Lack of effect of a low-molecular-weight heparin (nadroparin) on mortality in bedridden medical in-patients: a prospective randomised double-blind study

Evaluation of venous thromboembolism risk assessment models for hospital inpatients: the VTEAM evidence synthesis

Background

Pharmacological prophylaxis during hospital admission can reduce the risk of acquired blood clots (venous thromboembolism) but may cause complications, such as bleeding. Using a risk assessment model to predict the risk of blood clots could facilitate selection of patients for prophylaxis and optimise the balance of benefits, risks and costs.

Objectives

We aimed to identify validated risk assessment models and estimate their prognostic accuracy, evaluate the cost-effectiveness of different strategies for selecting hospitalised patients for prophylaxis, assess the feasibility of using efficient research methods and estimate key parameters for future research.

Design

We undertook a systematic review, decision-analytic modelling and observational cohort study conducted in accordance with Enhancing the QUAlity and Transparency Of health Research (EQUATOR) guidelines.

Setting

NHS hospitals, with primary data collection at four sites.

Participants

Medical and surgical hospital inpatients, excluding paediatric, critical care and pregnancy-related admissions.

Interventions

Prophylaxis for all patients, none and according to selected risk assessment models.

Main outcome measures

Model accuracy for predicting blood clots, lifetime costs and quality-adjusted life-years associated with alternative strategies, accuracy of efficient methods for identifying key outcomes and proportion of inpatients recommended prophylaxis using different models.

Results

We identified 24 validated risk assessment models, but low-quality heterogeneous data suggested weak accuracy for prediction of blood clots and generally high risk of bias in all studies. Decision-analytic modelling showed that pharmacological prophylaxis for all eligible is generally more cost-effective than model-based strategies for both medical and surgical inpatients, when valuing a quality-adjusted life-year at £20,000. The findings were more sensitive to uncertainties in the surgical population; strategies using risk assessment models were more cost-effective if the model was assumed to have a very high sensitivity, or the long-term risks of post-thrombotic complications were lower. Efficient methods using routine data did not accurately identify blood clots or bleeding events and several pre-specified feasibility criteria were not met. Theoretical prophylaxis rates across an inpatient cohort based on existing risk assessment models ranged from 13% to 91%.

Limitations

Existing studies may underestimate the accuracy of risk assessment models, leading to underestimation of their cost-effectiveness. The cost-effectiveness findings do not apply to patients with an increased risk of bleeding. Mechanical thromboprophylaxis options were excluded from the modelling. Primary data collection was predominately retrospective, risking case ascertainment bias.

Conclusions

Thromboprophylaxis for all patients appears to be generally more cost-effective than using a risk assessment model, in hospitalised patients at low risk of bleeding. To be cost-effective, any risk assessment model would need to be highly sensitive. Current evidence on risk assessment models is at high risk of bias and our findings should be interpreted in this context. We were unable to demonstrate the feasibility of using efficient methods to accurately detect relevant outcomes for future research.

Future work

Further research should evaluate routine prophylaxis strategies for all eligible hospitalised patients. Models that could accurately identify individuals at very low risk of blood clots (who could discontinue prophylaxis) warrant further evaluation.

Study registration

This study is registered as PROSPERO CRD42020165778 and Researchregistry5216.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: NIHR127454) and will be published in full in Health Technology Assessment; Vol. 28, No. 20. See the NIHR Funding and Awards website for further award information.

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.

American Society of Hematology 2021 guidelines for management of venous thromboembolism: prevention and treatment in patients with cancer

BACKGROUND

Venous thromboembolism (VTE) is a common complication among patients with cancer. Patients with cancer and VTE are at a markedly increased risk for morbidity and mortality.

OBJECTIVE

These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians, and other health care professionals in their decisions about the prevention and treatment of VTE in patients with cancer.

METHODS

ASH formed a multidisciplinary guideline panel balanced to minimize potential bias from conflicts of interest. The guideline development process was supported by updated or new systematic evidence reviews. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to assess evidence and make recommendations.

RESULTS

Recommendations address mechanical and pharmacological prophylaxis in hospitalized medical patients with cancer, those undergoing a surgical procedure, and ambulatory patients receiving cancer chemotherapy. The recommendations also address the use of anticoagulation for the initial, short-term, and long-term treatment of VTE in patients with cancer.

CONCLUSIONS

Strong recommendations include not using thromboprophylaxis in ambulatory patients receiving cancer chemotherapy at low risk of VTE and to use low-molecular-weight heparin (LMWH) for initial treatment of VTE in patients with cancer. Conditional recommendations include using thromboprophylaxis in hospitalized medical patients with cancer, LMWH or fondaparinux for surgical patients with cancer, LMWH or direct oral anticoagulants (DOAC) in ambulatory patients with cancer receiving systemic therapy at high risk of VTE and LMWH or DOAC for initial treatment of VTE, DOAC for the short-term treatment of VTE, and LMWH or DOAC for the long-term treatment of VTE in patients with cancer.

[Thrombotic Risk and Covid-19: Review of Current Evidence for a Better Diagnostic and Therapeutic Approach]

The new SARS-CoV-2 coronavirus has created an unprecedented global health problem, resulting in more than 250,000 confirmed deaths. The disease produced by this virus, called Covid-19, presents with variable clinical manifestations, from practically asymptomatic patients with catarrhal processes to severe pneumonias that rapidly evolve to acute respiratory distress syndrome (ARDS) and multiorgan failure. In recent weeks, papers have been published describing coagulation disorders and arterial and venous thrombotic complications in these patients, mainly among those admitted to intensive care units. The infection triggers an immune response, which causes different inflammatory mediators to be released into the blood. These include cytokines, which interact with platelets and different coagulation proteins, and promote thrombogenesis. One of the most widely studied coagulation markers in Covid-19 is D-dimer (DD), raised levels of which have prognostic implications, although the best cut-off point for the diagnosis of venous thromboembolism (VTE) in this population has not been clarified, nor has its usefulness in determining the intensity of thromboprophylaxis required in these patients. Until sufficiently robust information (preferably from well-designed clinical trials) is available, the recommendations of clinical practice guidelines for the prophylaxis, diagnosis and treatment of VTE should be followed in Covid-19 patients.

