ABRIDGE: Low Molecular Weight Heparin in Bridging Patients After Mechanical Valve Replacement

Patients who undergo mechanical heart valve replacement are usually placed on long-term oral anticoagulation (blood thinning) medication to prevent blood clots from forming on the mechanical valve. This is started in the hospital with intravenous unfractionated heparin; patients must remain in the hospital while on unfractionated heparin. At the same time, an oral blood thinner is started (warfarin). This process is commonly referred to as "bridging." Once the warfarin reaches the proper level, the intravenous heparin is stopped. This is a single center, non-randomized pilot study using twice a day enoxaparin injections in place of unfractionated heparin as a bridge to warfarin therapy. A total of approximately 100 patients will be enrolled. Patients will be instructed how to give the enoxaparin injections at home. Blood will be drawn every 1-2 days to monitor warfarin levels. Once discharged, patients will continue to have their blood level checked until warfarin is at the correct level, at which point enoxaparin will be discontinued. All patients who develop signs or symptoms of a stroke or abnormal blood clotting will be asked to return for an echocardiogram. An echocardiogram and 12-lead ECG will be done at approximately 30 days after the start of the study. Additionally the first 100 consecutive patients who fit the inclusion criteria but do not consent to the enoxaparin strategy will be asked to enter a registry that will monitor their hospital stay and information from their routine 30 day follow-up visit will be collected.