Outpatient Dalteparin Peri-Procedure Bridge Therapy In Patients Maintained On Long Term Warfarin
Background: Peri-operative anticoagulation management for patients maintained on chronic warfarin therapy in need for surgery or invasive procedures is controversial. Such data is lacking in patients with documented hypercoagulable states and history of ischemic stroke. Methods: This prospective cohort study evaluated the feasibility, efficacy, safety, and cost-effectiveness of peri-operative dalteparin bridge therapy in patients maintained on long-term warfarin undergoing surgical or invasive diagnostic procedures. Twenty one consecutive patients with documented hypercoagulable states (protein C defficiency, protein S defficiency, antiphospholipid antibody syndrome) and a history of ischemic stroke were included in the study. Warfarin was stopped 4 days prior to surgery and was restarted the night of surgery , once hemostasis was achieved, at the pre-operative dose. Dalteparin 100 IU/Kg given subcutaneously every 12 hours was initiated 3 days prior surgery and continued until a therapeutic international normalized ratio was reached after surgery. On the day of surgery, the morning dalteparin dose was held. Data was recorded at the completion of dalteparin therapy and at 3 months of follow-up on recurrent thromboembolic events, and major and minor bleeding events. An economic analysis compared outpatient dalteparin bridge therapy with inpatient intravenous unfractionated heparin therapy. Results: The 21 patients underwent 29 surgical procedures: dental surgery (15), colonoscopy (5), eye surgery (3), vascular surgery (4), surgical biopsies (2). No patients suffered an embolic event during the 3 month follow-up period. There were no major bleeding events, and there were 8 (38%) patients with a minor bleeding event (bruising at injection site). All patients self administered the injections. An average of 6.5 hospital days were avoided per patient. This resulted in cost savings of $3250.00 per patient treated with dalteparin. Conclusion: Dalteparin appears to be a feasible, safe, and cost-effective alternative to inpatient intravenous heparin for peri-procedure bridge anticoagulation therapy in stroke patients.