Clinical experience with the new oral anticoagulants for treatment of venous thromboembolism

Abstract

Four non-vitamin K antagonist oral anticoagulants, apixaban, dabigatran, edoxaban, and rivaroxaban, have been evaluated in phase III clinical trials for the treatment of acute venous thromboembolism, and all except edoxaban have also been studied for extended secondary prophylaxis after venous thromboembolism. Rivaroxaban, and recently also dabigatran, has been approved for this indication, and it is therefore timely to review the characteristics, efficacy, and safety of these drugs with emphasis on patients with venous thromboembolism. This review focuses on the clinical results from the phase III trials, separately for each of the drugs as compared with vitamin K antagonists. We also address the results from meta-analyses that were published recently. Finally, the results in some special groups of interest-renal impairment, elderly patients, and patients with cancer-are reviewed, although they only comprised small minorities of the study populations. All 4 drugs demonstrated noninferiority against vitamin K antagonists in the acute treatment and clear superiority against placebo in the extended treatment (not performed with edoxaban). The risk of bleeding was generally lower with non-vitamin K antagonist oral anticoagulants, and the reduction of risk of intracranial hemorrhage seems to mirror the experience from atrial fibrillation trials. In conclusion, during the past 30 years we have moved from a week of hospitalization and intravenous heparin therapy, via low-molecular-weight heparin injections subcutaneously and early discharge from the hospital, to the possibility of only oral outpatient therapy without coagulation monitoring, yet safe for patients with acute venous thromboembolism.

Keywords: hemorrhage; pulmonary embolism; recurrence; venous thrombosis.