-
Spinal Cord Aug 2013The objective of this study is to systematically review and estimate the effect of heparin for thromboprophylaxis in patients with acute spinal cord injury (SCI). (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
The objective of this study is to systematically review and estimate the effect of heparin for thromboprophylaxis in patients with acute spinal cord injury (SCI).
METHODS
We searched the PubMed database up to February 2013. Only randomized control trials (RCTs), quasi-RCTs, cohorts, case-control and cross-sectional studies were included. The incidence of venous thromboembolism (VTE) and major bleeding complication were recorded as the endpoints. The summary relative risks (RR) were calculated by meta-analysis.
RESULTS
A total of 18 studies with 2578 patients were included. Four studies evaluated the effects of low-dose unfractionated heparin (LDUH) compared placebo or untreated. No significant differences were observed, with the summary RR 0.661 (95% confidence interval (CI) 0.365-1.199; Z=1.36, P=0.173) for VTE. Only one RCT compared fixed-dose LDUH with adjusted-dose LDUH, which showed lower VTE incidence but higher bleeding incidence for adjusted dose. Nine trials have compared LDUH with low-molecular-weight heparin (LMWH). No significant differences were observed for VTE with the summary RR 1.633 (95% CI 0.822-3.243; Z=1.40, P=0.162). But major bleeding was lower with LMWH (summary RR=2.034, 95% CI 1.018-4.063; Z=2.01, P=0.044). Three studies compared different LMWHs, which included one for enoxaparin versus tinzaparin and two for enoxaparin versus dalteparin. No significant differences were observed with the summary RR 0.694 (95% CI 0.336-1.434; Z=0.99, P=0.324) for VTE. Three studies compared different dose of LMWH. No differences were observed.
CONCLUSION
Our meta-analysis showed that in patients with acute SCI, LDUH have no thromboprophylaxis effect compared with placebo or untreated; LMWH seems only can reduce bleeding incidence, but not prophylaxis thromboembolism compared with LDUH. Because of no good quality studies existed in this setting, well-designed RCTs are urgently needed.
Topics: Fibrinolytic Agents; Heparin; Humans; PubMed; Randomized Controlled Trials as Topic; Spinal Cord Injuries; Venous Thromboembolism
PubMed: 23689387
DOI: 10.1038/sc.2013.48 -
Prescrire International Apr 2013Patients with deep venous thrombosis are at a short-term risk of symptomatic or even life-threatening pulmonary embolism, and a long-term risk of post-thrombotic... (Comparative Study)
Comparative Study Review
Patients with deep venous thrombosis are at a short-term risk of symptomatic or even life-threatening pulmonary embolism, and a long-term risk of post-thrombotic syndrome, characterised by lower-limb pain, varicose veins, oedema, and sometimes skin ulcers. What is the best choice of initial antithrombotic therapy following deep venous thrombosis or pulmonary embolism, in terms of mortality and short-term and long-term complications? How do the harm-benefit balances of the different options compare? To answer these questions, we reviewed the available literature using the standard Prescrire methodology. Unfractionated heparin has documented efficacy in reducing mortality and recurrent thromboembolic events in patients with pulmonary embolism or symptomatic proximal (above-knee) deep venous thrombosis. The authors of a systematic review selected 23 trials of low-molecular-weight heparin (LMWH) versus adjusted-dose unfractionated heparin in a total of 9587 patients. Deaths, recurrences and major bleeds were less frequent with LMWH than with unfractionated heparin. The results of other meta-analyses are similar, but all are undermined by a probable publication bias and methodological flaws. Compared to unfractionated heparin, LMWHs have the advantage of fixed-dose administration, once or twice daily, by subcutaneous injection. All available LMWHs seem to have similar efficacy. Those with the longest experience of use are enoxaparin, dalteparin and nadroparin. The harm-benefit balances of fondaparinux and rivaroxaban do not appear more favourable than that of an LMWH followed by an adjusted-dose vitamin K antagonist. A meta-analysis included 12 trials comparing thrombolysis with anticoagulation