Effectiveness and safety of betrixaban extended prophylaxis for venous thromboembolism compared with standard-duration prophylaxis intervention in acute medically ill patients: a systematic literature review and network meta-analysis

Aims: To determine the clinical effectiveness and safety of venous thromboembolism (VTE) prophylaxis using US- and Europe-approved anticoagulants relative to extended-duration VTE prophylaxis with betrixaban. Low molecular weight heparins (LMWHs), unfractionated heparin (UFH), fondaparinux sodium and placebo were each compared to betrixaban, as standard-duration VTE prophylaxis for hospitalized, non-surgical patients with acute medical illness at risk of VTE. Materials and methods: A systematic literature review was conducted up to June 2019 to identify randomized controlled trials (RCTs) of VTE prophylaxis in hospitalized, non-surgical patients with acute medical illness at risk of VTE. Studies that reported the occurrence of VTE events (including death) and, where possible, major bleeding, from treatment initiation to 20-50 days thereafter were retrieved and extracted. A Bayesian fixed effect network meta-analysis was used to estimate efficacy and safety of betrixaban compared with standard-duration VTE prophylaxis. Results: Seven RCTs were analyzed which compared betrixaban, LMWHs, UFH, fondaparinux sodium, or placebo. There were significantly higher odds (median odds [95% credible interval]) of VTE with LMWHs (1.38 [1.12-1.70]), UFH (1.60 [1.05-2.46]), and placebo (2.37 [1.55-3.66]) compared with betrixaban. There were significantly higher odds of VTE-related death with placebo (7.76 [2.14-34.40]) compared with betrixaban. No significant differences were observed for the odds of major bleeding with all comparators, VTE-related death with any active standard-duration VTE prophylaxis, or of VTE with fondaparinux sodium, compared with betrixaban. Limitations and conclusions: In this indirect comparison, betrixaban was shown to be an effective regimen with relative benefits compared with LMWHs and UFH. This indicates that betrixaban could reduce the burden of VTE in at-risk hospitalized patients with acute medical illness who need extended prophylaxis, though without direct comparative evidence, stronger conclusions cannot be drawn.

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.

Compliance with Guidelines on Thromboprophylaxis for Acutely Admitted Medical Patients

INTRODUCTION

The risk of venous thromboembolism (VTE) is increased by more than 100-fold among hospitalised medical patients compared to subjects in the community. The Danish Council for the Use of Expensive Hospital Medicines has published national guidelines on thromboprophylaxis (TP) in which the risks of VTE and bleeding are balanced. We wanted to investigate the proportion of acutely admitted medical patients for whom thromboprophylaxis was indicated and to what extent the guidelines were followed.

METHODS

Data from patients hospitalised at two medical wards were screened. We registered the proportion of patients for whom mechanical or pharmacologic TP (MTP and PTP, respectively) was indicated and whether national guidelines were followed. All data extraction and analyses were performed retrospectively.

RESULTS

After exclusion criteria were applied, 340 cases remained. PTP was indicated in 26 patients (7.6%) but only 4 patients were treated besides 12 patients who were already in anticoagulant treatment at submission. Conversely, 8/306 patients, in whom TP was not indicated, were started on PTP. MTP was indicated in 8/340 patients (2.4%) but therapy was not initiated in any of them. The majority (320/340, 94.1%) of cases was managed in accordance with existing guidelines. However, this high proportion was mainly explained by the large number of untreated patients, where TP was not indicated.

CONCLUSION

A large proportion of hospitalised medical patients was managed in conflict with national guidelines. A systematic approach to TP in patients with acute medical illness should be implemented. Plain language summary available for this article.

Should all acutely ill medical patients be treated with antithrombotic drugs?

After reports from observational studies suggesting an association between acutely ill medical patients and venous thromboembolism (VTE), interventional trials with anticoagulants drugs have demonstrated a significant reduction of VTE during and immediately after hospitalisation. Although several guidelines suggest the clinical relevance of reducing this outcome, there is a low tendency to use anticoagulants in patients hospitalised for acute medical illness. We speculated that such underuse may be dependent on a low perception that patients included in the trials are actually at risk of thromboembolism. Therefore, the aim of this study was to analyse the clinical settings included in the interventional trials and their relationship with thrombotic risk. Analysis of interventional trials revealed that the majority of patients included in the trials (about 80%) were affected by heart failure, acute respiratory syndrome or infections. Among these three illnesses, literature data shows an association with venous thrombosis only in patients with acute infections; this finding was, however, supported only by retrospective study. On the contrary, there is scarce or no evidence that heart failure and acute respiratory syndrome are associated with venous thrombosis. These data underscore the need of better defining the thrombotic risk profile of acutely ill medical patients included in interventional trials with anticoagulants.

Nadroparin for the prevention of venous thromboembolism in nonsurgical patients: a systematic review and meta-analysis

