Extended Venous Thromboembolism Prophylaxis in Medically Ill Patients.

Prophylaxis for venous thromboembolism (VTE) in hospitalized acutely ill medical patients is a well-established practice. Despite the increased use of inpatient prophylaxis, the duration of hospitalization is typically shorter than the duration of VTE prophylaxis provided in clinical trials. In addition, VTE events after hospitalization are not unusual, with most events occurring within 30 days of hospital discharge. Therefore, the 30-day time period postdischarge has been identified as a stage in which patients are still at high risk of developing VTE. Attempts to provide extended prophylaxis with enoxaparin, rivaroxaban, or apixaban in patients with acute medical illness have been met with mixed results. Although some of these agents have reduced the incidence of VTE with extended prophylaxis, all of these agents have also demonstrated a significant increase in major bleeding that seems to offset any potential benefit. A recent trial of a new direct factor Xa inhibitor, betrixaban, demonstrated a reduction in VTE events with extended prophylaxis without significantly increasing the risk of major bleeding. Understanding appropriate patient selection, dosing, and outcomes associated with betrixaban will be important to potentially reducing the continued risk of VTE in patients with acute medical illness.