Successful Use of Fondaparinux for Bridging Early After Aortic and Mitral Mechanical Heart Valve Replacement

Abstract

To report a case of successful use of fondaparinux for bridging early after aortic and mitral mechanical heart valve replacement (MHVR). A 71-year-old female underwent aortic and mitral valve replacements with St. Jude medical bileaflet prostheses, as well as DeVega tricuspid annuloplasty and coronary artery bypass graft. Anticoagulation was initially withheld following the procedure because of thrombocytopenia, large amount of chest tube drainage (~1 L/day), and concerns regarding postoperative bleeding. The thrombocytopenia (baseline platelet count 183 x 10(3)/μL; postoperative platelet count 44 × 10(3)/μL) was thought to be a consequence of the cardiopulmonary bypass; there was a low probability of heparin-induced thrombocytopenia. However, the care team preferred to avoid heparin products and initiated fondaparinux 7.5 mg subcutaneously once daily on postoperative day 8 once the patient's platelet count had recovered to >100 x 10(3)/μL. The treatment was bridged to warfarin on postoperative day 13 and the patient was discharged home after receiving 8 days of fondaparinux. Throughout the patient's hospitalization and upon follow-up on postoperative day 31, there were no signs or symptoms of thromboembolic events or bleeding. Unfractionated heparin and low-molecular-weight heparins are the standard of care for bridging to warfarin in patients with MHVR. The use of fondaparinux following MHVR has not been studied in randomized controlled trials. In vitro studies support the effectiveness of fondaparinux in preventing thrombus formation on mechanical heart valves. However, the only data available in humans as of December 2011 are 3 case reports. Two of these case reports described the successful use of fondaparinux for anticoagulation in a patient with an aortic valve replacement. In the third case report, the patient had an aortic and mitral valve replacement. Our case report is novel because it describes the use of fondaparinux early after MHVR, which is the most critical time period for effective thromboprophylaxis. The use of fondaparinux for postoperative bridging in our patient early after combined aortic and mitral MHVR was effective. However, until studies evaluate the efficacy and safety of fondaparinux in patients with MHVR, its use should be considered only when heparin products are contraindicated.