The panel conditionally recommended use of graduated compression stockings or low-molecular-weight heparin in long-distance travelers only if they are at high risk for VTE.

Low-molecular-weight heparins or heparinoids versus standard unfractionated heparin for acute ischaemic stroke

BACKGROUND

Low-molecular-weight heparins (LMWHs) and heparinoids are anticoagulants that may have more powerful antithrombotic effects than standard unfractionated heparin (UFH) but a lower risk of bleeding complications. This is an update of the original Cochrane Review of these agents, first published in 2001 and last updated in 2008.

OBJECTIVES

To determine whether antithrombotic therapy with LMWHs or heparinoids is associated with a reduction in the proportion of people who are dead or dependent for activities in daily living compared with UFH.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (last searched February 2017), the Cochrane Central Register of Controlled Trials (CENTRAL: the Cochrane Library Issue 1, 2017), MEDLINE (1966 to February 2017), and Embase (1980 to February 2017). We also searched trials registers to February 2017: ClinicalTrials.gov, EU Clinical Trials Register, Stroke Trials Registry, ISRCTN Registry and the World Health Organization (WHO) International Clinical Trials Registry Platform.

SELECTION CRITERIA

Unconfounded randomised trials comparing LMWH or heparinoids with standard UFH in people with acute ischaemic stroke, in which participants were recruited within 14 days of stroke onset.

DATA COLLECTION AND ANALYSIS

Two review authors independently chose studies for inclusion, assessed risk of bias and trial quality, extracted and analysed the data. Differences were resolved by discussion.

MAIN RESULTS

We included nine trials involving 3137 participants. We did not identify any new trials for inclusion in this updated review. None of the studies reported data on the primary outcome in sufficient detail to enable analysis for the review. Overall, there was a moderate risk of bias in the included studies. Compared with UFH, there was no evidence of an effect of LMWH or heparinoids on death from all causes during the treatment period (96/1616 allocated LMWH/heparinoid versus 78/1486 allocated UFH; odds ratio (OR) 1.06, 95% CI 0.78 to 1.47; 8 trials, 3102 participants, low quality evidence). LMWH or heparinoid were associated with a significant reduction in deep vein thrombosis (DVT) compared with UFH (OR 0.55, 95% CI 0.44 to 0.70, 7 trials, 2585 participants, low quality evidence). However, the number of the major clinical events such as pulmonary embolism (PE) and intracranial haemorrhage was too small to provide a reliable estimate of the effects.

AUTHORS' CONCLUSIONS

Treatment with a LMWH or heparinoid after acute ischaemic stroke appears to decrease the occurrence of DVT compared with standard UFH, but there are too few data to provide reliable information on their effects on other important outcomes, including functional outcome, death and intracranial haemorrhage.

Thromboprophylaxis Failure in the Adult Medical Inpatient

Venous thromboembolism (VTE), a leading cause of morbidity and mortality among hospitalized patients, is often due to prophylaxis failure rather than omission, but few studies have identified the risk factors for failure. Risk factors for thromboprophylaxis failure include personal or family history of VTE, use of vasopressors or inotropes, increased body mass index, cranial surgery, intensive care patient, leukocytosis, indwelling central venous catheter and admission from a long-term care facility. Identifying patients at risk for thromboprophylaxis failure should prompt close observation during hospitalization for signs of VTE, close observation after discharge and potentially more aggressive prophylaxis strategies, although no specific guidelines exist for medical patients at this time.

European Stroke Organisation (ESO) guidelines for prophylaxis for venous thromboembolism in immobile patients with acute ischaemic stroke

Background

Venous thromboembolism (VTE) including deep vein thrombosis (DVT) and pulmonary embolism is a frequent complication in immobile patients with acute ischemic stroke. This guideline document presents the European Stroke Organisation guidelines for the prophylaxis of VTE in immobile patients with acute ischaemic stroke. Guidelines for haemorrhagic stroke have already been published.

Methods

A multidisciplinary group identified related questions and developed its recommendations based on evidence from randomised controlled trials using the Grading of Recommendations Assessment, Development, and Evaluation approach. This guideline document was reviewed within the European Stroke Organisation and externally and was approved by the European Stroke Organisation Guidelines Committee and the European Stroke Organisation Executive Committee.

Results

We found mainly moderate quality evidence comprising randomised controlled trials and systematic reviews evaluating graduated compression stockings (GCS), intermittent pneumatic compression (IPC) and prophylactic anticoagulation with unfractionated (UFH) and low molecular weight heparins (LMWH) and heparinoids, but no randomised trials evaluating neuromuscular electrical stimulation (NES). We recommend that clinicians should use IPC in immobile patients, but that they should not use GCS. Prophylactic anticoagulation with UFH (5000U ×2, or ×3 daily) or LMWH or heparinoid should be considered in immobile patients with ischaemic stroke in whom the benefits of reducing the risk of VTE is high enough to offset the increased risks of intracranial and extracranial bleeding associated with their use. Where a judgement has been made that prophylactic anticoagulation is indicated LMWH or heparinoid should be considered instead of UFH because of its greater reduction in risk of DVT, the greater convenience, reduced staff costs and patient comfort associated single vs. multiple daily injections but these advantages should be weighed against the higher risk of extracranial bleeding, higher drug costs and risks in elderly patients with poor renal function associated with LMWH and heparinoids.

