Incidence of arterial embolism in patients on treatment with old and new anticoagulants for venous thromboembolism

The separate nature of venous and arterial thrombotic disorders has recently been challenged. Patients with venous thromboembolism (VTE) have an increased risk of subsequent symptomatic arterial cardiovascular events, the risk being higher in those with unexplained episodes. Among the implications of this association, there is the potential for old and new antithrombotic drugs to impact on the development of both venous and arterial cardiovascular events. According to the results of recent studies, aspirin in low doses, when administered for the long-term management of patients with unprovoked VTE, reduces by approximately 35% the risk of recurrent VTE while offering a considerable protection against the development of arterial cardiovascular events. By contrast, there is no room to expect a reduction in the risk of subsequent arterial cardiovascular events in patients treated with vitamin K antagonists (VKA) in comparison to patients in whom VKAs are discontinued. According to the results from recent randomized clinical trials, the likelihood of arterial cardiovascular events in patients on the novel direct factor Xa inhibitors is unlikely to differ from that of patients receiving conventional anticoagulation. As dabigatran has been associated with a slight increase in the risk of myocardial infarction over warfarin, its use should be discouraged in patients with coronary heart disease. The long-term use of low-dose apixaban beyond the first months in patients with unprovoked VTE may decrease the long-term risk of arterial, as well as venous, thrombotic events.