alone in 700 patients with deep venous thrombosis. Adding a thrombolytic drug did not reduce mortality or the incidence of pulmonary embolism, whereas it increased the incidence of bleeding. A meta-analysis of 13 trials failed to show that adding a thrombolytic drug to initial anticoagulant therapy reduced mortality or recurrences after pulmonary embolism. In the 5 trials that included patients with massive pulmonary embolism, thrombolytic therapy appeared to reduce mortality by about one-half (6% versus 13%). This difference is noteworthy, even if it did not reach the usual threshold of statistical significance. The results of the 6 trials involving patients with deep venous thrombosis, and those of 2 trials and 8 cohort studies in patients with pulmonary embolism at low risk of complications, suggest that outpatient management is acceptable in some cases. Clinical practice guidelines largely agree on the use of LMWH or fondaparinux as initial therapy for most patients with deep venous thrombosis or pulmonary embolism. Unfractionated heparin is generally recommended for patients with renal failure. Thrombolysis is recommended for massive pulmonary embolism and, in some guidelines, for iliofemoral venous thrombosis. In practice, initial treatment of deep venous thrombosis and pulmonary embolism should be based on LMWH in patients without renal failure. Thrombolytic agents may be useful in case of massive pulmonary embolism, but more evaluation is needed. Bleeding and heparin thrombocytopenia are the main adverse effects of these treatments.
Topics: Anticoagulants; Heparin; Heparin, Low-Molecular-Weight; Humans; Practice Guidelines as Topic; Pulmonary Embolism; Secondary Prevention; Venous Thrombosis
PubMed: 23662321
DOI: No ID Found -
Pharmacotherapy Dec 2013Major orthopedic surgery is associated with a high risk of venous thromboembolism (VTE). Anticoagulants are recommended to prevent VTE, and recently an oral direct... (Comparative Study)
Comparative Study Meta-Analysis Review
The cost-effectiveness of oral direct factor Xa inhibitors compared with low-molecular-weight heparin for the prevention of venous thromboembolism prophylaxis in total hip or knee replacement surgery.
INTRODUCTION
Major orthopedic surgery is associated with a high risk of venous thromboembolism (VTE). Anticoagulants are recommended to prevent VTE, and recently an oral direct factor Xa inhibitor (FXaI) was approved for this indication. We compared the cost-effectiveness of FXaIs with low-molecular-weight heparin (LMWH) in patients undergoing total hip replacement (THR) or total knee replacement (TKR) surgery.
DESIGN
A decision-tree model was developed to compare the cost-effectiveness of oral direct FXaIs (rivaroxaban, apixaban, and edoxaban) to subcutaneous LMWHs (enoxaparin and dalteparin), with separate models for THR and TKR. The analysis was conducted over a 180-day postoperative time horizon from the U.S. Medicare perspective. The model was developed using TreeAge Pro 2011 (TreeAge Software Inc., Williamstown, MA, USA).
METHODS
Efficacy and safety data (probabilities of distal and proximal deep vein thrombosis, symptomatic pulmonary embolism, and major bleeding) were derived from a systematic review and meta-analysis of phase II and III clinical trials. Costs and quality-adjusted life-years (QALYs) are reported. One-way and probabilistic sensitivity analyses were performed to evaluate parameter uncertainty.
RESULTS
In the THR model, the average costs per patient for FXaIs and LMWHs were $18,762 and $18,897, respectively, and the QALYs were 0.938 and 0.932. In the TKR model, the average cost per patient for FXaIs and LMWHs were $18,804 and $18,991, respectively, and the QALYs were 0.935 and 0.931. In both models, FXaIs dominated LMWH (less costly and more efficacious). Neither model was sensitive to changes in any of the variables in the one-way sensitivity analyses. Probabilistic sensitivity analysis indicated that FXaIs were cost-effective in more than 99% of iterations in the THR population and in 98% of iterations in the TKR population assuming a willingness-to-pay threshold of $50,000/QALY.
CONCLUSION
Oral direct FXaIs may be an economically dominant strategy compared with LMWHs for VTE prophylaxis in patients undergoing either THR or TKR surgery.