Conclusions

IPC, UFH or LMWH and heparinoids can reduce the risk of VTE in immobile patients with acute ischaemic stroke but further research is required to test whether NES is effective. The strongest evidence is for IPC. Better methods are needed to help stratify patients in the first few weeks after stroke onset, by their risk of VTE and their risk of bleeding on anticoagulants.

Evidence-based guidelines for the management of large hemispheric infarction : a statement for health care professionals from the Neurocritical Care Society and the German Society for Neuro-intensive Care and Emergency Medicine

Large hemispheric infarction (LHI), also known as malignant middle cerebral infarction, is a devastating disease associated with significant disability and mortality. Clinicians and family members are often faced with a paucity of high quality clinical data as they attempt to determine the most appropriate course of treatment for patients with LHI, and current stroke guidelines do not provide a detailed approach regarding the day-to-day management of these complicated patients. To address this need, the Neurocritical Care Society organized an international multidisciplinary consensus conference on the critical care management of LHI. Experts from neurocritical care, neurosurgery, neurology, interventional neuroradiology, and neuroanesthesiology from Europe and North America were recruited based on their publications and expertise. The panel devised a series of clinical questions related to LHI, and assessed the quality of data related to these questions using the Grading of Recommendation Assessment, Development and Evaluation guideline system. They then developed recommendations (denoted as strong or weak) based on the quality of the evidence, as well as the balance of benefits and harms of the studied interventions, the values and preferences of patients, and resource considerations.

Heparin and related drugs for venous thromboembolism prophylaxis: subcutaneous or intravenous continuous infusion?

In this article, the most evidenced approaches of unfractionated heparin administration for prevention of venous thromboembolism in medical and surgical hospitalized patients will be reviewed. Present data were collected by searching Scopus, PubMed, MEDLINE, Science direct, Clinical trials and Cochrane database systematic reviews. Subcutaneous low doses of unfractionated heparin (10000–15000 IU) in two or three divided doses per day are commonly administrated for venous thromboembolism prevention in different medical and surgical populations. In some populations such as obese surgical and critically ill patients, due to altered pharmacokinetics behavior of unfractionated heparin, continuous intravenous infusion of the low doses of unfractionated heparin has been proposed.

Prevention of Venous Thromboembolism After Stroke

Venous thromboembolism (VTE) is a common complication following acute ischemic and hemorrhagic stroke. Pulmonary embolism (PE), the most serious consequence of deep vein thrombosis (DVT), can result in significant morbidity and death. Patients with stroke are at particular risk because of limb paralysis, prolonged bed rest, and increased prothrombotic activity. Preventive measures should be taken at all levels of care and can include mechanical calf compression, antiplatelet agents, and the use of anticoagulants such as heparin and low molecular weight heparin. Prevention of VTE should be incorporated into all stroke care pathways.

Medical Management of Patients with an Acute Stroke: Treatment and Prevention

Stroke is a common and serious disorder and will probably occur with increasing frequency due to an aging of the population. Acute therapies aimed at reversing the effects of acute ischemic stroke are limited to recombinant tissue plasminogen activator administered intravenously within 3 hours of stroke onset. Neuroprotective agents and acute anticoagulation with agents such as heparinoids and heparin are not effective in most cases. Poststroke medical complications such as infection and venous thromboembolism are common but are largely preventable. A variety of medical therapies such as antiplatelet agents, warfarin, statins, and ACE inhibitors can reduce the risk of a recurrent stroke. A key aspect of management for stroke is selection of the proper treatment regimen for each patient.

Trends in Hospital Admission for Stroke in Calgary

Background:

Stroke incidence has fallen since 1950. Recent trends suggest that stroke incidence may be stabilizing or increasing. We investigated time trends in stroke occurrence and in-hospital morbidity and mortality in the Calgary Health Region.

Methods:

All patients admitted to hospitals in the Calgary Health Region between 1994 and 2002 with a primary discharge diagnosis code (ICD-9 or ICD-10) of stroke were included. In-hospital strokes were also included. Stroke type, date of admission, age, gender, discharge disposition (died, discharged) and in-hospital complications (pneumonia, pulmonary embolism, deep venous thrombosis) were recorded. Poisson and simple linear regression was used to model time trends of occurrence by stroke type and age-group and to extrapolate future time trends.

Results:

From 1994 to 2002, 11642 stroke events were observed. Of these, 9879 patients (84.8%) were discharged from hospital, 1763 (15.1%) died in hospital, and 591 (5.1%) developed in-hospital complications from pneumonia, pulmonary embolism or deep venous thrombosis. Both in-hospital mortality and complication rates were highest for hemorrhages. Over the period of study, the rate of stroke admission has remained stable. However, total numbers of stroke admission to hospital have faced a significant increase (p=0.012) due to the combination of increases in intracerebral hemorrhage (p=0.021) and ischemic stroke admissions (p=0.011). Sub-arachnoid hemorrhage rates have declined. In-hospital stroke mortality has experienced an overall decline due to a decrease in deaths from ischemic stroke, intracerebral hemorrhage and sub-arachnoid hemorrhage.

