bivalirudin and Cardiomyopathy--Dilated

The direct thrombin inhibitor bivalirudin is an option for anticoagulation in patients with heparin induced thrombocytopenia (HIT) requiring cardiopulmonary bypass (CPB). There are a limited number of reports of pediatric patients in which bivalirudin has been used for anticoagulation for CPB. We present the case of an 11 year old male with acute onset heart failure secondary to idiopathic dilated cardiomyopathy that developed heparin induced thrombocytopenia with thrombosis (HITT). The patient was anticoagulated in the operating room with bivalirudin and placed on CPB for insertion of a HeartWare(®) Ventricular Assist Device (Heartware(®)). Modified techniques were utilized. This included use of the Terumo CDI 500 (Terumo Cardiovascular Systems, Inc.) in-line blood gas monitor which contains a heparin coated arterial shunt sensor. We flushed this sensor with buffered saline preoperatively and noted no significant decrease in platelet count postoperatively. The patient was successfully placed on the ventricular assist device and was subsequently listed for heart transplantation.

Topics: Anticoagulants; Cardiomyopathy, Dilated; Cardiopulmonary Bypass; Child; Heart Failure; Heart Transplantation; Heart-Assist Devices; Heparin; Hirudins; Humans; Male; Peptide Fragments; Recombinant Proteins; Thrombocytopenia; Thrombosis

Direct thrombin inhibitors are heparin alternatives for anticoagulation during cardiopulmonary bypass in patients with heparin-induced thrombocytopenia. We report a case of a large thrombus forming in the venous reservoir while using bivalirudin. We suggest that blood stasis associated with the full venous reservoir maintained in this case led to formation of a large thrombus at the top of the venous canister. Furthermore, activated clotting times may not accurately reflect the magnitude of anticoagulation when using direct thrombin inhibitors.

Topics: Anticoagulants; Antithrombins; Cardiomyopathy, Dilated; Fibrinolysis; Heart Transplantation; Heparin; Hirudins; Humans; Intra-Aortic Balloon Pumping; Male; Middle Aged; Peptide Fragments; Recombinant Proteins; Thrombocytopenia; Thrombosis; Treatment Failure; Whole Blood Coagulation Time

The temporary total artificial heart (TAH-t) has emerged as an effective bridge to transplantation for individuals with biventricular failure. Implantation of a TAH-t creates a hypercoagulable state requiring a multidrug approach that includes low-dose unfractionated heparin (UFH) in order to minimize thromboembolism. A concern with UFH is the development of heparin-dependent antibodies, which develop in up to 50% of patients receiving the drug as part of cardiopulmonary bypass. If UFH therapy continues postoperatively, the risk of heparin-induced thrombocytopenia approaches 3%. Small investigations have demonstrated that bivalirudin, given as a bolus of 0.75-1 mg/kg followed by an infusion at 1.75-2.5 mg/kg/hour, is an effective alternative to UFH for therapeutic anticoagulation during coronary artery bypass surgery, valve replacement, or both. We describe a series of five adults (age range 24-58 yrs) who received bivalirudin as an alternative to low-dose UFH after TAH-t implantation. None of the patients had documented heparin-induced thrombocytopenia. Treatment was started at the discretion of the treating physician, and adjustments were based principally on the results of thromboelastography. Additional general monitoring included activated partial thromboplastin time, prothrombin time, international normalized ratio, fibrinogen, D-dimer, platelet count, hemoglobin, hematocrit, and platelet aggregation studies. Bivalirudin therapy was continued until successful warfarin implementation. All five patients received bivalirudin in addition to standard antithrombotic therapy. Bivalirudin treatment started at a dosage of 0.005 or 0.01 mg/kg/hour with titration to maintain normocoagulability, which occurred (without concomitant warfarin therapy) within the dosage range of 0.01-0.02 mg/kg/hour. Duration of TAH-t implantation was a mean of 38.8 days (range 25-60 days), and bivalirudin was continued for a mean of 15.2 days (range 7-24 days). No major hemorrhagic events occurred during treatment, and all patients successfully transitioned to warfarin therapy. Low-dose bivalirudin, as an alternative to UFH, maintained normocoagulability after TAH-t implantation. Further investigation is warranted to define the role and dosing of bivalirudin in this situation.

Topics: Anticoagulants; Antithrombins; Cardiomyopathy, Dilated; Heart Transplantation; Heart, Artificial; Hirudins; Humans; Intraoperative Complications; Male; Middle Aged; Myocardial Ischemia; Partial Thromboplastin Time; Peptide Fragments; Prosthesis Implantation; Recombinant Proteins; Young Adult

Heparin-induced thrombocytopenia (HIT) is an increasingly common clinical finding in patients presenting for cardiac transplantation. Bivalrudin, a reversible direct thrombin inhibitor, is a molecular anti-coagulant with short half-life and the potential for removal by intraoperative hemofiltration. Herein we describe the dosing and intraoperative management of bivalrudin anti-coagulation in a patient undergoing urgent cardiac transplantation in the context of recently diagnosed HIT.

Topics: Adult; Anticoagulants; Cardiomyopathy, Dilated; Combined Modality Therapy; Dose-Response Relationship, Drug; Heart Failure; Heart Transplantation; Hemofiltration; Heparin; Hirudins; Humans; Intraoperative Care; Male; Peptide Fragments; Recombinant Proteins; Thrombin; Thrombocytopenia