Topics: Anticoagulants; Arthroplasty, Replacement, Hip; Arthroplasty, Replacement, Knee; Cost-Benefit Analysis; Decision Trees; Factor Xa Inhibitors; Heparin, Low-Molecular-Weight; Humans; Medicare; Models, Theoretical; Postoperative Complications; Quality-Adjusted Life Years; United States; Venous Thromboembolism
PubMed: 23625693
DOI: 10.1002/phar.1269 -
The American Journal of Medicine Aug 2011Post-thrombotic syndrome causes considerable morbidity. The Home-LITE study showed a lower incidence of post-thrombotic syndrome and venous ulcers after 3 months of... (Comparative Study)
Comparative Study Review
OBJECTIVE
Post-thrombotic syndrome causes considerable morbidity. The Home-LITE study showed a lower incidence of post-thrombotic syndrome and venous ulcers after 3 months of treating deep vein thrombosis with the low-molecular-weight heparin tinzaparin versus oral anticoagulation. This systematic review examined whether long-term treatment of deep vein thrombosis using low-molecular-weight heparin, rather than oral anticoagulation, reduces development of post-thrombotic syndrome.
METHODS
We identified 9 articles comparing treatment of deep vein thrombosis using long-term low-molecular-weight heparin with any comparator, which reported outcomes relevant to the post-thrombotic syndrome assessed ≥ 3 months post-deep vein thrombosis.
RESULTS
Pooled analysis of 2 studies yielded an 87% risk reduction with low-molecular-weight heparin in the incidence of venous ulcers at ≥ 3 months (P = .019). One study showed an overall odds ratio of 0.77 (P = .001) favoring low-molecular-weight heparin for the presence of 8 patient-reported post-thrombotic syndrome signs and symptoms. Pooled analysis of 5 studies showed a risk ratio for low-molecular-weight heparin versus oral anticoagulation of 0.66 (P < .0001) for complete recanalization of thrombosed veins.
CONCLUSION
These results support the lower incidence of post-thrombotic syndrome and venous ulcers observed in Home-LITE. Long-term treatment with low-molecular-weight heparin rather than oral anticoagulation after a deep vein thrombosis may reduce or prevent development of signs and symptoms associated with post-thrombotic syndrome. Post-thrombotic syndrome and associated acute ulcers may develop more rapidly after deep vein thrombosis than previously recognized.
Topics: Anticoagulants; Dalteparin; Drug Administration Schedule; Enoxaparin; Heparin, Low-Molecular-Weight; Humans; Incidence; Nadroparin; Postthrombotic Syndrome; Severity of Illness Index; Tinzaparin; Varicose Ulcer; Veins; Venous Thrombosis
PubMed: 21787905
DOI: 10.1016/j.amjmed.2011.02.033 -
The Cochrane Database of Systematic... Jun 2011Compared to patients without cancer, patients with cancer who receive anticoagulant treatment for venous thromboembolism are more likely to develop recurrent venous... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Compared to patients without cancer, patients with cancer who receive anticoagulant treatment for venous thromboembolism are more likely to develop recurrent venous thromboembolism (VTE).
OBJECTIVES
To compare the efficacy and safety of three types of parenteral anticoagulants for the initial treatment of VTE in patients with cancer.
SEARCH STRATEGY
A comprehensive search for studies of anticoagulation in cancer patients including a February 2010 electronic search of: the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and ISI Web of Science.
SELECTION CRITERIA
Randomized clinical trials (RCTs) comparing low molecular weight heparin (LMWH), unfractionated heparin (UFH), and fondaparinux in patients with cancer and objectively confirmed VTE.
DATA COLLECTION AND ANALYSIS
Using a standardized data form, data was extracted in duplicate on methodological quality, participants, interventions, and outcomes of interest that included mortality, recurrent VTE, major bleeding, minor bleeding, postphlebitic syndrome, quality of life, and thrombocytopenia.
