Summary

SummaryConventional anticoagulation for symptomatic pulmonaryembolism consists of continuous intravenous unfractionatedheparin as a "bridge" to oral anticoagulation. This strategyrequires 5 days or more of intravenous heparin while oral vitaminK antagonists gradually achieve a therapeutic effect. Oralvitamin K antagonists require frequent blood testing to optimizedosing, and their interactions with other medications andfoods make regulation difficult.Therefore we tested a differentapproach to therapy: long-term enoxaparin monotherapy.We randomized 60 symptomatic pulmonary embolism patientsin a 2:1 ratio to 90 days of enoxaparin as monotherapy withoutwarfarin (N=40) or to intravenous unfractionated heparin as a"bridge" to warfarin, target INR 2.0-3.0 (N=20). Enoxaparinpatients received 1 mg/kg twice daily for 14 days during the acute phase followed by randomized assignment during thechronic phase to 1.0 mg/kg vs. 1.5 mg/kg once daily.In an intention-to-treat analysis, 3 of the 40 enoxaparin patientsdeveloped recurrent venous thromboembolism compared with0 of 20 standard therapy patients (p = 0.54). One of the 40enoxaparin patients had a major hemorrhagic complicationcompared with 2 of the 20 standard therapy patients (p = 0.26).Median hospital length of stay was shorter with enoxaparincompared to standard therapy (4 vs. 6 days) (p = 0.001).Following our study we can conclude that extended 3-monthtreatment with enoxaparin as monotherapy for symptomatic,acute pulmonary embolism is feasible and warrants furtherstudy in a large clinical trial.