Anticoagulation therapy is mandatory in patients with pulmonary embolism to prevent significant morbidity and mortality. The mainstay of therapy has been vitamin-K antagonist therapy bridged with parenteral anticoagulants. The recent approval of new oral anticoagulants (NOACs: apixaban, dabigatran, and rivaroxaban) has generated significant interest in their role in managing venous thromboembolism, especially pulmonary embolism due to their improved pharmacokinetic and pharmacodynamic profiles, predictable anticoagulant response, and lack of required efficacy monitoring. This paper addresses the available literature, on-going clinical trials, highlights critical points, and discusses potential advantages and disadvantages of the new oral anticoagulants in patients with pulmonary embolism. 1. Introduction Pulmonary embolism (PE) is a common, potentially fatal disease with an annual incidence of approximately 70 cases per 100？000 people [1, 2]. Patients generally require hospitalization and recurrence is common [3]. In addition to significant morbidity and mortality, treatment costs associated with thrombosis and the arising postthrombotic syndromes are staggering, with costs exceeding 500 million dollars annually in the United States [1, 4, 5]. The mainstay of treatment for the past fifty years has been warfarin therapy, overlapped with a parenteral anticoagulant until the vitamin K antagonist (VKA) is fully therapeutic [2, 5]. While highly effective at reducing morbidity and mortality associated with PE, VKA therapy poses challenges, including variability in drug response, patient compliance, and drug-drug, drug-disease, and drug-diet interactions [6–9]. Great interest has been generated regarding the recently marketed new oral anticoagulants (NOACs) and their potential role as alternative anticoagulant therapies. 2. Risk Assessment in Pulmonary Embolism Pulmonary embolism is a serious and potentially fatal complication of a venous thrombotic event (VTE). Despite clinical trials yielding similar estimates for safety and efficacy in overall treatment when comparing deep vein thrombosis (DVT) and PE, patients with PE incur additional risks not seen in patients with DVT alone. The impact of PE on mortality is striking, with significant increases in the risk of death at both 30 and 90 days after event [10]. In addition to increasing mortality, PE also has significant impact on morbidity. Cardiorespiratory impairment, including pulmonary hypertension, can result in chronic and irreversible health concerns. Additionally, recurrent episodes of either VTE or PE
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