Anticoagulant thromboprophylaxis with low molecular weight heparin is widely used in nonsurgical settings. To obtain best estimates of the effects of nadroparin for the prevention of venous thromboembolism (VTE) in nonsurgical patients, we conducted a systematic review and meta-analysis. Data sources were Medline, Embase, and Cochrane Library supplemented with conference abstracts, without language restrictions. Selection criteria were randomized controlled trials with nadroparin at prophylactic dose in adult nonsurgical patients. Main efficacy outcomes were major VTE (the composite of symptomatic deep vein thrombosis, symptomatic pulmonary embolism, asymptomatic proximal deep vein thrombosis and VTE-related death) and symptomatic VTE. The main safety outcome was major bleeding. We expressed treatment effects as risk ratios. Ten studies (4 vs. placebo or no treatment, 4 vs. UFH, 1 vs. fondaparinux and 1 vs. warfarin) enrolling a total of 7658 patients were included. In comparison with placebo, nadroparin reduced major VTE by about one-half (RR 0.48, 95% CI 0.24-0.97) with a consistent effect on symptomatic VTE (RR 0.69, 95% CI 0.46-1.05) and no increase in major bleeding (RR 1.51, 95% CI 0.40-5.79). In comparison with other pharmacological prophylaxis, nadroparin was similarly efficacious for prevention of major VTE (RR 1.14, 95% CI 0.63-2.10) and symptomatic VTE (RR 1.10, 95% CI 0.51-2.35) and produced similar effects on major bleeding (RR 0.60, 95% CI 0.25-1.50). Five studies were open label, and for three of these the adjudication method was not described or not blinded. In nonsurgical populations at risk of VTE, nadroparin reduced VTE by about one half compared with placebo or no treatment and appeared similarly effective and safe as other prophylactic anticoagulants.

Quantification of the External Validity of Randomized Controlled Trials Supporting Clinical Care Guidelines: The Case of Thromboprophylaxis

BACKGROUND

Clinical guidelines are based on the results of several randomized controlled trials. However, due to the stringent exclusion criteria of these trials, their external validity may be low. We aimed to evaluate the external validity of the randomized controlled trials cited in the American College of Chest Physicians guidelines for the use of pharmacological thromboprophylaxis in hospitalized medical patients.

METHODS

We conducted a cross-sectional, chart-review study of a random sample of patients admitted between July 1, 2013 and June 30, 2014 to the Internal Medicine ward of a large Canadian teaching university hospital. We identified the proportion of our population presenting exclusion criteria used in the randomized controlled trials cited in support of clinical care guidelines on thromboprophylaxis in the medical setting.

RESULTS

Nine trials were identified for a total of 28,793 included patients following 23 distinct exclusion criteria. We included 429 patients. Median age was 65 years (interquartile ratio 51-77 years), and 236 (55%) were males. Of those not already anticoagulated at admission (n = 351), between 26% and 67% (weighted average, 51%) of our population presented at least one exclusion criterion, making them ineligible to be enrolled in randomized controlled trials. When restricting our population to patients with an indication for thromboprophylaxis based on a Padua risk score at admission ≥4, 21% to 76% (weighted average 55%) were ineligible to be enrolled in individual trials.

CONCLUSIONS

Our cross-sectional study illustrates that the external validity of randomized controlled trials cited in the guidelines was low in our population, and lower when applying the risk-stratification tool recommended by guidelines. This can bias the clinicians toward treating patients that were not represented in the supporting evidence.

Effect of thromboprophylaxis with anticoagulant drugs on the incidence of arterial thrombotic events in medical inpatients: a systematic review

Pharmacological prophylaxis of venous thromboembolism (VTE) is recommended for medical inpatients. Since arterial thrombosis (AT) shares some risk factors with VTE, it would be reasonable to assess the efficacy of thromboprophylaxis by considering both VTE and AT as outcome events. We performed a systematic review and meta-analysis of phase III RCTs on thromboprophylaxis in medical inpatients, to evaluate the quality of reporting and the incidence of AT, and the effect of thromboprophylaxis with anticoagulants on AT incidence. Studies were identified by a combined search strategy until May 2015. Differences in outcomes among groups were expressed as pooled odds ratios (OR) and 95 % confidence intervals (CI). Statistical heterogeneity was assessed by I (2) statistic. Twenty phase III RCTs, encompassing 54,742 patients, were included; of these, 3 (15 %) reported on AT as a pre-defined secondary outcome and 8 (40 %) on at least one AT outcome. Raw-unweighed incidence of fatal MI in the three RCTs is 0.37 % in patients receiving unfractionated heparin or enoxaparin, and 0.38 % in controls (OR 0.97, 95 % CI 0.62-1.52; I (2) = 0 %). A non-statistically significant increase in AT is reported in patients on enoxaparin compared to control (OR 1.95, 95 % CI 0.89-4.27; I (2) = 13 %). AT is underreported in RCTs on VTE prophylaxis in medical inpatients. Published data suggest that incidence of fatal MI in these patients may be clinically relevant. Insufficient data are available to draw firm conclusions on the effects of thromboprophylaxis with anticoagulants on AT incidence in this setting.

Safety and efficacy of pharmacological thromboprophylaxis for hospitalized patients with cirrhosis: a single-center retrospective cohort study

BACKGROUND

Hospitalized patients with cirrhosis are at increased risk for venous thromboembolism (VTE). The benefits and risks of pharmacological thromboprohylaxis in these patients have not been well studied.

OBJECTIVES

To examine the safety and efficacy of pharmacological VTE prophylaxis in hospitalized cirrhotic patients.

PATIENTS/METHODS

Retrospective cohort study of patients with cirrhosis hospitalized at an academic tertiary care referral center over a 5-year period.

RESULTS

Six hundred hospital admissions accounting for 402 patients were included. VTE prophylaxis was administered during 296 (49%) admissions. Patients receiving VTE prophylaxis were older (59 years vs. 55 years, P < 0.001), had longer lengths of stay (9.6 days vs. 6.8 days, P = 0.002), and lower Model for End-Stage Liver Disease scores (13.2 vs. 16.1, P < 0.001). In-hospital bleeding events (8.1% vs. 5.5%, P = 0.258), gastrointestinal bleeding events (3.0% vs. 3.2% P = 0.52), new VTE events (2.37% vs. 1.65%, P = 0.537), and mortality (8.4% vs. 7.3%, P = 0.599) were similar in the two groups. VTE prophylaxis did not reduce the risk of VTE (odds ratio 0.94, 95% confidence interval 0.23-3.71), and patients receiving unfractionated heparin, but not low molecular weight heparin, were at increased risk for in-hospital bleeding events (odds ratio 2.38, 95% confidence interval 1.15-4.94 vs. 0.87, 0.37-2.05, respectively).