Conclusion:

Although age-adjusted stroke occurrence rates were stable from 1994 to 2002, this is associated with both a sharp increase in the absolute number of stroke admissions and decline in proportional in-hospital mortality. Further research is needed into changes in stroke severity over time to understand the causes of declining in-hospital stroke mortality rates.

Thrombo-prophylaxis in acutely ill medical and critically ill patients

Thrombo-prophylaxis has been shown to reduce the incidence of pulmonary embolism (PE) and mortality in surgical patients. The purpose of this review is to find out the evidence-based clinical practice criteria of deep vein thrombosis (DVT) prophylaxis in acutely ill medical and critically ill patients. English-language randomized controlled trials, systematic reviews, and meta-analysis were included if they provided clinical outcomes and evaluated therapy with low-dose heparin or related agents compared with placebo, no treatment, or other active prophylaxis in the critically ill and medically ill population. For the same, we searched MEDLINE, PUBMED, Cochrane Library, and Google Scholar. In acutely ill medical patients on the basis of meta-analysis by Lederle et al. (40 trials) and LIFENOX study, heparin prophylaxis had no significant effect on mortality. The prophylaxis may have reduced PE in acutely ill medical patients, but led to more bleeding events, thus resulting in no net benefit. In critically ill patients, results of meta-analysis by Alhazzani et al. and PROTECT Trial indicate that any heparin prophylaxis compared with placebo reduces the rate of DVT and PE, but not symptomatic DVT. Major bleeding risk and mortality rates were similar. On the basis of MAGELLAN trial and EINSTEIN program, rivaroxaban offers a single-drug approach to the short-term and continued treatment of venous thrombosis. Aspirin has been used as antiplatelet agent, but when the data from two trials the ASPIRE and WARFASA study were pooled, there was a 32% reduction in the rate of recurrence of venous thrombo-embolism and a 34% reduction in the rate of major vascular events.

Venous thromboembolism in neurologic disease

Patients with neurologic disease are at high risk of venous thromboembolism (VTE) because of relative immobility. They are also at increased risk due to the presence of a hypercoagulable state. Patients with spinal cord injuries, brain tumors, and strokes are at particularly high risk and extra vigilance is needed in these patients. Because VTE is very common in hospitalized neurologic and neurosurgical patients, mechanical thromboprophylaxis is indicated in virtually all patients. Pharmacologic prophylaxis with either subcutaneous heparin or low molecular heparinoids should be given to all high-risk neurologic and neurosurgical patients provided there are no major contraindications. The major concern would be a risk of bleeding but in some patients alternate drugs must be considered given the risk of thrombosis (i.e., in the context of heparin-induced thrombocytopenia). The immediate or long-term treatment of full dose anticoagulation for VTE may not be appropriate in all patients as VTE therapy represents a balance between the risks of bleeding related to anticoagulant therapy versus the risk of recurrent events. An inferior vena cava (IVC) filter is another option in these patients but may not necessarily be the best choice for most neurologic patients. Given the high risk of VTE in patients with neurologic diseases, early recognition by clinicians of the signs and symptoms of VTE is essential.

Prevention of venous thromboembolism in patients with hemorrhagic stroke

Deep venous thrombosis (DVT) and pulmonary embolism (PE) are part of the spectrum of venous thromboembolism (VTE). It is one of the most frequent medical complications in stroke patients. The risk of VTE is even higher after hemorrhagic stroke. This article reviews various screening methods, diagnostic techniques, and pharmacologic as well as nonpharmacologic means of preventing VTE after hemorrhagic stroke.

Rate of deep-vein thrombosis and pulmonary embolism during the care continuum in patients with acute ischemic stroke in the United States

BACKGROUND

Deep-vein thrombosis (DVT) and pulmonary embolism (PE) are frequent and life-threatening complications of ischemic stroke. We evaluated rates of symptomatic DVT/PE, and of in-hospital and post-discharge thromboprophylaxis in patients with acute ischemic stroke (AIS).

METHODS

In a retrospective US database analysis, data were extracted from the Premier Perspective™-i3 Pharma Informatics linked database for patients aged ≥18 years who were hospitalized for ischemic stroke from January 2005 to November 2007, and who had ≥6 months' continuous plan enrollment prior to index hospitalization. Patients discharged to an acute-care facility or with atrial fibrillation were excluded. Prophylaxis was evaluated during index hospitalization and for 14 days' post-discharge. DVT/PE rates were calculated during index hospitalization and up to 30 days post-discharge.

RESULTS

A total of 1524 patients were included; 46.1% received pharmacological and/or mechanical prophylaxis in-hospital (28.3%, 11.4% and 12.3% received unfractionated heparin, enoxaparin and mechanical prophylaxis, respectively). 6.4% of patients received outpatient pharmacological prophylaxis; warfarin was most frequently prescribed (5.9%). Total mean ± standard deviation length of index hospitalization was 3.0 ± 2.5 days. Mean prophylaxis duration in all patients was 0.9 ± 1.5 days in-hospital and 1.7 ± 6.9 days post-discharge. Symptomatic DVT/PE occurred in 25 patients overall (1.64%), with an inpatient rate of 0.98% and an outpatient rate of 0.66%.