MAIN RESULTS
Of 3986 identified citations, 16 RCTs were eligible: 13 compared LMWH to UFH, two compared fondaparinux to heparin, and one compared dalteparin to tinzaparin. Meta-analysis of 11 studies showed a statistically significant reduction in mortality at three months of follow up with LMWH compared with UFH (relative risk (RR) 0.71; 95% confidence interval (CI) 0.52 to 0.98). There was little change in the effect estimate after excluding studies of lower methodological quality (RR 0.72; 95% CI 0.52 to 1.00). A meta-analysis of three studies comparing LMWH with UFH showed no statistically significant reduction in VTE recurrence (RR 0.78; 95% CI 0.29 to 2.08). The overall quality of evidence was low for LMWH versus UFH due to imprecision and likely publication bias. There were no statistically significant differences between heparin and fondaparinux for the outcomes of death (RR 1.27; 95% CI 0.88 to 1.84), recurrent VTE (RR 0.95; 95% CI 0.57 to 1.60), major bleeding (RR 0.79; 95% CI 0.39 to1.63) or minor bleeding (RR 1.50; 95% CI 0.87 to 2.59). The one study comparing dalteparin to tinzaparin did not find a statistically significant difference in mortality (RR 0.86; 95% CI 0.43 to 1.73).
AUTHORS' CONCLUSIONS
LMWH is possibly superior to UFH in the initial treatment of VTE in patients with cancer. Additional trials focusing on patient important outcomes will further inform the questions addressed in this review.
Topics: Anticoagulants; Dalteparin; Fibrinolytic Agents; Fondaparinux; Heparin; Heparin, Low-Molecular-Weight; Humans; Neoplasms; Polysaccharides; Randomized Controlled Trials as Topic; Secondary Prevention; Venous Thromboembolism
PubMed: 21678360
DOI: 10.1002/14651858.CD006649.pub5 -
The Cochrane Database of Systematic... Apr 2011Compared to patients without cancer, patients with cancer who receive anticoagulant treatment for venous thromboembolism are more likely to develop recurrent venous... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Compared to patients without cancer, patients with cancer who receive anticoagulant treatment for venous thromboembolism are more likely to develop recurrent venous thromboembolism (VTE).
OBJECTIVES
To compare the efficacy and safety of three types of parenteral anticoagulants for the initial treatment of VTE in patients with cancer.
SEARCH STRATEGY
A comprehensive search for studies of anticoagulation in cancer patients including a February 2010 electronic search of: the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and ISI Web of Science.
SELECTION CRITERIA
Randomized clinical trials (RCTs) comparing low molecular weight heparin (LMWH), unfractionated heparin (UFH), and fondaparinux in patients with cancer and objectively confirmed VTE.
DATA COLLECTION AND ANALYSIS
Using a standardized data form, data was extracted in duplicate on methodological quality, participants, interventions, and outcomes of interest that included mortality, recurrent VTE, major bleeding, minor bleeding, postphlebitic syndrome, quality of life, and thrombocytopenia.
MAIN RESULTS
Of 3986 identified citations, 16 RCTs were eligible: 13 compared LMWH to UFH, two compared fondaparinux to heparin, and one compared dalteparin to tinzaparin. Meta-analysis of 11 studies showed a statistically significant reduction in mortality at three months of follow up with LMWH compared with UFH (relative risk (RR) 0.71; 95% confidence interval (CI) 0.52 to 0.98). There was little change in the effect estimate after excluding studies of lower methodological quality (RR 0.72; 95% CI 0.52 to 1.00). A meta-analysis of three studies comparing LMWH with UFH showed no statistically significant reduction in VTE recurrence (RR 0.78; 95% CI 0.29 to 2.08). The overall quality of evidence was low for LMWH versus UFH due to imprecision and likely publication bias. There were no statistically significant differences between heparin and fondaparinux for the outcomes of death (RR 1.27; 95% CI 0.88 to 1.84), recurrent VTE (RR 0.95; 95% CI 0.57 to 1.60), major bleeding (RR 0.79; 95% CI 0.39 to1.63) or minor bleeding (RR 1.50; 95% CI 0.87 to 2.59). The one study comparing dalteparin to tinzaparin did not find a statistically significant difference in mortality (RR 0.86; 95% CI 0.43 to 1.73).
AUTHORS' CONCLUSIONS
LMWH is possibly superior to UFH in the initial treatment of VTE in patients with cancer. Additional trials focusing on patient important outcomes will further inform the questions addressed in this review.
