A venous thromboembolic event may cause substantial long-term morbidity des
pite the best available treatment. Venous thromboembolism (VTE) recurs in a
pproximately 30% of patients within eight years of the acute event, and a s
imilar proportion develop postthrombotic syndrome, imposing a notable clini
cal and financial burden. Conventional treatment of VTE comprises an initia
l 5-10 day course of intravenous unfractionated heparin (UFH), followed by
oral anticoagulants for 3-6 months. Thrombolytic therapy, vena caval filter
s and surgical thrombectomy are reserved for patients with complications. A
lternative approaches, including more intensive initial anticoagulation or
extended secondary prevention, may improve long-term outcomes. Low-molecula
r-weight heparins (LMWHs) are at least as effective as UFH in acute therapy
and are suitable for home treatment, offering the potential for cost reduc
tions and improved patient convenience. Consequently, LMWHs are replacing U
FH in initial treatment of VTE. The optimal duration of secondary VTE proph
ylaxis 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 recurre
nce, for example, patients with identified congenital thrombophilia, would
maximize cost-effectiveness. Comprehensive risk assessment models are now n
eeded to stratify patients for primary VTE risk level, allowing appropriate
targeting of prophylaxis, more intensive initial treatment or extended the
rapy for acute VTE. (C) Lippincott Williams & Wilkins.