confidence interval [CI], 0.26-0.42) and pulmonary embolism(RR,0.64;95%CI,0.50-0.82),aswasLMWH(RR, 0.56; 95% CI, 0.45-0.70; and RR, 0.37; 95% CI, 0.210.64,respectively).AUFHdosageof5000U3timesdaily was more effective in preventing DVT than a UFH dosage of 5000 U twice daily when compared with the control (RR, 0.27; 95% CI, 0.20-0.36; vs RR, 0.52; 95% CI, 0.28-0.96). Neither UFH nor LMWH reduced mortality. When directly compared with UFH, LMWH was associatedwithalowerriskofDVT(RR,0.68;95%CI,0.520.88) and injection site hematoma (RR, 0.47; 95% CI, 0.36-0.62), but no difference was seen between the 2 agents in the risk of bleeding or thrombocytopenia. Conclusions: Both UFH and LMWH reduce venous thromboembolicriskinhospitalizedmedicalpatients,but neither agent alters mortality. When directly compared, LMWH is more effective in preventing DVT.

https://jamanetwork.com/journals/jamainternalmedicine/articlepdf/412879/ioi70078_1476_1486.pdf

Does thrombolytic treatment modify the prognosis of pulmonary embolism

Pharmacological Venous Thromboembolism Prophylaxis in Hospitalized Medical Patients A Meta-analysis of Randomized Controlled Trials

Background and Purpose—Low-molecular-weight heparins and heparinoids (LMWHs) are superior to unfractionated heparin in the prevention and treatment of venous thromboembolism and acute coronary synd...

Low-Molecular-Weight Heparins and Heparinoids in Acute Ischemic Stroke: A Meta-Analysis of Randomized Controlled Trials

Background
Low-molecular-weight heparins and heparinoids are anticoagulants that may be associated with lower risks of haemorrhage and more powerful antithrombotic effects than standard unfractionated heparin. This is an updated version of the original Cochrane review first published in Issue 1, 1995 and previously updated in Issue 2, 2005.

Objectives
To compare the effects of low-molecular-weight heparins or heparinoids with those of unfractionated heparin in people with acute, confirmed or presumed, ischaemic stroke.

Search methods
We searched the Cochrane Stroke Group Trials Register (last searched June 2007). In addition we searched the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 2, 2007), MEDLINE (1966 to June 2007) and EMBASE (1980 to June 2007). For previous versions of this review we searched MedStrategy (1995) and also contacted pharmaceutical companies.

Selection criteria
Randomised trials comparing heparinoids or low-molecular-weight heparins with standard unfractionated heparin in people with acute ischaemic stroke. We only included trials where treatment was started within 14 days of stroke onset.

Data collection and analysis
Two review authors independently selected studies for inclusion, assessed trial quality and extracted the data.

Main results
Nine trials involving 3137 people were included. Four trials compared a heparinoid (danaparoid), four trials compared low-molecular-weight heparin (enoxaparin or certoparin), and one trial compared an unspecified low-molecular-weight heparin with standard unfractionated heparin. Allocation to low-molecular-weight heparin or heparinoid was associated with a significant reduction in the odds of deep vein thrombosis compared with standard unfractionated heparin (odds ratio (OR) 0.55, 95% confidence interval (CI) 0.44 to 0.70). However, the number of more major events (pulmonary embolism, death, intracranial or extracranial haemorrhage) was too small to provide a reliable estimate of the benefits and risks of low-molecular-weight heparins or heparinoids compared with standard unfractionated heparin for these, arguably more important, outcomes. Insufficient information was available to assess effects on recurrent stroke or functional outcome.

Authors' conclusions
Since the last version of this review none of the three new relevant studies with 2397 participants have provided additional information to change the conclusions. Treatment with a low-molecular-weight heparin or heparinoid after acute ischaemic stroke appears to decrease the occurrence of deep vein thrombosis compared with standard unfractionated heparin, but there are too few data to provide reliable information on their effects on other important outcomes, including death and intracranial haemorrhage.

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

We performed a systematic review of the literature on venous thromboembolism (VTE) prophylaxis following cerebral infarct (CI) and haemorrhagic stroke. MEDLINE, Cochrane, LILACS and SciELO databases were scanned, and the Abstracts from Brazilian, American and European Neurology and Stroke Congresses were scrutinized for clinical trials. Moreover, the reference lists of articles and reviews were searched. A pooled analysis of two large studies with aspirin was made. Both unfractionated heparin and low molecular weight heparins/heparinoids (LMWH) are partially effective for VTE prophylaxis after CI, and should be routinely used in patients with motor deficit and reduced mobility and no contraindications. Reduction of deep venous thrombosis is better established than the effect over pulmonary embolism or mortality. Some evidence points to a greater efficacy of LMWH. The available evidence does not support the use of mechanical methods or dextran. Aspirin may have a mild protective effect. Low-dose Warfarin might be useful in the rehabilitation setting. Strict recommendations cannot be made in patients with haemorrhagic stroke but intermittent pneumatic compression merits further study. There are important limitations of current VTE preventive strategies following stroke. Additional studies on the combination of methods after CI and of low doses of anticoagulants following cerebral haemorrhage are urgently needed.

Prevention of deep venous thrombosis and pulmonary embolism following stroke: a systematic review of published articles.

Pulmonary thromboembolism is commonly misdiagnosed and is associated with significant morbidity and mortality both in the early and late stages. A major cause of late morbidity is chronic pulmonary hypertension. Although the incidence of chronic thromboembolic pulmonary hypertension is unknown, there is anatomic and physiologic evidence that it is responsible for a significant degree of the late morbidity and mortality following acute pulmonary embolism. In the absence of underlying cardiopulmonary disease, pulmonary artery pressure is a useful indicator of the severity of acute pulmonary embolism and of the patient's prognosis. Thrombolytic agents accelerate the lysis of the thromboemboli, offer an excellent alternative to emergency embolectomy, and are likely to decrease the incidence of chronic pulmonary hypertension. All currently available agents have been shown to be effective and have similar bleeding-complication profiles. In this review, we discuss the natural history and pathophysiology of pulmonary thromboembolic disease, as well as applications of thrombolytic therapy in the treatment of acute pulmonary embolism.

Does thrombolytic treatment modify the prognosis of pulmonary embolism

Citations

Pharmacological Venous Thromboembolism Prophylaxis in Hospitalized Medical Patients A Meta-analysis of Randomized Controlled Trials

Low-Molecular-Weight Heparins and Heparinoids in Acute Ischemic Stroke: A Meta-Analysis of Randomized Controlled Trials

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

Prevention of deep venous thrombosis and pulmonary embolism following stroke: a systematic review of published articles.

Indications for thrombolytic therapy in acute pulmonary embolism.