CONCLUSION

The rate of VTE in this cohort of hospitalized cirrhotic patients was low and was unaffected by pharmacological thromboprophylaxis. Unfractionated heparin was associated with an increased risk for in-hospital bleeding, suggesting that if thromboprophylaxis is indicated, low molecular weight heparin may be favored.

Venous thromboembolism prophylaxis with anticoagulation in septic patients: a prospective cohort study

BACKGROUND

Venous thromboembolism (VTE) is a feared complication during hospitalization. The practice of administering pharmacological prophylaxis is highly endorsed despite failure of studies to show reduction in mortality.

AIM

: To determine the benefit of VTE prophylaxis in acutely ill medical patients with sepsis.

METHODS

A prospective cohort, with enrollment between January 2010 and April 2011. Patients were detected in four medicine departments at a university-affiliated hospital and followed for 90 days for pre-specified outcomes. We included all septic patients at high VTE risk defined by Padua score ≥ 4. The primary outcome was 30-day mortality. Incidence of pulmonary embolism, deep vein thrombosis or major bleeding episodes at 30 and 90 days, and 90-day mortality were secondary outcomes.

RESULTS

A total of 1540 patients were identified, of which 720 (55%) were at high risk for VTE and included. A total of 213 (29.6%) patients received prophylaxis. VTE occurred in 6 control patients and 2 treated (0.9 and 1.2%, respectively, RR 0.79, CI: 0.16-3.95). Major bleeding events occurred in 4 (0.8%) control and 7 (3.3%) treated patients (RR 4.1, CI: 1.24-14.08, P = 0.01). After adjusting for covariates, VTE prophylaxis conferred no 30- or 90-day mortality benefit (OR 1.24, CI: 0.79-1.93 and OR 1.47, CI: 0.99-2.17, respectively). Lack of significant benefit with prophylaxis persisted after propensity-score matching (OR for 30-day mortality 1.01, CI: 0.66-1.55).

CONCLUSIONS

In acutely ill inpatients with sepsis, no significant benefit was demonstrated for VTE prophylaxis, with higher rates of bleeding. The risk-benefit ratio of this intervention should be carefully examined.

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.

Heparin for the prevention of venous thromboembolism in acutely ill medical patients (excluding stroke and myocardial infarction)

BACKGROUND

Venous thromboembolic disease has been extensively studied in surgical patients. The benefit of thromboprophylaxis is now generally accepted, but it is medical patients who make up the greater proportion of the hospital population. Medical patients differ from surgical patients with regard to their health and the pathogenesis of thromboembolism and the impact that preventative measures can have. The extensive experience from thromboprophylaxis studies in surgical patients is therefore not necessarily applicable to non-surgical patients. This is an update of a review first published in 2009.

OBJECTIVES

To determine the effectiveness and safety of heparin (unfractionated heparin or low molecular weight heparin) thromboprophylaxis in acutely ill medical patients admitted to hospital, excluding those admitted to hospital with an acute myocardial infarction or stroke (ischaemic or haemorrhagic) or those requiring admission to an intensive care unit.

SEARCH METHODS

For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched November 2013) and CENTRAL (2013, Issue 10).

SELECTION CRITERIA

Randomised controlled trials comparing unfractionated heparin (UFH) or low molecular weight heparin (LMWH) with placebo or no treatment, or comparing UFH with LMWH.

DATA COLLECTION AND ANALYSIS

One review author identified possible trials and a second review author confirmed their eligibility for inclusion in the review. Two review authors extracted the data. Disagreements were resolved by discussion. We performed the meta-analysis using a fixed-effect model with the results expressed as odds ratios (ORs) with 95% confidence intervals (CIs).

MAIN RESULTS

Sixteen studies with a combined total of 34,369 participants with an acute medical illness were included in this review. We identified 10 studies comparing heparin with placebo or no treatment and six studies comparing LMWH to UFH. Just under half of the studies had an open-label design, putting them at a risk of performance bias. Descriptions of random sequence generation and allocation concealment were missing in most of the studies. Heparin reduced the odds of deep vein thrombosis (DVT) (OR 0.38; 95% CI 0.29 to 0.51; P < 0.00001). The estimated reductions in symptomatic non-fatal pulmonary embolism (PE) (OR 0.46; 95% CI 0.19 to 1.10; P = 0.08), fatal PE (OR 0.71; 95% CI 0.43 to 1.15; P = 0.16) and in combined non-fatal PE and fatal PE (OR 0.65; 95% CI 0.42 to 1.00; P = 0.05) associated with heparin were imprecise. Heparin resulted in an increase in major haemorrhage (OR 1.81; 95% CI 1.10 to 2.98; P = 0.02). There was no clear evidence that heparin had an effect on all-cause mortality and thrombocytopaenia. Compared with UFH, LMWH reduced the risk of DVT (OR 0.77; 95% CI 0.62 to 0.96; P = 0.02) and major bleeding (OR 0.43; 95% CI 0.22 to 0.83; P = 0.01). There was no clear evidence that the effects of LMWH and UFH differed for the PE outcomes, all-cause mortality and thrombocytopaenia.

AUTHORS' CONCLUSIONS

The data from this review describe a reduction in the risk of DVT in patients presenting with an acute medical illness who receive heparin thromboprophylaxis. This needs to be balanced against an increase in the risk of bleeding associated with thromboprophylaxis. The analysis favoured LMWH compared with UFH, with a reduced risk of both DVT and bleeding.

Comparison of the efficacy and safety of low molecular weight heparins for venous thromboembolism prophylaxis in medically ill patients

OBJECTIVE

To conduct a systematic review and mixed-treatment comparison (MTC) meta-analysis to compare the efficacy and safety of low molecular weight heparins (LMWHs) for venous thromboembolism (VTE) prophylaxis in hospitalized medically ill patients. As a secondary objective we compared all therapies within the network to each other.