CONCLUSIONS

Approximately 1% of patients with AIS experienced symptomatic in-hospital and/or post-discharge DVT/PE. Although 46% received prophylaxis in-hospital, only 6% received prophylaxis in the outpatient setting. This highlights the need for sustained thromboprophylaxis prescribing across the continuum of care.

Guidelines for the early management of patients with acute ischemic stroke: a guideline for healthcare professionals from the American Heart Association/American Stroke Association

BACKGROUND AND PURPOSE

The authors present an overview of the current evidence and management recommendations for evaluation and treatment of adults with acute ischemic stroke. The intended audiences are prehospital care providers, physicians, allied health professionals, and hospital administrators responsible for the care of acute ischemic stroke patients within the first 48 hours from stroke onset. These guidelines supersede the prior 2007 guidelines and 2009 updates.

METHODS

Members of the writing committee were appointed by the American Stroke Association Stroke Council's Scientific Statement Oversight Committee, representing various areas of medical expertise. Strict adherence to the American Heart Association conflict of interest policy was maintained throughout the consensus process. Panel members were assigned topics relevant to their areas of expertise, reviewed the stroke literature with emphasis on publications since the prior guidelines, and drafted recommendations in accordance with the American Heart Association Stroke Council's Level of Evidence grading algorithm.

RESULTS

The goal of these guidelines is to limit the morbidity and mortality associated with stroke. The guidelines support the overarching concept of stroke systems of care and detail aspects of stroke care from patient recognition; emergency medical services activation, transport, and triage; through the initial hours in the emergency department and stroke unit. The guideline discusses early stroke evaluation and general medical care, as well as ischemic stroke, specific interventions such as reperfusion strategies, and general physiological optimization for cerebral resuscitation.

CONCLUSIONS

Because many of the recommendations are based on limited data, additional research on treatment of acute ischemic stroke remains urgently needed.

Venous thromboembolism in the Get With The Guidelines-Stroke acute ischemic stroke population: incidence and patterns of prophylaxis

BACKGROUND

Venous thromboembolism (VTE), which includes deep vein thrombosis (DVT) and pulmonary embolus (PE), represents a serious complication in hospitalized ischemic stroke patients. This study examines the incidence of VTE and the patterns of VTE prophylaxis in acute ischemic stroke patients deemed appropriate for VTE prophylaxis (nonambulatory) in the Get With The Guidelines-Stroke (GWTG-S) study.

METHODS

We analyzed data from 149,916 patients who were admitted with acute ischemic stroke and enrolled in GWTG-S from 1259 U.S. hospitals. Patient variables and site characteristics were analyzed in relation to reported administration of VTE prophylaxis.

RESULTS

The overall rate of VTE prophylaxis in the analysis cohort was 93% (139,476/149,916). The median site prophylaxis rate was 95%, and prophylaxis rates ranged from 17% (1 site) to 100% (101 sites). Factors associated with increased likelihood of VTE prophylaxis in the multivariable model included history of atrial fibrillation/flutter, receipt of intravenous or intra-arterial tissue plasminogen activator, and admission to an academic hospital. Increasing age, black race, and a history of peripheral vascular disease, diabetes, or stroke were associated with lower likelihood of prophylaxis. Patients receiving care in the Midwest were less likely to receive prophylaxis compared to other regions.

CONCLUSIONS

Despite a high overall rate of VTE prophylaxis, VTE was found to occur in approximately 3% of GWTG-S patients. Reported rates of VTE prophylaxis differed among hospitals by region and hospital type, and among patients by age, race, and medical comorbidities.

Economic impact of enoxaparin versus unfractionated heparin for venous thromboembolism prophylaxis in patients with acute ischemic stroke: a hospital perspective of the PREVAIL trial

BACKGROUND

The PREVAIL (Prevention of VTE [venous thromboembolism] after acute ischemic stroke with LMWH [low-molecular-weight heparin] and UFH [unfractionated heparin]) study demonstrated a 43% VTE risk reduction with enoxaparin versus UFH in patients with acute ischemic stroke (AIS). A 1% rate of symptomatic intracranial and major extracranial hemorrhage was observed in both groups.

OBJECTIVE

To determine the economic impact, from a hospital perspective, of enoxaparin versus UFH for VTE prophylaxis after AIS.

DESIGN

A decision-analytic model was constructed and hospital-based costs analyzed using clinical information from PREVAIL. Total hospital costs were calculated based on mean costs in the Premier™ database and from wholesalers acquisition data. Costs were also compared in patients with severe stroke (National Institutes of Health Stroke Scale [NIHSS] score ≥14) and less severe stroke (NIHSS score <14).

RESULTS

The average cost per patient due to VTE or bleeding events was lower with enoxaparin versus UFH ($422 vs $662, respectively; net savings $240). The average anticoagulant cost, including drug-administration cost per patient, was lower with UFH versus enoxaparin ($259 vs $360, respectively; net savings $101). However, when both clinical events and drug-acquisition costs were considered, the total hospital cost was lower with enoxaparin versus UFH ($782 vs $922, respectively; savings $140). Hospital cost-savings were greatest ($287) in patients with NIHSS scores ≥14.

CONCLUSIONS

The higher drug cost of enoxaparin was offset by the reduction in clinical events as compared to the use of UFH for VTE prophylaxis after an AIS, particularly in patients with severe stroke.