Topics: Anticoagulants; Dalteparin; Fibrinolytic Agents; Heparin; Heparin, Low-Molecular-Weight; Humans; Neoplasms; Polysaccharides; Randomized Controlled Trials as Topic; Secondary Prevention; Venous Thromboembolism
PubMed: 21491395
DOI: 10.1002/14651858.CD006649.pub4 -
The Cochrane Database of Systematic... Feb 2011Compared to patients without cancer, patients with cancer who receive anticoagulant treatment for venous thromboembolism are more likely to develop recurrent venous... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Compared to patients without cancer, patients with cancer who receive anticoagulant treatment for venous thromboembolism are more likely to develop recurrent venous thromboembolism (VTE).
OBJECTIVES
To compare the efficacy and safety of three types of parenteral anticoagulants for the initial treatment of VTE in patients with cancer.
SEARCH STRATEGY
A comprehensive search for studies of anticoagulation in cancer patients including a February 2010 electronic search of: the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and ISI Web of Science.
SELECTION CRITERIA
Randomized clinical trials (RCTs) comparing low molecular weight heparin (LMWH), unfractionated heparin (UFH), and fondaparinux in patients with cancer and objectively confirmed VTE.
DATA COLLECTION AND ANALYSIS
Using a standardized data form, data was extracted in duplicate on methodological quality, participants, interventions, and outcomes of interest that included mortality, recurrent VTE, major bleeding, minor bleeding, postphlebitic syndrome, quality of life, and thrombocytopenia.
MAIN RESULTS
Of 3986 identified citations, 16 RCTs were eligible: 13 compared LMWH to UFH, two compared fondaparinux to heparin, and one compared dalteparin to tinzaparin. Meta-analysis of 11 studies showed a statistically significant reduction in mortality at three months of follow up with LMWH compared with UFH (relative risk (RR) 0.71; 95% confidence interval (CI) 0.52 to 0.98). There was little change in the effect estimate after excluding studies of lower methodological quality (RR 0.72; 95% CI 0.52 to 1.00). A meta-analysis of three studies comparing LMWH with UFH showed no statistically significant reduction in VTE recurrence (RR 0.78; 95% CI 0.29 to 2.08). The overall quality of evidence was low for LMWH versus UFH due to imprecision and likely publication bias. There were no statistically significant differences between heparin and fondaparinux for the outcomes of death (RR 1.27; 95% CI 0.88 to 1.84), recurrent VTE (RR 0.95; 95% CI 0.57 to 1.60), major bleeding (RR 0.79; 95% CI 0.39 to1.63) or minor bleeding (RR 1.50; 95% CI 0.87 to 2.59). The one study comparing dalteparin to tinzaparin did not find a statistically significant difference in mortality (RR 0.86; 95% CI 0.43 to 1.73).
AUTHORS' CONCLUSIONS
LMWH is possibly superior to UFH in the initial treatment of VTE in patients with cancer. Additional trials focusing on patient important outcomes will further inform the questions addressed in this review.
Topics: Anticoagulants; Dalteparin; Fibrinolytic Agents; Fondaparinux; Heparin; Heparin, Low-Molecular-Weight; Humans; Neoplasms; Polysaccharides; Randomized Controlled Trials as Topic; Tinzaparin; Venous Thromboembolism
PubMed: 21328285
DOI: 10.1002/14651858.CD006649.pub3 -
PLoS Medicine Jun 2010Factor V Leiden (FVL) and prothrombin gene mutation (PGM) are common inherited thrombophilias. Retrospective studies variably suggest a link between maternal FVL/PGM and... (Meta-Analysis)
Meta-Analysis Review
The association of factor V leiden and prothrombin gene mutation and placenta-mediated pregnancy complications: a systematic review and meta-analysis of prospective cohort studies.
BACKGROUND
Factor V Leiden (FVL) and prothrombin gene mutation (PGM) are common inherited thrombophilias. Retrospective studies variably suggest a link between maternal FVL/PGM and placenta-mediated pregnancy complications including pregnancy loss, small for gestational age, pre-eclampsia and placental abruption. Prospective cohort studies provide a superior methodologic design but require larger sample sizes to detect important effects. We undertook a systematic review and a meta-analysis of prospective cohort studies to estimate the association of maternal FVL or PGM carrier status and placenta-mediated pregnancy complications.
