The recent clinical trials on use of the novel direct oral anticoagulants in patients with venous thromboembolism: a review

Venous thromboembolism (VTE), encompassing deep vein thrombosis and pulmonary embolism, requires an immediate anticoagulation, that has been carried out so far by administering a parenteral anticoagulant drug (heparin or derivatives) overlapped with an oral vitamin K antagonist (VKA), more often warfarin. Several new direct oral anticoagulants (DOACs), with a mechanism of action completely different than VKA, have been developed in recent years. Recent clinical trials have investigated their use in VTE patients showing results at least equal for efficacy and safety, and sometime even better, as the standard anticoagulant treatment. There are differences in the design of the trials. In two cases the involved DOAC was administered immediately after VTE diagnosis as a single drug treatment (rivaroxaban and apixaban), whereas in the other trials (involving dabigatran and edoxaban) the DOAC was administered after an initial course of approximately 7 days with heparin or derivatives. Some clinical trials have also investigated the use of DOACs for extended anticoagulant treatment after the acute phase. Aim of this article is to review the results of the currently available clinical trials that have compared the use of DOACs versus the standard of care in patients with VTE.