Enoxaparin in cardiovascular disease: how to improve effectiveness and safety?

The review analyses the specifics of enoxaparin therapy in the most prevalent cardiovascular diseases, such as acute coronary syndrome, venous thromboembolism, and atrial fibrillation. The decision strategy is presented for difficult and non-standard clinical situations (renal dysfunction, elderly age, heparin medication change, or abnormal body weight), when the optimal balance between effectiveness and safety requires modifying the standard treatment protocols.

Prevention of Deep Vein Thrombosis and Pulmonary Embolism in Patients With Stroke

Venous thromboembolism (VTE), encompassing deep venous thrombosis and pulmonary embolism, is a potentially fatal but preventable complication of stroke. Reported rates of VTE after stroke have decreased over the last four decades, possibly due to the implementation of stroke units, early mobilization and hydration, and increased early use of antiplatelets. Additional means of thromboprophylaxis in stroke include mechanical methods (ie, compression stockings) to prevent venous stasis and medical therapy including antiplatelets, heparins, and heparinoids. Risk of VTE must be balanced by potential risk of hemorrhagic complications from pharmacotherapy. Unfractionated heparin, low-molecular-weight heparin (LMWH), and danaparoid are acceptable options for chemoprophylaxis though none have shown superior efficacy for VTE prevention without an associated increase in major hemorrhage. The efficacy and timing of pharmacological thromboprophylaxis in hemorrhagic stroke are not well defined. Graduated compression stockings are associated with an increased rate of adverse events and are not recommended and intermittent pneumatic compression stockings require further investigation.

Differentiation of parenteral anticoagulants in the prevention and treatment of venous thromboembolism

BACKGROUND

The prevention of venous thromboembolism has been identified as a leading priority in hospital safety. Recommended parenteral anticoagulant agents with different indications for the prevention and treatment of venous thromboembolism include unfractionated heparin, low-molecular-weight heparins and fondaparinux. Prescribing decisions in venous thromboembolism management may seem complex due to the large range of clinical indications and patient types, and the range of anticoagulants available.

METHODS

MEDLINE and EMBASE databases were searched to identify relevant original articles.

RESULTS

Low-molecular-weight heparins have nearly replaced unfractionated heparin as the gold standard antithrombotic agent. Low-molecular-weight heparins currently available in the US are enoxaparin, dalteparin, and tinzaparin. Each low-molecular-weight heparin is a distinct pharmacological entity with different licensed indications and available clinical evidence. Enoxaparin is the only low-molecular-weight heparin that is licensed for both venous thromboembolism prophylaxis and treatment. Enoxaparin also has the largest body of clinical evidence supporting its use across the spectrum of venous thromboembolism management and has been used as the reference standard comparator anticoagulant in trials of new anticoagulants. As well as novel oral anticoagulant agents, biosimilar and/or generic low-molecular-weight heparins are now commercially available. Despite similar anticoagulant properties, studies report differences between the branded and biosimilar and/or generic agents and further clinical studies are required to support the use of biosimilar low-molecular-weight heparins. The newer parenteral anticoagulant, fondaparinux, is now also licensed for venous thromboembolism prophylaxis in surgical patients and the treatment of acute deep-vein thrombosis; clinical experience with this anticoagulant is expanding.

CONCLUSIONS

Parenteral anticoagulants should be prescribed in accordance with recommended dose regimens for each clinical indication, based on the available clinical evidence for each agent to assure optimal safety and efficacy.

Individual patient data meta-analysis of enoxaparin vs. unfractionated heparin for venous thromboembolism prevention in medical patients

BACKGROUND

Unfractionated heparin (UFH) and low-molecular-weight heparin (LMWH) are both recommended for venous thromboembolism (VTE) prophylaxis in hospitalized medical patients.

OBJECTIVE

To perform an individual patient data meta-analysis to evaluate the relative efficacy and safety of the LMWH enoxaparin and UFH in preventing VTE in hospitalized medical patients.

METHODS

Randomized clinical trials comparing subcutaneous enoxaparin (4000 IU once-daily) and UFH (5000 IU subcutaneous two- or three-times daily) for VTE prevention were identified by a systematic search. Individual patient data were obtained from each eligible trial.

RESULTS

Overall, four trials were eligible, including 3600 patients randomized to receive enoxaparin (n = 1799) or UFH (n = 1801). Median patient age was 71 years, and 49.3% were female. Compared with UFH, enoxaparin was associated with risk reductions of 37% for total VTE [relative risk (RR) 0.63, 95% confidence interval (CI) 0.51-0.77] and 62% for symptomatic VTE (RR 0.38, 95% CI 0.17-0.85) at day 15. RR for total VTE in stroke and non-stroke patients was 0.59 (95% CI 0.47-0.74) and 0.87 (95% CI 0.51-1.50), respectively. Major bleeding rates were consistently low and similar between treatment groups at day 15 (RR 1.13, 95% CI 0.53-2.44). There was a trend towards reduced risk for mortality in patients receiving enoxaparin (RR 0.83, 95% CI 0.64-1.08), compared with UFH.

CONCLUSIONS

Enoxaparin significantly reduces VTE in hospitalized medical patients, compared with UFH, without increasing the risk for major bleeding, and was associated with a trend towards reduced all-cause mortality.

