Randomized Controlled Trial of Anticoagulation vs. Placebo for a First Symptomatic Isolated Distal Deep-vein Thrombosis (IDDVT)

Inclusion Criteria: * All outpatients with an acute, symptomatic, distal DVT will be included in the study, provided they correspond to the following diagnostic and exclusion criteria, and they have signed an informed consent form. Exclusion Criteria: * Age less than 18 years * Previously objectively diagnosed DVT or PE * Distal DVT involving the tibioperoneal trunk (i.e. calf trifurcation) * Clinically suspected pulmonary embolism * Active cancer, receiving cancer treatment or cancer considered cured for \<6 months * Ipsilateral or contralateral proximal DVT * Indication for long-term anticoagulation (e.g. atrial fibrillation, mechanical heart valve...) * Pregnancy * Thrombocytopenia (platelet count \< 100 g/l) * Impaired renal function (serum creatinine \> 180 micromol/l or clearance to creatinine less than 30 ml/min) * Known hypersensitivity to heparin * Presence of an active bleeding or a pathology susceptible of bleeding in presence of anticoagulation (gastric ulcer, cerebral malignant disease...) * Treatment with daily NSAIDs (aspirin ≤160 mg/day permitted) * Body weight \>115 kg or \<40 kg * Treatment with therapeutic doses of anticoagulants for \>2 days, corresponding to: 2 injections of LMWH if once daily therapeutic LMWH used; 3 injections of LMWH if twice-daily therapeutic LMWH used; 1 dose of oral vitamin K antagonist (e.g. warfarin) * Ongoing requirement for prophylactic dose thromboprophylaxis (e.g. acute post-op patient receiving thromboprophylaxis) * Enroll…