METHODS AND FINDINGS
A comprehensive search strategy was run in Medline and Embase. Inclusion criteria were: (1) prospective cohort design; (2) clearly defined outcomes including one of the following: pregnancy loss, small for gestational age, pre-eclampsia or placental abruption; (3) maternal FVL or PGM carrier status; (4) sufficient data for calculation of odds ratios (ORs). We identified 322 titles, reviewed 30 articles for inclusion and exclusion criteria, and included ten studies in the meta-analysis. The odds of pregnancy loss in women with FVL (absolute risk 4.2%) was 52% higher (OR = 1.52, 95% confidence interval [CI] 1.06-2.19) as compared with women without FVL (absolute risk 3.2%). There was no significant association between FVL and pre-eclampsia (OR = 1.23, 95% CI 0.89-1.70) or between FVL and SGA (OR = 1.0, 95% CI 0.80-1.25). PGM was not associated with pre-eclampsia (OR = 1.25, 95% CI 0.79-1.99) or SGA (OR 1.25, 95% CI 0.92-1.70).
CONCLUSIONS
Women with FVL appear to be at a small absolute increased risk of late pregnancy loss. Women with FVL and PGM appear not to be at increased risk of pre-eclampsia or birth of SGA infants. Please see later in the article for the Editors' Summary.
Topics: Abortion, Spontaneous; Abruptio Placentae; Factor V; Female; Humans; Infant, Newborn; Infant, Small for Gestational Age; Mutation; Odds Ratio; Placenta; Pre-Eclampsia; Pregnancy; Pregnancy Complications, Hematologic; Prothrombin; Risk Factors; Stillbirth; Thrombophilia
PubMed: 20563311
DOI: 10.1371/journal.pmed.1000292 -
The Cochrane Database of Systematic... Apr 2008Cancer increases the risk of thromboembolic events and the risk of recurrent thromboembolic events while on anticoagulation. (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Cancer increases the risk of thromboembolic events and the risk of recurrent thromboembolic events while on anticoagulation.
OBJECTIVES
To compare the efficacy and safety of low molecular weight heparin (LMWH) and oral anticoagulants (vitamin K antagonist (VKA) and ximelagatran) for the long term treatment of venous thromboembolism (VTE) in patients with cancer.
SEARCH STRATEGY
A comprehensive search was undertaken including a January 2007 search of electronic databases; Cochrane Central Register of Controlled Trials (CENTRAL), (The Cochrane Library 2007, Issue 1). MEDLINE (1966 onwards; accessed via OVID), EMBASE (1980 onwards; accessed via OVID) and ISI the Web of Science. Hand search of the proceedings of the American Society of Clinical Oncology and of the American Society of Hematology. Checking of references of included studies, relevant papers and related systematic reviews. Use of "related article" feature in PubMed; and (5) search of ISI the Web of Science for papers citing landmark studies.
SELECTION CRITERIA
Randomized controlled trials (RCTs) comparing long term treatment with LMWH versus oral anticoagulants (VKA or ximelagatran) in patients with cancer and symptomatic objectively confirmed VTE.
DATA COLLECTION AND ANALYSIS
Using a standardized data form we extracted data on methodological quality, participants, interventions and outcomes of interest: survival, recurrent VTE, major bleeding, minor bleeding, thrombocytopenia and postphlebitic syndrome.
MAIN RESULTS
Of 3986 identified citations, eight RCTs were eligible and reported data for patients with cancer. Their overall methodological quality was moderate. Meta-analysis of six RCTs showed that LMWH, compared to VKA provided no statistically significant survival benefit (Hazard ratio (HR) = 0.96; 95% CI 0.81 to 1.14) but a statistically significant reduction in VTE (HR = 0.47; 95% (Confidence Interval (CI) = 0.32 to 0.71). There was no statistically significant difference between LMWH and VKA in bleeding outcomes (RR = 0.91; 95% CI = 0.64 to 1.31) or thrombocytopenia (RR = 1.02; 95% CI = 0.60 to 1.74). One RCT compared tinzaparin and dalteparin and showed no differences in the outcomes of interest. One RCT compared a six months extension of anticoagulation with 18 months Ximelagatran 24mg twice daily versus placebo. It showed a reduction in VTE (HR = 0.16; 95% CI 0.09 to 0.30) with no apparent effect on survival or bleeding.
