Safety of parenteral anticoagulation as a bridge to warfarin in patients undergoing mechanical aortic valve replacement

Objective: To evaluate bleeding rates among patients who received a mechanical aortic valve replacement (mAVR) treated with warfarin monotherapy versus warfarin with a therapeutic parenteral anticoagulant bridge. Methods: This retrospective, single-center, observational study included patients at least 18 years old who received an mAVR and had anticoagulation ordered by the end of postoperative day 2. Exclusion criteria included an INR goal other than 2-3, a hypercoagulable state, postoperative mechanical circulatory support, delayed sternal closure, pregnancy or incarceration. The primary outcome was International Society of Thrombosis and Hemostasis major bleeding until hospital discharge or 30 days after valve replacement, whichever came first. Secondary outcomes included thromboembolic events, hospital length of stay, and mortality. Conclusions: The use of therapeutic parenteral anticoagulation with warfarin after mAVR significantly increased the rate of major bleeding compared to warfarin monotherapy. Larger prospective studies are needed to confirm these findings.