Venous thromboembolism (VTE) and major bleeding are associated with substantial morbidity and mortality. We sought to compare in a real-world setting the effectiveness of fondaparinux and enoxaparin as treatment for persons hospitalized with VTE.
We reviewed billing records of patients hospitalized with deep vein thrombosis (DVT), pulmonary embolism (PE), or both (according to ICD-9 diagnosis codes) from >550 US acute care hospitals. Primary outcomes were hospital readmissions for recurrent VTEs or major bleeding within 30 days after discharge. Time from discharge to readmission for recurrent VTE or major bleeding was a secondary endpoint. We utilized logistic regression and Cox-proportional hazard modeling to control for potential confounders (eg, demographic, clinical, and hospital characteristics).
The cohort included 43,360 subjects (fondaparinux: n=809; enoxaparin: n=42,551). Fondaparinux-treated patients were younger, had a higher comorbidity burden, and more VTE risk factors. Crude readmission rates for VTE were 2.7% and 2.6% for fondaparinux and enoxaparin, respectively; the adjusted analysis confirmed the similarity in readmission rates (adjusted OR for readmission with fondaparinux: 0.810, p=0.94). Both crude and adjusted readmission rates for major bleeding events were similar between treatments (unadjusted rates: fondaparinux: 0.6% and enoxaparin: 0.7%, adjusted OR for fondaparinux: 0.799, p=0.62) There was no difference statistically in time to rehospitalization based on treatment option. Readmission rates for VTE and major bleeding did not differ between fondaparinux and enoxaparin-treated patients, irrespective of whether the VTE was present at time of index hospitalization or if it arose as a complication of hospitalization.
In a naturalistic setting, acute inpatient VTE treatment with fondaparinux, as compared with enoxaparin, is associated with similar risk for readmission due to VTE recurrence or major bleeding.
In a naturalistic setting, fondaparinux and enoxaparin appear to have comparable effectiveness, with similarly low bleeding risk, for acute anticoagulation for hospitalized patients with VTE. Clinicians therefore should consider other factors (eg, ease of dosing, frequency of administration, cost) when selecting between these agents for this population.
Andrew Shorr, Grant monies (from industry related sources) Astellas, GSK, J and J, Pfizer, Sanofi; Consultant fee, speaker bureau, advisory committee, etc. Astellas, BI, GSK, J and J, Medicines Co. Merck, Pfizer, Sanofi, Theravance; Other This project was supported by GSK; No Product/Research Disclosure Information