Primary anticoagulation with bivalirudin for patients with implantable ventricular assist devices.

Bivalirudin is a direct thrombin inhibitor that is increasingly used in patients undergoing mechanical circulatory support as it presents many advantages compared with unfractionated heparin. The aim of this study was to describe our experience with bivalirudin as primary anticoagulant in patients undergoing ventricular assist device (VAD) implantation. An observational study was performed on 12 consecutive patients undergoing VAD implantation at our institution. Patients received a continuous infusion of bivalirudin, with a starting dose of 0.025 mg/kg/h; the target activated partial thromboplastin time (aPTT) was between 45 and 60 s. Patients never received heparin during hospitalization nor had a prior diagnosis of heparin-induced thrombocytopenia (HIT). All patients received a continuous flow pump except one. Preoperative platelets count was 134 000 ± 64 000 platelets/mm(3) . Mean bivalirudin dose was 0.040 ± 0.026 mg/kg/h over the course of therapy (5-12 days). Lowest platelets count during treatment was 73 000 ± 23 000 platelets/mm(3) . No thromboembolic complications occurred. Two episodes of minor bleeding from chest tubes that subsided after reduction or temporary suspension of bivalirudin infusion were observed. Intensive care unit stay was 8 (7-17) days, and hospital stay was 25 (21-33) days. Bivalirudin is a valuable option for anticoagulation in patients with a VAD and can be easily monitored with aPTT. The use of a bivalirudin-based anticoagulation strategy in the early postoperative period may overcome many limitations of heparin and, above all, the risk of HIT, which is higher in patients undergoing VAD implantation. Bivalirudin should no longer be regarded as a second-line therapy for anticoagulation in patients with VAD. [Correction added on 6 December 2013, after first online publication: The dose of bivalirudin in the Abstract to 0.025 mg/kg/h].

Bivalirudin versus heparin as an anticoagulant during extracorporeal membrane oxygenation: a case-control study.

OBJECTIVE: Heparin-based anticoagulation for patients undergoing extracorporeal membrane oxygenation has many limitations, including a high risk of heparin-induced thrombocytopenia. However, little experience with other anticoagulants in these patients has been described. The aim of this study was to compare bivalirudin-based anticoagulation with heparin-based protocols in a population of patients treated with venovenous or venoarterial extracorporeal membrane oxygenation. DESIGN: In this case-control study, 10 patients received bivalirudin (cases) and 10 heparin (controls). The target activated partial thromboplastin time (aPTT) was 45 to 60 seconds. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: aPTT variations >20% of the previous value were much more frequent in patients treated with heparin than in patients receiving bivalirudin (52 v 24, p < 0.001). The number of corrections of the anticoagulant dose was higher in the heparin group compared with the bivalirudin group (58 v 51), although it did not reach statistical significance. Bleeding, thromboembolic complications, extracorporeal membrane oxygenation (ECMO) support duration, mortality, and the number of episodes of aPTT >80 seconds were not different between the 2 groups. A further analysis was performed in the bivalirudin group according to the presence of acute renal failure requiring continuous venovenous hemofiltration. The median bivalirudin dose in patients with or without hemofiltration was 0.041 (0.028-0.05) mg/kg/h and 0.028 (0-0.041) mg/kg/h, respectively (p = 0.2). CONCLUSIONS: Bivalirudin-based anticoagulation may represent a new method of anticoagulation for reducing thromboembolic and bleeding complications, which still jeopardize the application of extracorporeal membrane oxygenation. Moreover, bivalirudin is free from the risk of heparin-induced thrombocytopenia. Higher doses of bivalirudin may be needed in patients undergoing hemofiltration.