AUTHORS' CONCLUSIONS
For the long term treatment of VTE in patients with cancer, LMWH compared to VKA reduces venous thromboembolic events but not death. The decision for a patient with cancer and VTE to start long term LMWH versus oral anticoagulation should balance the benefits and downsides and integrate the patient's values and preferences for the important outcomes and alternative management strategies.
Topics: Anticoagulants; Azetidines; Benzylamines; Heparin, Low-Molecular-Weight; Humans; Neoplasms; Randomized Controlled Trials as Topic; Venous Thromboembolism; Vitamin K
PubMed: 18425959
DOI: 10.1002/14651858.CD006650.pub2 -
The Cochrane Database of Systematic... Jan 2008Compared to patients without cancer, patients with cancer receiving anticoagulant treatment for venous thromboembolism are more likely to develop recurrent venous... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Compared to patients without cancer, patients with cancer receiving anticoagulant treatment for venous thromboembolism are more likely to develop recurrent venous thromboembolism (VTE).
OBJECTIVES
To compare the efficacy and safety of three types of anticoagulants (i.e. low molecular weight heparin (LMWH), unfractionated heparin (UFH), and fondaparinux) for the initial treatment of VTE in patients with cancer.
SEARCH STRATEGY
A comprehensive search for studies of anticoagulation in cancer patients including a January 2007 electronic search of : Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and ISI the Web of Science.
SELECTION CRITERIA
Randomized clinical trials (RCTs) comparing LMWH, UFH, and fondaparinux in patients with cancer and objectively confirmed VTE.
DATA COLLECTION AND ANALYSIS
Using a standardized data form data was extracted in duplicate on methodological quality, participants, interventions and outcomes of interest that included all cause mortality, recurrent VTE, major bleeding, minor bleeding, thrombocytopenia and postphlebitic syndrome.
MAIN RESULTS
Of 3986 identified citations, 26 RCTs including cancer patients as subgroups fulfilled the inclusion criteria. Cancer subgroup data was obtained for 15 of the 26 RCTs. Thirteen studies compared a LMWH to UFH while one study compared fondaparinux to UFH and one study compared dalteparin to tinzaparin. Meta-analysis of 11 studies showed a statistically significant mortality reduction in patients treated with LMWH compared with those treated with UFH (Relative risk (RR) = 0.71; 95% confidence interval (CI) 0.52 to 0.98). There was little change in the results after excluding studies of lower methodological quality (RR = 0.72; 95% CI 0.52 to 1.00). A meta-analysis of three studies comparing LMWH with UFH in reducing recurrent VTE was inconclusive (RR = 0.78; 95% CI 0.29 to 2.08). No data was available for bleeding outcomes, thrombocytopenia or postphlebitic syndrome. Compared to UFH, fondaparinux showed a non-statistically significant benefit for the outcome of death (RR = 0.52; 95% CI 0.26 to 1.05). The one study comparing dalteparin to tinzaparin showed a non-statistically significant mortality reduction with dalteparin (RR = 0.86; 95% CI 0.43 to 1.73).
AUTHORS' CONCLUSIONS
Based on the included trials, LMWH is likely to be superior to UFH in the initial treatment of VTE in patients with cancer. However, there is a need for more trials to better address this research question in cancer patients. Moreover, researchers should consider making the raw data of RCTs available for individual patient data meta-analyses.
Topics: Anticoagulants; Fondaparinux; Heparin; Heparin, Low-Molecular-Weight; Humans; Neoplasms; Polysaccharides; Randomized Controlled Trials as Topic; Venous Thromboembolism
PubMed: 18254108
DOI: 10.1002/14651858.CD006649.pub2