Chapter 112. Venous Thrombosis (Part 6) Table 111-3 Long- Term Treatment with Vitamin K Antagonists for Deep Vein Thrombosis (DVT) and Pulmonary Embolism (PE) Patient Categories Duration, months Comments First episode of DVT or PE secondary to a transie nt (reversible) risk factor 3 Recommendation applies to both proximal and calf vein thrombosis First episode of idiopathic DVT or PE 6–12 Continuation of anticoagulant therapy after 6– 12 months may be considered First episode of DVT 6–12 Continuation of or PE with a document ed thrombophilic abnormality anticoagulant therapy after 6– 12 months may be considered First episode of DVT or PE with documented antiphospholipid or two or more thrombophilic abnormalities 12 Continuation of anticoagulant therapy aft er 12 months may be considered The preferred intensity of VKA treatment for DVT is an INR between 2 and 3. Higher intensities are not more effective, whereas lower intensities are less effective with a similar bleeding risk. Although VKAs are generally used for long- term treatment, LMWH is preferred in patients with DVT and concomitant cancer. This treatment is associated with a lower risk of recurrent thrombosis than VKA and a similar risk of bleeding. The role of thrombolytic therapy as well as surgical removal of the thrombus in the initial treatment of DVT is controversial; the current recommendations are to refrain from their use with the single exception of patients with massive, recent ileofemoral DVT at risk of limb gangrene. Patients with DVT are at risk of developing the postthrombotic syndrome in the first years after the initial episode. This syndrome can range from mild, with some swelling and pain at the end of the day, to severe, with massive swelling and skin ulceration. Graduated elastic compression stockings to the knee with an ankle pressure of 30–40 mmHg fitted in the first weeks after the initial thrombosis and worn for 2 years reduce the risk of the postthrombotic syndrome by ~50%. As a result of the introduction of LMWH for the initial treatment of DVT, most patients with DVT can be treated at home either entirely or after a short hospital stay. The LMWH can be self-injected or given by family members or visiting nurses. Pulmonary Embolism The initial treatment with LMWH followed by a VKA for patients with PE is identical to that for patients with DVT. The intensity and duration of VKA treatment is also no different (Table 111-3). An alternative for LMWH is unfractionated heparin, which is still often used. The main disadvantage of unfractionated heparin is the need for continuous IV infusion and the requirement of frequent laboratory monitoring and dose adjustments. In contrast, LMWH can be given in fixed doses adjusted only for body weight. Another alternative for the initial LMWH therapy is fondaparinux, which can be given as a 2.5-mg once-a- day SC injection, without laboratory monitoring. The treatment with LWMH or fondaparinux followed by VKA is indicated for PE patients who are hemodynamically stable—the great majority of patients. However, for those patients with PE who are hemodynamically unstable (usually defined as a systolic blood pressure <90–100 mmHg), a course of thrombolytic therapy should be considered. When no contraindications for thrombolysis (such as recent surgery or a bleeding diathesis) exist, this therapy reduces the short-term risk of recurrent PE or death by ~50% as compared to heparin. Although streptokinase and urokinase have been used in patients with PE, the most widely applied regimen is recombinant tissue plasminogen activator r(tPA) (bolus of 10 mg IV, followed by 90 mg in 2 h). A controversial area is the best therapy for PE patients who are hemodynamically stable, but who have echocardiographic evidence of right ventricular dysfunction (usually defined as paradoxical interventricular septal motion and right ventricular dilatation and impaired systolic function). Although these patients have a higher mortality risk compared to patients without right ventricular dysfunction, it is unclear whether more aggressive therapy (with thrombolytic therapy or catheter removal of thrombus) is beneficial in terms of mortality, recurrent PE, and major hemorrhage. Another area of controversy is vena caval interruption, usually with caval filters. The current recommendation is that a filter, preferably removable, should be considered only for patients with a contraindication for anticoagulant therapy, as well as in those with recurrent PE despite adequate treatment. Further Readings Colman RW et al (eds): Hemostasis and Thr ombosis: Basic Principles and Clinical Practice, 5th ed. Philadelphia, Lippincott Williams & Wilkins, 2006 Prandoni P: Links between arterial and venous disease. J Intern Med 262:341, 2007 [PMID: 17697155] Rosendaal FR: Venous thrombosis, a multicausal disease. Lancet 353:1167, 1999 [PMID: 10209995] The Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy. Chest 126(3 Suppl):167S, 2004 . Chapter 112. Venous Thrombosis (Part 6) Table 111-3 Long- Term Treatment with Vitamin K Antagonists for Deep Vein Thrombosis (DVT) and Pulmonary Embolism. Wilkins, 2006 Prandoni P: Links between arterial and venous disease. J Intern Med 262:341, 2007 [PMID: 17697155] Rosendaal FR: Venous thrombosis, a multicausal disease. Lancet 353:1167, 1999. Continuation of or PE with a document ed thrombophilic abnormality anticoagulant therapy after 6– 12 months may be considered First episode of DVT or PE with documented antiphospholipid