Study objective: To compare hospital length of stay (LOS) and hospital treatment costs in low-risk patients with pulmonary embolism (PE) anticoagulated with rivaroxaban or heparin bridging to warfarin therapy.
Design: Retrospective review of electronic health records and hospital billing records.
Setting: Large, teaching hospital in the northeastern United States.
Patients: One hundred ninety adults with objectively confirmed acute PE presenting to the emergency department between November 1, 2012, and May, 12, 2015, who were classified as low risk of early mortality and received anticoagulation with either rivaroxaban or heparin (i.e., unfractionated heparin or low-molecular-weight heparin) bridging to warfarin therapy were included in the analysis. Patients were identified as low risk by at least one of the following prediction rules: simplified Pulmonary Embolism Severity Index (sPESI; 115 patients), Hestia criteria (87 patients), or In-hospital Mortality for Pulmonary Embolism using Claims Data (IMPACT; 108 patients); these were not mutually exclusive, as patients could be classified as low risk by more than one risk stratification tool.
Measurements and main results: We divided low-risk patients identified by each prediction rule into two cohorts: those receiving rivaroxaban (allowing ≤ 2 days of prior heparin use) or heparin bridging to warfarin therapy. The primary end points for this study were LOS (number of days from the patient's arrival at our institution until discharge) and total hospital treatment costs (our institution's actual costs to provide treatment) for the index PE hospital encounter. Using multivariable generalized linear model regression (gamma-distributed error and log-link), we estimated differences in LOS and hospital costs (in 2015 U.S. dollars) between the two cohorts after covariate adjustment. Rivaroxaban was associated with significantly shorter adjusted LOS (range -2.1 to -4.3 days) and significantly lower index hospital costs (range -$3835 to -$7094) versus heparin bridging to warfarin, regardless of the prediction rule used to identify low-risk patients.
Conclusion: Among low-risk PE patients identified by using sPESI, Hestia or IMPACT, rivaroxaban was associated with significantly shorter LOS and lower hospital treatment costs versus heparin bridging to warfarin.
Keywords: anticoagulation; bridging therapy; pulmonary embolism; rivaroxaban; warfarin.
© 2016 Pharmacotherapy Publications, Inc.