Prevention of venous thromboembolism in acutely ill medical patients after the results of recent trials with the new oral anticoagulants.

Venous thromboembolism (VTE) is a common potentially life-threatening complication in acutely ill medical patients; over 70 % of the fatal episodes of pulmonary embolism during hospitalization occur in non-surgical patients. In the absence of thromboprophylaxis, the incidence of venographically detected deep vein thrombosis is about 15 % in medical patients. Several trials and meta-analyses have clearly demonstrated the prophylactic role of unfractionated heparin, low molecular weight heparin and fondaparinux. Although over the past few years the knowledge of epidemiology, clinical features and prophylaxis in medical patients has significantly improved, there remain a number of controversial areas that require further investigation. Newer VTE risk assessment models have been proposed to select high risk hospitalized medical patients, but they still require external validation; scarce data are available to stratify patients to identify their individual bleeding risk. The optimal duration of thromboprophylaxis in medical patients is still a matter of debate; currently, extended prophylaxis after discharge is not recommended, but it may be required for subgroup of patients with persistently high VTE risk and a negligible risk of bleeding. Based on the results of recent studies, the new oral anticoagulants appear to have a very limited role, if any. However, a better risk stratification of patients who have a persistently increased risk of VTE is warranted to improve the risk to benefit profile of any anticoagulant drug to be used in this setting.