Purpose: The purpose of this study is to compare the rates of recurrent VTE among cancer patients treated with parenteral agents to the oral anticoagulants.
Methods: This single-center study was a retrospective chart review of cancer patients with recurrent VTE between January 1, 2009 and December 31, 2014. The primary outcome of the study is the rate of recurrent VTE in patients who received a parenteral anticoagulant (enoxaparin, dalteparin, fondaparinux) versus those who received oral anticoagulants (warfarin and rivaroxaban). Other outcomes investigated include risk factors associated with recurrent VTE events and influence of third-party payer on anticoagulant selection.
Results: Four hundred fifty-seven patients met inclusion criteria (178 in the oral anticoagulant group and 279 in the parenteral anticoagulant group). Patients with Medicare were more likely to have received an oral anticoagulant (P = 0.003) and patients with private insurance were more likely to have received a parenteral anticoagulant (P = 0.004). There were 23 recurrent VTE events, 12 events (6.7 %) in the oral anticoagulant group and 11 events (3.94 %) in the parenteral group (P = 0.182). The only significant risk factor noted to increase risk of recurrent VTE was the presence of an IVC filter (adjusted OR 4.38, 95 % CI 1.67-11.53, P = 0.003).
Conclusions: While there is no statistical difference in VTE events between groups, the oral anticoagulant group numerically had a higher rate. Important associations were found to have an influence on anticoagulant selection and risk of recurrent VTE. These factors must be incorporated into decision making when treating cancer patients with VTE.
Keywords: Anticoagulation management; Cancer-associated venous thromboembolism; Low molecular weight heparin; Third-party payer; Warfarin.