Guidelines for managing VTE (AAFP, ACP)

Clinical Question

What are the effective approaches to managing patients with venous thromboembolic events?

Bottom Line

Both unfractionated heparin or low-molecular-weight heparin (LMWH) are appropriate for the initial treatment of pulmonary embolism, however these guidelines suggest starting with LMWH whenever possible. Patients with deep vein thrombosis, and possibly pulmonary embolism, can be managed safely and cost-effectively as outpatients under the right circumstances. Use compression stockings for at least 1 year to prevent post-thrombotic syndrome. Maintain anticoagulation for 3 months to 6 months in patients with first-time venous thromboembolic events (VTE) or those with VTE due to transient risk factors. Patients with recurrent VTE should be treated for more than 12 months. LMWH and vitamin K antagonists have comparable effectiveness for the long-term treatment of VTE and may be preferable for patients with cancer. (LOE = 1a)


Snow V, Qaseem A, Barry P, et al, for the Joint American College of Physicians/American Academy of Family Physicians Panel on Deep Venous Thrombosis/Pulmonary Embolism. Management of venous thromboembolism: a clinical practice guideline from the American College of Physicians and the American Academy of Family Physicians. Ann Fam Med 2007;5:74-80.  [PMID:17261867]

Study Design

Practice guideline




Various (guideline)


This guideline was based on a systematic review performed by the Agency for Healthcare Research and Quality Evidence-Based Practice Centers. The guideline is aimed at any clinician caring for patients with VTE. There is an accompanying guideline on diagnosing VTE. The recommendations were derived largely from high-quality randomized controlled trials. The authors found 16 systematic reviews of clinical trials comparing LMWH and unfractionated heparin. No studies demonstrated unfractionated heparin to be more effective than LMWH, and patients treated with LMWH had fewer bleeding complications. Nine of these reviews reported that patients treated with LMWH had a lower mortality rate during the 3 months to 6 months after treatment than those treated with unfractionated heparin. The authors also found consistent evidence (from randomized controlled trials and cohort studies) that outpatient treatment of VTE with LMWH is cost-saving and at least as safe as inpatient treatment among highly selected patients. These studies used very well-developed educational and home care infrastructures as the foundation for managing these patients. The authors found 2 randomized controlled trials of compression stockings started within 1 month of diagnosis. Both trials found that the compression stockings reduced the incidence and severity of post-thrombotic syndrome. They found 11 observational studies of VTE in pregnancy and concluded that the evidence was insufficient to make any recommendations. Numerous trials have evaluated the duration and intensity of treatment. For patients with VTE due to transient risk factors (eg, recent immobilization, surgery, and so forth), treatment with warfarin (Coumadin) should last 3 months to 6 months with a target international normalized ratio of 2 to 3. Patients with a second VTE should be treated for at least 1 year. The authors found insufficient data to make recommendations on the use of vena cava filters and catheter-directed thrombolysis.