Venous Thromboembolism Prophylaxis following Acute Ischemic Stroke: A Retrospective Comparison of Unfractionated Heparin, Enoxaparin, and Fondaparinux

Purpose

The objective of this study was to retrospectively review the efficacy and safety of unfractionated heparin (UFH), enoxaparin, and fondaparinux for venous thromboembolism (VTE) prevention following acute ischemic stroke.

Methods

A retrospective chart review was conducted of VTE and major bleeding event rates in patients receiving UFH, enoxaparin, or fondaparinux for VTE prophylaxis following ischemic stroke. This review included charts from an 18-month period at all facilities in the Lehigh Valley Health Network. A total of 889 patients were evaluated.

Results

There was no significant difference between the 3 anticoagulants for the primary outcome of VTE with an incidence of 2.5% (n=9) for UFH, 1.2% (n=3) for enoxaparin, and 0.4% (n=1) for fondaparinux ( P = .065). However, the incidence of major bleeding events was significantly different with an occurrence of 6.2% (n=22) for UFH, 3.2% (n=8) for enoxaparin, and 0.7% (n=2) for fondaparinux ( P = .001). A comparison of the individual agents showed that UFH had a significantly higher rate of major bleeding events when compared to fondaparinux ( P = .003).

Conclusions

In this study population, UFH was observed to increase the risk of major bleeding events in ischemic stroke patients receiving subsequent VTE prophylaxis. Additionally, the possibility of using fondaparinux for VTE prophylaxis in ischemic stroke patients appears to provide at least comparable safety and efficacy compared to UFH and enoxaparin. However, more studies are needed to determine the ideal anticoagulant and timing of prophylaxis in patients following ischemic stroke.

Economic impact of enoxaparin after acute ischemic stroke based on PREVAIL

The efficacy and safety of low-molecular-weight heparins (LMWHs) versus unfractionated heparin (UFH) has been demonstrated for the prevention of venous thromboembolism (VTE) after acute ischemic stroke. Few data exist regarding the economic impact of LMWHs versus UFH in this population. A decision-analytic model was constructed using clinical information from the Prevention of VTE after Acute Ischemic stroke with LMWH Enoxaparin (PREVAIL) study, and drug costs and mean Centers for Medicare & Medicaid Services event costs. When considering the total cost of events and drugs, enoxaparin was associated with cost-savings of $895 per patient compared with UFH ($2018 vs $2913). Findings were retained within the univariate and multivariate analyses. From a payer perspective, enoxaparin was cost-effective compared with UFH in patients with acute ischemic stroke. The difference was driven by the lower clinical event rates with enoxaparin. Use of enoxaparin may help to reduce the clinical and economic burden of VTE.

The importance of appropriate prophylaxis for the prevention of venous thromboembolism in at-risk medical patients

BACKGROUND

Venous thromboembolism (VTE), which encompasses both deep-vein thrombosis and pulmonary embolism, is a significant healthcare problem, leading to considerable morbidity, mortality and resource utilisation.

AIMS

This review discusses the adherence to VTE guideline recommendations and the available clinical evidence on the appropriate type, dose and duration of VTE prophylaxis.

METHODS

A literature survey was conducted using Pub Med and EMBASE to identify publications related to appropriate thromboprophylaxis in medically ill patients at risk of VTE.

RESULTS

Despite evidence from clinical trials and national guidelines, VTE prophylaxis in medically ill patients remains underutilised. The use of unfractionated heparin three-times-daily, low-molecular-weight heparin once-daily and fondaparinux once-daily has demonstrated effectiveness in clinical trials of medically ill patients. However, controversy exists about the use of unfractionated heparin twice-daily, and fondaparinux has not yet received US Food and Drug Administration approval for VTE prophylaxis in medically ill patients.

CONCLUSION

It is important for clinicians to have an understanding of the evidence-based literature when selecting an appropriate drug, at the appropriate dose, for the appropriate duration for VTE prophylaxis in medically ill patients. VTE prophylaxis in medically ill patients is cost-effective, and drugs that are expensive may still be cost-effective when considering improved efficacy and/or safety. Recently, the underutilisation of VTE prophylaxis has led to the involvement of government and other regulatory agencies in an attempt to increase appropriate VTE prophylaxis in US hospitals and improve the clinical and economic outcomes in medical patients at risk of VTE.

VTE prophylaxis for the medical patient: where do we stand? - a focus on cancer patients

Acutely ill medical patients are at moderate to high risk of venous thromboembolism (VTE): approximately 10-30% of general medical patients may develop deep-vein thrombosis or pulmonary embolism, and the latter is a leading contributor to deaths in hospital. Medical conditions associated with a high risk of VTE include cardiac disease, cancer, respiratory disease, inflammatory bowel disease, rheumatological and infectious diseases. Pre-disposing risk factors in medical patients include a history of VTE, history of malignancy, complicating infections, increasing age, thrombophilia, prolonged immobility and obesity. Hence active cancer and a history of cancer are both strongly related to VTE in medical (non-surgical) patients. Heparins, both unfractionated (UFH) and low molecular weight (LMWH) and fondaparinux have been shown to be effective agents in prevention of VTE in this setting. However, it has not yet been possible to demonstrate a significant effect on mortality rates in this population. In medical patients, unfractionated heparin has a higher rate of bleeding complications than low molecular weight heparin. Thromboprophylaxis has been shown to be effective in medical patients with cancer and may have an effect on cancer outcomes. Thromboprophylaxis in patients receiving chemotherapy remains controversial and requires further investigation. There is no evidence for the use of aspirin, warfarin or mechanical methods. We recommend either low molecular weight heparin or fondaparinux as safe and effective agents in the thromboprophylaxis of medical patients.