METHODS

We conducted a systematic literature search for randomized trials that evaluated pharmacologic VTE prophylaxis in hospitalized medically ill patients. We conducted a traditional meta-analysis for all pairwise comparisons using a random effects model, reporting relative risks (RRs) and 95% confidence intervals for each outcome. To determine the relative efficacy and safety of included therapies we conducted a MTC meta-analysis using a Bayesian framework, reporting odds ratios (OR) and 95% credible intervals.

RESULTS

Twenty trials met inclusion criteria. Enoxaparin, dalteparin, nadroparin and certoparin were the LMWHs evaluated although none in direct comparative trials. Upon MTC, the relative efficacy of all LMWHs was similar in preventing mortality and VTE as well as in the odds of major and minor bleeding. Dalteparin was not included in the network to evaluate deep vein thrombosis (DVT) and pulmonary embolism (PE) due to lack of reported data and the remaining LMWHs were found to be similar in relative efficacy in preventing these outcomes.

LIMITATIONS

Traditional meta-analysis was not possible for many drug comparisons made within the MTC. Heterogeneity was observed in several of the traditional meta-analyses although this may be an inherent limitation of the studied population. Overall rarity of events contributed to imprecise estimates demonstrated by the wide confidence intervals.

CONCLUSIONS

Enoxaparin, dalteparin, nadroparin and certoparin are similar in relative efficacy for the prevention of mortality and VTE and in the odds of major or minor bleeding while enoxaparin, nadroparin and certoparin are similar in relative efficacy for the prevention of PE and DVT in hospitalized medical patients.

Lack of evidence to support thromboprophylaxis in hospitalized medical patients with cancer

BACKGROUND

The administration of anticoagulant thromboprophylaxis for all patients with cancer who are hospitalized for acute medical illness is considered standard practice and strongly recommended in clinical guidelines. These recommendations are extrapolated from randomized controlled prophylaxis trials not specifically conducted in cancer cohorts. Because hospitalized patients with cancer constitute a unique population with increased risk of venous thromboembolic events and major hemorrhage, validation of the efficacy and safety of primary thromboprophylaxis in this population is critical. We sought to summarize the rates of venous thromboembolic events and major bleeding episodes among hospitalized patients with cancer who were receiving anticoagulant therapy compared with placebo.

METHODS

A systematic literature search strategy was conducted using MEDLINE, EMBASE, and the Cochrane Register of Controlled Trials. Two reviewers independently extracted data onto standardized forms. The primary end points were all venous thromboembolic events. Secondary end points included major bleeding episodes and symptomatic venous thromboembolic events. Pooled analysis with relative risk using a random effect model was used as the primary measurement.

RESULTS

A total of 242 citations were identified by the literature search. Of these, 3 placebo-controlled randomized trials included venous thromboembolic events as a primary outcome and were analyzed according to cancer subgroups. The pooled relative risk of venous thromboembolic events was 0.91 (95% confidence interval, 0.21-4.0; I(2): 68%) among hospitalized patients with cancer who were receiving thromboprophylaxis compared with placebo. None of the trials reported the rates of symptomatic venous thromboembolic events or major bleeding episodes according to cancer status.

CONCLUSIONS

The risks and benefits of primary thromboprophylaxis with anticoagulant therapy in hospitalized patients with cancer are not known. This is especially relevant because numerous Medicare-type pay-for-performance incentives mandate prophylaxis specifically in patients with cancer.

The incidence of pulmonary embolism during deep vein thrombosis

Among life-threatening cardiovascular diseases, pulmonary embolism (PE) is the third most common after myocardial infarction and stroke. PE is a manifestation of venous thromboembolism (VTE). PE shares risk factors with deep vein thrombosis (DVT) and is regarded as a consequence of DVT rather than a separate clinical entity. Risk factors for VTE include major surgery, major trauma, high age, myocardial infarction, chronic heart failure, prolonged immobility, malignancy, thrombophilia and prior VTE. It is, however, important to recognize that these factors are not equally important and not equally common in patients with PE and DVT, respectively. Compared with DVT, PE is more often associated with major surgery, major trauma, high age, myocardial infarction and chronic heart failure, whereas malignancy and thrombophilia primarily are clinical predictors of DVT. In patients with prior VTE the initial clinical manifestation strongly predicts the manifestation of recurrent episodes, i.e. patients with previous PE are more likely to develop recurrent PE than DVT while patients with DVT predominantly are at risk of recurrent DVT.

Venous thrombosis risk assessment in medical inpatients: the medical inpatients and thrombosis (MITH) study

BACKGROUND

We sought to define the risk factors present at admission for venous thromboembolism (VTE) in medical inpatients and develop a risk model for clinical use.

METHODS

Between January 2002 and June 2009, 299 cases of hospital-acquired VTE were frequency matched to 601 controls. Records were abstracted using a standard form for characteristics of the thrombosis, medical conditions and other risk factors. Weighted logistic regression and survey methods were used to develop a risk model for hospital-acquired VTE that was validated by bootstrapping.

RESULTS

VTE complicated 4.6 per 1000 admissions. Two risk assessment models were developed, one using laboratory data available at admission (Model 1) and the other excluding laboratory data (Model 2). Model 1 consisted of the following risk factors (points): history of congestive heart failure (5), history of inflammatory disease (4), fracture in the past 3 months (3), history of VTE (2), history of cancer in the past 12 months (1), tachycardia (2), respiratory dysfunction (1), white cell count ≥ 11 × 10(9) /L (1), and platelet count ≥ 350 × 10(9) /L (1). Model 2 was similar, except respiratory dysfunction had 2 points and white cell and platelet counts were removed. The c-statistic for Model 1 was 0.73 (95% CI 0.70, 0.77) and for Model 2 0.71 (95% CI 0.68, 0.75).

CONCLUSIONS

We present a VTE risk assessment model for use in medical inpatients. The score is simple and relies on information known at the time of admission and typically collected in all medical inpatients. External validation is needed.

