Trial of the Effect of Low-Molecular-Weight Heparin (LMWH) Versus Warfarin on Mortality in the Long-Term Treatment of Proximal Deep Vein Thrombosis (DVT) (Main LITE Study)

The accepted treatment for acute deep vein thrombosis (DVT) is initial continuous intravenous heparin followed by long-term oral anticoagulant therapy. Improvements in the methods of clinical trials and the use of accurate objective tests to detect venous thromboembolism have made it possible to perform a series of randomized trials to evaluate various treatments of venous thromboembolism.

The specific objectives of the Main LITE Study are:

• to determine if low-molecular-weight heparin, given subcutaneously once daily without laboratory monitoring, is more effective than adjusted oral warfarin sodium in the reduction of mortality rate.
• to determine if such a low-molecular-weight heparin therapy is more cost-effective than present standard care methods.
• to determine the incidence of Factor V Leiden and Prothrombin 20210A mutant genetic abnormalities.

Inclusion criteria

• Patients having a first or recurrent episode of acute proximal vein thrombosis

Exclusion criteria

• Presence of familial bleeding diathesis or presence of active bleeding contraindicating anticoagulant therapy
• Receiving therapeutic heparin or therapeutic low-molecular-weight heparin for more than 48 hours or have already been on warfarin for more than 2 days for the treatment of proximal deep vein thrombosis
• Receiving long-term warfarin treatment
• Females who are pregnant
• Known allergy to heparin, warfarin sodium, or bisulfites
• History of heparin-associated thrombocytopenia
• Severe malignant hypertension
• Hepatic encephalopathy
• Severe renal failure
• Inability to attend follow-up due to geographic inaccessibility
• Inability or refusal to give informed consent
• Recent neurological or opthalmic surgery (within the previous 14 days)
• Pulmonary embolism requiring thrombolytic therapy, surgical thrombectomy, or vena cava interruption
• Life expectancy of less than 3 months
• Taking ASA prior to randomization and unable to discontinue this medication during the 84 day study treatment period