For how long should the treatment with vitamin K antagonists be maintained?

Studies have shown that in most patients with venous thromboembolism (VTE), continuation of treatment with vitamin K antagonists for up to 27 months significantly reduces the probability of recurrence. Likewise, prolongation of oral anticoagulation beyond 6 months is believed to be of benefit in patients with certain forms of hereditary thrombophilia. Very prolonged periods of treatment with vitamin K antagonists at standard doses, although conferring benefit regarding the risk of recurrence of VTE, are associated with an increased incidence of major bleeds and require intensive monitoring. Use of a lower intensity of anticoagulation may reduce these negative aspects and enable anticoagulation to be carried out for longer.