Venous thromboembolism and the utility of the Padua Prediction Score in patients with sepsis admitted to internal medicine departments

BACKGROUND

Sepsis is prevalent in internal medicine (IM) departments. Elderly patients with sepsis and chronic medical conditions are at an increased risk for venous thromboemolism (VTE). The objective of this study was to assess the rate of VTE and the accuracy of the Padua Prediction Score (PPS) to predict VTE in patient with sepsis admitted to IM departments.

METHODS

We prospectively collected data on septic patients admitted to IM departments in a community-based medical center. Additionally, we retrospectively collected VTE risk factors and events throughout a 1-year post hospitalization period. We computed the PPS for every patient, and analyzed the data accordingly.

RESULTS

In total, 1080 patients were included in the study. The mean age was 74.68 ± 16.1 years. The average PPS was 4.86 ± 2.26, and 71.2% of the patients had a positive PPS. Only 17.8% of the patients received anticoagulant prophylaxis during their hospital stay. Seven patients had VTE on admission, 14 (1.29%) acquired in-hospital VTE, and 7 (0.65%) had VTE post discharge throughout 1 year. In all, 21.9% patients died during hospitalization, and the overall survival rate was 64%. PPS was not correlated with anticoagulant administration (P = 0.36), in-hospital VTE (P = 0.23) or 1-year VTE (P = 0.40), but was significantly associated with in-hospital death and survival (P < 0.0001).

CONCLUSION

The rate of VTE in medical patients with sepsis in IM departments is low, and PPS lacks granularity in detecting patients at risk of acquiring it. In this population, a positive PPS is highly associated with death, and may reflect a more general co-morbidity and disease severity index.

Thromboprophylaxis in nonsurgical patients

Venous thromboembolism (VTE) is an important cause of preventable morbidity and mortality in medically ill patients. Randomized controlled trials indicate that pharmacologic prophylaxis reduces deep venous thrombosis (relative risk [RR] = 0.46; 95% confidence interval [CI], 0.36-0.59) and pulmonary embolism (RR = 0.49; 95% CI, 0.33-0.72) with a nonsignificant trend toward more bleeding (RR = 1.36; 95% CI, 0.80-2.33]. Low-molecular-weight heparin (LMWH) and unfractionated heparin are equally efficacious in preventing deep venous thrombosis (RR = 0.85; 95% CI, 0.69-1.06) and pulmonary embolism (RR = 1.05; 95% CI, 0.47-2.38), but LMWH is associated with significantly less major bleeding (RR = 0.45; 95% CI, 0.23-0.85). LMWH is favored for VTE prophylaxis in critically ill patients. New VTE and bleeding risk stratification tools offer the potential to improve the risk-benefit ratio for VTE prophylaxis in medically ill patients. Intermittent pneumatic compression devices should be used for VTE prophylaxis in patients with contraindications to pharmacologic prophylaxis. Graduated compression stockings should be used with caution. VTE prevention in medically ill patients using extended-duration VTE prophylaxis and new oral anticoagulants warrant further investigation. VTE prophylaxis prescription and administration rates are suboptimal and warrant multidisciplinary performance improvement strategies.

Thromboprophylaxis in non-surgical cancer patients

Acutely ill medical patients with cancer and cancer patients requiring non-surgical therapy are considered as non-surgical cancer patients and are at moderate to high risk of venous thromboembolism (VTE): approximately 10-30% of these patients may develop asymptomatic or symptomatic deep-vein thrombosis (DVT) or pulmonary embolism (PE), and the latter is a leading contributor to deaths in hospital. Other medical conditions associated with a high risk of VTE include cardiac disease, respiratory disease, inflammatory bowel disease, rheumatological and infectious diseases. Pre-disposing risk factors in non-surgical cancer patients include a history of VTE, immobilisation, history of metastatic malignancy, complicating infections, increasing age, obesity hormonal or antiangiogenic therapies, thalidomide and lenalidomide therapy. Heparins, both unfractionated (UFH) and low molecular weight heparin (LMWH) and fondaparinux have been shown to be effective agents in prevention of VTE in the medical setting with patients having a history of cancer. UFH and LMWH along with semuloparin also have a role in outpatients with cancer receiving chemotherapy. However, it has not yet been possible to demonstrate a significant effect on mortality rates in this population. UFH has a higher rate of bleeding complications than LMWH. 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 LMWH, or fondaparinux for the prevention of VTE in cancer patients with acute medical illnesses and UFH for those with significant severe renal impairment. For ambulatory cancer patients undergoing chemotherapy we recommend LMWH or semuloparin. These are safe and effective agents in the thromboprophylaxis of non-surgical cancer patients.

Venous thromboembolism prophylaxis of acutely ill hospitalized medical patients. Are we over-treating our patients?

Venous thromboembolism (VTE) is prevalent and is associated with dire consequences. Many VTE events are related to medical hospitalization, and some of these events are avoidable when appropriate measures are taken. Despite the current knowledge of the prevalence and burden of this disease, many internists are reluctant to prescribe pharmacological prophylaxis to "at-risk" medical inpatients. The purpose of this review is to analyze the reasons for deferring such treatment, in view of the facts as presented in the medical literature. We believe that while the literature supports further emphasis on education and support systems, Internists are deficient of validated tools to decide upon their patient's true risk of clinically overt disease.

Venous thromboembolism prophylaxis of acutely ill hospitalized medical patients. Are we under-treating our patients?