Venous thromboembolism prophylaxis with unfractionated heparin in the hospitalized medical patient: the case for thrice daily over twice daily dosing

For venous thromboembolism (VTE) prevention in the hospitalized medical patient, no head-to-head trials have been performed of unfractionated heparin (UFH) 5,000 U subcutaneously thrice (i.e. q8 h or TID) daily versus twice daily (q12 h or BID). Several meta-analyses have been undertaken in attempts to determine whether one regimen may be more beneficial for safety and efficacy. Currently, not all international guidelines include a recommended frequency for UFH. Delineation of this frequency may be helpful to the practicing clinician. Primary studies (with a modified Jadad score of >or=6 to demonstrate a stronger study design) that compared low molecular weight heparin (LMWH) and UFH, and UFH and placebo were evaluated. Meta-analyses evaluating safety and efficacy of LMWH versus UFH, or TID UFH versus BID UFH were also evaluated. Although BID UFH shows some efficacy in one primary study, it is no more beneficial than no prophylaxis in another study. LMWH appears to be more efficacious than BID UFH, but comparable in safety and efficacy to TID UFH. Meta-analytic data demonstrates that BID UFH may have some reduction in deep vein thrombosis. Meta-analytic data also suggests that TID UFH is more efficacious than BID UFH at the cost of more major bleeding. The medical patient with risk factors for the development of VTE appears to be at moderate to high risk. International guidelines for VTE prevention should incorporate a frequency for UFH to guide use. TID UFH is superior in efficacy to BID UFH even when taking into consideration the increased rate of major bleeds. Newly published risk-assessment models may be beneficial in determining which patients would best benefit from BID UFH or TID UFH.

Prophylaxis for venous thrombo-embolism in neurocritical care: a critical appraisal

Venous thrombo-embolism (VTE) is frequently encountered in critically ill neurological and neurosurgical patients admitted to intensive care units. This patient population includes those with brain neoplasm, intracranial hemorrhage, ischemic stroke, subarachnoid hemorrhage, pre- and post-operative patients undergoing neurosurgical procedures and those with traumatic brain injury, and acute spinal cord injury (SCI). There is a wide variability in clinical practice for thromboprophylaxis in these patients, in part due to paucity of data based on randomized clinical trials. Here, we review the current literature on the incidence of VTE in the critically ill neurological and neurosurgical patients as well as appraise available data to support particular practice paradigms for specific subsets of these patients. Data synthesis was conducted via search of Medline, Cochrane databases, and manual review of article bibliographies. Critically ill neurological and neurosurgical patients have higher susceptibility to VTE. Intermittent compression devices with or without anti-thrombotics is generally the method of choice for thromboprophylaxis. Low molecular weight heparin is the method of choice in certain patient subgroups such as those with SCI and ischemic stroke. Inferior vena cava filters may play a role in thromboprophylaxis in selected cases. Without clear guidelines that can be universally applied to this diverse group of patients, prophylaxis for VTE should be tailored to the individual patient with cautious assessment of benefits versus risks. There is a need for higher level evidence to guide VTE prophylaxis in certain subgroups of this patient population.

Prolonged thromboprophylaxis with enoxaparin in early neurological rehabilitation

Prevention of venous thromboembolism (VTE) is essential in neurological patients. Little is known about the optimal duration, efficacy, and safety of prolonged off-label use of low-molecular-weight heparin (LMWH). We enrolled n = 1176 early neurological rehabilitation cases in a retrospective study. In most cases (n = 1151, 97.9%), 4000 anti-Xa (activated coagulation factor X [factor Xa]) units enoxaparin were administered, only 25 received 2000 units for approximately 2 months (mean of 57.5 days). In 969 cases, enoxaparin was administered for more than 2 weeks. Incidence of symptomatic deep vein thrombosis (DVT) and pulmonary embolism (PE) were 0.43% (n = 5) and 1.11% (n = 13), respectively. Hemorrhages during enoxaparin therapy were more frequent. Bleeding occurred in 1.96% (n = 23) of cases, mainly gastrointestinal, urinary tract, and vitreous body bleeding. In short-term (up to 2 weeks) treatment, bleeding and VTE were more frequent than in long-term treatment. Results from this study suggest that prolonged enoxaparin thromboprophylaxis in neurological rehabilitation is safe and effective.

Neurological Outcomes in Patients With Ischemic Stroke Receiving Enoxaparin or Heparin for Venous Thromboembolism Prophylaxis

Background and Purpose— The Prevention of VTE after Acute Ischemic Stroke with LMWH (PREVAIL) study demonstrated that enoxaparin was superior to unfractionated heparin (UFH) in preventing venous thromboembolism in patients with ischemic stroke and was associated with a small but statistically significant increase in extracranial hemorrhage rates. In this PREVAIL subanalysis, we evaluate the long-term neurological outcomes associated with the use of enoxaparin compared with UFH. We also determine predictors of stroke progression.

