Long-term management of deep vein thrombosis.

A venous thromboembolic event may cause substantial long-term morbidity despite the best available treatment. Venous thromboembolism (VTE) recurs in approximately 30% of patients within eight years of the acute event, and a similar proportion develop post-thrombotic syndrome, imposing a notable clinical and financial burden. Conventional treatment of VTE comprises an initial 5-10 day course of intravenous unfractionated heparin (UFH), followed by oral anticoagulants for 3-6 months. Thrombolytic therapy, vena caval filters and surgical thrombectomy are reserved for patients with complications. Alternative approaches, including more intensive initial anticoagulation or extended secondary prevention, may improve long-term outcomes. Low-molecular-weight heparins (LMWHs) are at least as effective as UFH in acute therapy and are suitable for home treatment, offering the potential for cost reductions and improved patient convenience. Consequently, LMWHs are replacing UFH in initial treatment of VTE. The optimal duration of secondary VTE prophylaxis remains uncertain. Extended therapy with LMWH reduces the frequency of VTE recurrence, but routine use of prolonged therapy is not economically viable. Targeting extended therapy to patients at greatest risk of recurrence, for example, patients with identified congenital thrombophilia, would maximize cost-effectiveness. Comprehensive risk assessment models are now needed to stratify patients for primary VTE risk level, allowing appropriate targeting of prophylaxis, more intensive initial treatment or extended therapy for acute VTE.