Even after excluding patients with atrial fibrillation, the duration of anticoagulant treatment for patients with unprovoked venous thromboembolism (VTE) and patients with transient risk factors often exceeded 1 year, according to a study published in Thrombosis Research.

In a large prospective cohort study, lead author Dr. Walter Ageno of the University of Insubria, Varese, Italy, and his associates examined 6,944 patients with a first episode of VTE. In this sample, 55% of patients with unprovoked events, 42% of patients with a transient risk factor, and 43% of patients with cancer received anticoagulant treatment for more than 12 months. The American College of Chest Physicians guideline recommends a 3-month treatment duration for patients with VTE secondary to transient risk factors. Pulmonary embolism at presentation, VTE recurrence while on treatment, chronic heart failure, and advanced age were independently associated with treatment for more than 12 months. Patients who died during the first year of treatment were excluded from the results.

Although clinicians tend to base their VTE treatment decisions on individual risk stratification, “this approach may expose a substantial proportion of patients, in particular those with VTE secondary to transient risk factors, to a possibly unnecessary risk of bleeding,” the investigators concluded. Read the full article here: Thrombosis Research 2015.