Methods— Acute ischemic stroke patients aged ≥18 years, who could not walk unassisted, were randomized to receive enoxaparin (40 mg once daily) or UFH (5000 U every 12 hours) for 10 days. Patients were stratified according to baseline stroke severity using the National Institutes of Health Stroke Scale score. End points for this analysis included stroke progression (≥4-point increase in National Institutes of Health Stroke Scale score), neurological outcomes up to 3 months postrandomization (assessed using National Institutes of Health Stroke Scale score and modified Rankin Scale score), and incidence of intracranial hemorrhage.

Results— Stroke progression occurred in 45 of 877 (5.1%) patients in the enoxaparin group and 42 of 872 (4.8%) of those receiving UFH. Similar improvements in National Institutes of Health Stroke Scale and modified Rankin Scale scores were observed in both groups over the 90-day follow-up period. Incidence of intracranial hemorrhage was comparable between groups (20 of 877 [2.3%] and 22 of 872 [2.5%] in enoxaparin and UFH groups, respectively). Baseline National Institutes of Health Stroke Scale score, hyperlipidemia, and Hispanic ethnicity were independent predictors of stroke progression.

Conclusions— The clinical benefits associated with use of enoxaparin for venous thromboembolism prophylaxis in patients with acute ischemic stroke are not associated with poorer long-term neurological outcomes or increased rates of symptomatic intracranial hemorrhage compared with UFH.

Incidence of thrombocytopenia in hospitalized patients with venous thromboembolism

PURPOSE

To determine the incidence of heparin-associated thrombocytopenia in patients receiving prophylaxis or treatment for venous thromboembolism.

METHODS

We assessed the database of the National Hospital Discharge Survey from 1979 through 2005 and complemented this with a meta-analysis of published literature.

RESULT

Among 10,554,000 patients discharged from short-stay hospitals throughout the US with venous thromboembolism during the 27 years of study, secondary thrombocytopenia was coded in 38,000 patients (0.36%). From 1979 through 1992, secondary thrombocytopenia was coded in only 0.15% of hospitalized patients with venous thromboembolism. The frequency increased sharply to 0.54% from 1993 through 2005. Secondary thrombocytopenia was rarely diagnosed among 1,446,000 patients aged <40 years and among 77,000 women who had venous thromboembolism with deliveries. Meta-analysis of published literature showed a higher incidence among patients who received unfractionated heparin (UFH) for prophylaxis than those who received low-molecular-weight heparin (LMWH) for prophylaxis. Treatment resulted in smaller differences of the incidence between UFH and LMWH.

CONCLUSION

Heparin-associated thrombocytopenia is rare among patients aged <40 years and women following delivery. The risk of heparin-associated thrombocytopenia is more duration-related than dose-related, and higher with UFH when used for an extended duration. Our findings and those of the literature suggest that although heparin-associated thrombocytopenia is uncommon, the incidence can be minimized by use of LMWH, particularly if extended prophylaxis or extended treatment is required.

Guidelines for prevention of venous thromboembolism in immobile patients secondary to neurological impairment

BACKGROUND

Venous thromboembolism (VTE) is a major cause of morbidity and mortality in hospitalized patients and 7% of these cases are due to immobility secondary to a neurological impairment. Many guidelines are available to guide clinicians dealing with medical or surgical patients. However, and with the exception of spinal injuries, no guidelines are available to deal with other neurologically impaired patients at risk of VTE.

AIM

Our study aimed at gathering evidence from the literature to enable us to deal with the main controversial issues of VTE prevention. Guidelines will be formulated.

METHOD

A Clinical Standards Group is responsible for the development of clinical guidelines for the Greater Manchester Neurorehabilitation network with services covering a population of around 3 million. The development of VTE prevention guidelines started with the formulation of the main questions, then gathering evidence from the literature to address these questions. Wide consultation then took place. The guidelines were then put before the group for endorsement.

RESULTS

Answers for the main questions such as duration of thromboprophylaxis, TEDS and antiplatelets drugs use were suggested. The resulting document was summarized as a flow chart for use.

CONCLUSION

We feel that the proposed guidelines are a useful tool for clinicians as they reflect the evidence available from the literature at the moment.

Economic and practical aspects of thromboprophylaxis with unfractionated and low-molecular-weight heparins in hospitalized medical patients

Acutely ill medical patients are at significant risk of developing venous thromboembolic (VTE) complications during or after their hospitalization. Venous thromboembolic events, such as proximal deep vein thrombosis (DVT) or pulmonary embolism (PE), place a high and unacceptable burden on health care resources, up to US$1.5 billion annually in the United States. However, the burden of VTE can be reduced by use of appropriate thromboprophylaxis. Prophylaxis of VTE with either a low-dose unfractionated heparin (UFH) or a low-molecular-weight heparin (LMWH) in medical inpatients is effective, well tolerated and cost-effective, compared with no prophylaxis. Low-molecular-weight heparins have a number of practical benefits over UFH, including once-daily subcutaneous injection and the potential to be used in the outpatient setting. These clinical advantages could translate to improved patient adherence to therapy and provide economic benefits, where LMWHs are more cost-effective compared with UFH.