Venous thromboembolism (VTE) is frequent in patients hospitalized in Internal Medicine wards. It carries a considerable morbidity and mortality. Recommendations for use of anticoagulation are graded 1A in leading evidence-based consensus guidelines. Implementation of these guidelines is suboptimal. Lack of awareness seems to be an important factor for the low implementation rate of thromboprophylaxis in Internal Medicine wards, but other factors may be equally important: some clinicians find the data favoring thromboprophylaxis unconvincing or believe that pharmacological prevention is too risky for the average medical inpatient. The following review will show that although there is a dispute about the clinical importance of some manifestations of thromboembolic disease, anticoagulation significantly reduces the risk for clinically relevant VTE. The bleeding risk in most patients is low and does not outweigh the benefit of treatment. Pharmacological or mechanical thromboprophylaxis is cost-effective when administered to at-risk patients. Better awareness and judicious use of risk assessment models should help the attending physician to balance the risk of VTE against the potential bleeding risk.

Low-molecular-weight heparin and mortality in acutely ill medical patients

BACKGROUND

Although thromboprophylaxis reduces the incidence of venous thromboembolism in acutely ill medical patients, an associated reduction in the rate of death from any cause has not been shown.

METHODS

We conducted a double-blind, placebo-controlled, randomized trial to assess the effect of subcutaneous enoxaparin (40 mg daily) as compared with placebo--both administered for 10±4 days in patients who were wearing elastic stockings with graduated compression--on the rate of death from any cause among hospitalized, acutely ill medical patients at participating sites in China, India, Korea, Malaysia, Mexico, the Philippines, and Tunisia. Inclusion criteria were an age of at least 40 years and hospitalization for acute decompensated heart failure, severe systemic infection with at least one risk factor for venous thromboembolism, or active cancer. The primary efficacy outcome was the rate of death from any cause at 30 days after randomization. The primary safety outcome was the rate of major bleeding during and up to 48 hours after the treatment period.

RESULTS

A total of 8307 patients were randomly assigned to receive enoxaparin plus elastic stockings with graduated compression (4171 patients) or placebo plus elastic stockings with graduated compression (4136 patients) and were included in the intention-to-treat population. The rate of death from any cause at day 30 was 4.9% in the enoxaparin group as compared with 4.8% in the placebo group (risk ratio, 1.0; 95% confidence interval [CI], 0.8 to 1.2; P=0.83). The rate of major bleeding was 0.4% in the enoxaparin group and 0.3% in the placebo group (risk ratio, 1.4; 95% CI, 0.7 to 3.1; P=0.35).

CONCLUSIONS

The use of enoxaparin plus elastic stockings with graduated compression, as compared with elastic stockings with graduated compression alone, was not associated with a reduction in the rate of death from any cause among hospitalized, acutely ill medical patients. (Funded by Sanofi; LIFENOX ClinicalTrials.gov number, NCT00622648.).

Areas of uncertainty in prophylaxis of venous thromboembolism in unselected subjects

In the last decade, parenteral anticoagulants have proven to be effective in the prevention of venous thromboembolism (VTE) in patients admitted to hospitals. Despite this, some registry studies have shown that pharmacological prophylaxis is still widely underused. We performed a literature search to identify important knowledge gaps in the use of VTE prophylaxis that were not addressed by previous published reports. MEDLINE and HighWire databases covering the years 1999-2009 were searched; only clinical trials of unselected adult subjects were included. Two reviewers independently selected studies and extracted data on inclusion and exclusion criteria, age, weight, comorbidities, study designs, and endpoints. Five of 113 relevant studies were identified from the literature search. Knowledge gaps were disclosed in subject inclusion, exclusion, and stratification regarding young age, under- and overweight, comorbidities, and the selection of clinically significant endpoints. Uncertainties in the dosage, risk stratification of subjects, and effect on hard endpoints as prevention of pulmonary embolism or reduction of mortality reduce the impact of VTE prevention clinical trials.

Diet as prophylaxis and treatment for venous thromboembolism?

BACKGROUND

Both prophylaxis and treatment of venous thromboembolism (VTE: deep venous thrombosis (DVT) and pulmonary emboli (PE)) with anticoagulants are associated with significant risks of major and fatal hemorrhage. Anticoagulation treatment of VTE has been the standard of care in the USA since before 1962 when the U.S. Food and Drug Administration began requiring randomized controlled clinical trials (RCTs) showing efficacy, so efficacy trials were never required for FDA approval. In clinical trials of 'high VTE risk' surgical patients before the 1980s, anticoagulant prophylaxis was clearly beneficial (fatal pulmonary emboli (FPE) without anticoagulants = 0.99%, FPE with anticoagulants = 0.31%). However, observational studies and RCTs of 'high VTE risk' surgical patients from the 1980s until 2010 show that FPE deaths without anticoagulants are about one-fourth the rate that occurs during prophylaxis with anticoagulants (FPE without anticoagulants = 0.023%, FPE while receiving anticoagulant prophylaxis = 0.10%). Additionally, an FPE rate of about 0.012% (35/28,400) in patients receiving prophylactic anticoagulants can be attributed to 'rebound hypercoagulation' in the two months after stopping anticoagulants. Alternatives to anticoagulant prophylaxis should be explored.

METHODS AND FINDINGS

The literature concerning dietary influences on VTE incidence was reviewed. Hypotheses concerning the etiology of VTE were critiqued in relationship to the rationale for dietary versus anticoagulant approaches to prophylaxis and treatment.Epidemiological evidence suggests that a diet with ample fruits and vegetables and little meat may substantially reduce the risk of VTE; vegetarian, vegan, or Mediterranean diets favorably affect serum markers of hemostasis and inflammation. The valve cusp hypoxia hypothesis of DVT/VTE etiology is consistent with the development of VTE being affected directly or indirectly by diet. However, it is less consistent with the rationale of using anticoagulants as VTE prophylaxis. For both prophylaxis and treatment of VTE, we propose RCTs comparing standard anticoagulation with low VTE risk diets, and we discuss the statistical considerations for an example of such a trial.

CONCLUSIONS

Because of (a) the risks of biochemical anticoagulation as anti-VTE prophylaxis or treatment, (b) the lack of placebo-controlled efficacy data supporting anticoagulant treatment of VTE, (c) dramatically reduced hospital-acquired FPE incidence in surgical patients without anticoagulant prophylaxis from 1980 - 2010 relative to the 1960s and 1970s, and (d) evidence that VTE incidence and outcomes may be influenced by diet, randomized controlled non-inferiority clinical trials are proposed to compare standard anticoagulant treatment with potentially low VTE risk diets. We call upon the U. S. National Institutes of Health and the U.K. National Institute for Health and Clinical Excellence to design and fund those trials.

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.

The paradox of ventilator-associated pneumonia prevention measures

There is a striking paradox in the literature supporting high-profile measures to reduce ventilator-associated pneumonia (VAP): many studies show significant reductions in VAP rates but almost none show any impact on patients' duration of mechanical ventilation, length of stay in the intensive care unit and hospital, or mortality. The paradox is largely attributable to lack of specificity in the VAP definition. The clinical and microbiological criteria for VAP capture a population of patients with an array of conditions that range from serious to benign. Many of the benign events are manifestations of bacterial colonization superimposed upon pulmonary edema, atelectasis, or other non-infectious processes. VAP prevention measures that work by decreasing bacterial colonization preferentially lower the frequency of these mislabelled, more benign events. In addition, misclassification obscures detection of an impact of prevention measures on bona fide pneumonias. Together, these effects create the possibility of the paradox where a prevention measure may have a large impact on VAP rates but minimal impact on patients' outcomes. The paradox makes changes in VAP rates alone an unreliable measure of whether VAP prevention measures are truly beneficial to patients and behooves us to measure their impact on patient outcomes before advocating their adoption.

Evaluating the effectiveness of a deep-vein thrombosis prophylaxis protocol in orthopaedics and traumatology

RATIONALE, AIMS AND OBJECTIVES

To evaluate the effectiveness of the deep-vein thrombosis (DVT) prophylaxis protocol for adult patients in a general orthopaedics and traumatology clinic.

METHOD

We followed the DVT prophylaxis protocol in 1326 (776 female, 550 male) of 2114 adult patients admitted to the Department of Orthopaedics and Traumatology in Goztepe Research and Training Hospital. They were followed for symptomatic DVT and possible complications of low-molecular-weight heparin (LMWH) therapy. A Doppler ultrasonography (US) was performed when DVT was suspected. The medical information treatment protocols of DVT patients were recorded.

RESULTS

Doppler US was performed in 58 patients with suspected DVT. Six of these patients were diagnosed with DVT. The side effects of LMWH were upper gastrointestinal bleeding (0.5%), widespread ecchymosis of the extremities (1.9%) and heparin-induced thrombocytopenia (0.16%).

CONCLUSION

Symptomatic DVT occurrences were similar to those in medical literature; however, there were fewer side effects of LMWH than reported in literature.

How complete is the evidence for thromboembolism prophylaxis in general medicine patients? A meta-analysis of randomized controlled trials

OBJECTIVES

Guidelines recommend pharmacologic prophylaxis for hospitalized medical patients at increased risk of thromboembolism. Despite recommendations, multiple studies demonstrate underutilization. Factors contributing to underutilization include uncertainty that prophylaxis reduces clinically relevant events, as well as questions about the best form of prophylaxis. We sought to determine whether prophylaxis decreases clinically significant events and to answer whether unfractionated heparin (UFH) or low molecular weight heparin (LMWH) is either more effective or safer.

DATA SOURCES

The MEDLINE, EMBASE, CINAHL, and Cochrane databases were searched through June 2008. Relevant bibliographies and conference proceedings were reviewed and LMWH manufacturers were contacted.

STUDY SELECTION

Randomized trials comparing UFH or LMWH to control, as well as head-to-head comparisons of UFH to LMWH in general medicine patients.

DATA EXTRACTION AND ANALYSIS

End points of deep venous thrombosis (DVT), proximal or symptomatic DVT, pulmonary embolism, mortality, bleeding, and thrombocytopenia were extracted from individual trials. Pooled relative risks were calculated using random effects modeling.

RESULTS

We identified 8 trials comparing prophylaxis to control, and 6 trials comparing UFH to LMWH. Prophylaxis reduced DVT (relative risk [RR] = 0.55; 95% confidence interval [CI]: 0.36-0.92), proximal DVT (RR = 0.46; 95% CI: 0.31-0.69), and pulmonary embolism (RR = 0.70; 95% CI: 0.53-0.93). Prophylaxis increased the risk of any bleeding (RR = 1.54; 95% CI: 1.15-2.06) but not major bleeding. Across trials comparing LMWH to UFH, there were no differences for any outcome.

CONCLUSIONS

Among medical patients, pharmacologic prophylaxis reduced the risk of thromboembolism without increasing risk of major bleeding. The current literature does not demonstrate superior efficacy of UFH or LMWH.

Audit of anticoagulant thromboprophylaxis in hospitalized oncology patients

BACKGROUND

Venous thromboembolism (VTE) is a significant problem in oncology patients. VTE prophylaxis is underutilized in hospitalized medical patients, but there are few data for the appropriateness and frequency of its use in the oncology subgroup. We aimed to document local practice.

METHODS

A cross-sectional chart review of all hospitalized patients cared for by the Christchurch Hospital Oncology Service was carried out during two defined 4-week periods. Assessment for indications and contraindications to prophylactic anticoagulation was based on the 2004 American College of Chest Physicians evidence-based consensus guidelines.

RESULTS

Of 113 admissions to the oncology service, 38 (33.6%) had indications for prophylactic anticoagulation. However, 23 of these also had contraindications, leaving only 15 (13%) admissions where prophylactic anticoagulation was deemed appropriate. Only one was appropriately given prophylactic anticoagulation.

CONCLUSION

Only a minority of hospitalized oncology patients are appropriate for prophylactic anticoagulation. Where it is suitable, however, it is poorly utilized locally. Local promotion of VTE prophylaxis and further study of this subgroup of hospitalized medical patients may improve uptake of this practice and attenuate morbidity from VTE.