Thrombosis during off pump LVAD placement in a patient with heparin induced thrombocytopenia using bivalirudin

Abstract

Here we present our attempt at off pump HeartMate II left ventricular assist device (LVAD) implantation using the anticoagulant bivalirudin in a patient with heparin induced thrombocytopenia, which resulted in thrombosis within the LVAD device. This required that our procedure be converted to on pump, and a new HeartMate II LVAD device to be implanted. In our view, this thrombotic event may have been caused by a number of factors that include bivalirudin’s (1) short half-life of about 20 minutes, (2) decreased activity with blood stasis, (3) inability to prevent clot propagation, and (4) uncertainty with real-time monitoring of therapeutic levels. To prevent future thrombotic events, it may be beneficial to immediately deair the LVAD device prior to the coring of the left ventricle during off pump LVAD placement. In addition, a solution other than blood may be used for priming. If blood is used for priming of the LVAD device, the duration of blood stasis should not exceed 20 minutes when bivalirudin is being used for anticoagulation. Furthermore, this case emphasizes the importance of having a backup LVAD device available and ready to use during surgical procedures.

The use of cangrelor with heparin for left ventricular assist device implantation in a patient with acute heparin-induced thrombocytopenia

“…Modifications to bypass circuit to avoid blood stagnation and thrombus formation within the circuit are crucial. During implantation, stasis of blood inside the LVAD pump can lead to thrombus formation on the rotor or housing which might negatively affect device operation [ 7 ]. Lastly, clearance of bivalirudin is dependent on renal function.…”

“…Patients with impaired renal function are at risk of bleeding complications due to significant reduction in plasma clearance of up to 24% [ 8 ]. There are case reports describing prolonged coagulopathy post LVAD implantation in HIT patients using bivalirudin [ 7 , 9 , 10 ].…”

Abciximab/Heparin Therapy for Left Ventricular Assist Device Implantation in Patients With Heparin-Induced Thrombocytopenia

“…Bivalirudin, a direct thrombin inhibitor with a rapid onset, short half-life and rapid plasma clearance by a combination of renal and proteolytic mechanisms [24], has become a popular anticoagulant for HIT patients undergoing CPB [25]. In HIT patients who need urgent LVAD implantation, the reported protocol using bivalirudin is summarized in Table 4 [24,26,27]. The bivalirudin protocol raises concerns regarding bleeding without an appropriate antidote to reverse its anticoagulation effect.…”

“…The bivalirudin protocol raises concerns regarding bleeding without an appropriate antidote to reverse its anticoagulation effect. Awad and colleagues [27] reported significant clot formation during off-pump LVAD implantation. Some authors have cautioned against its use in stagnant blood within the CPB circuit during cardiac operations [25,28].…”

Cardiopulmonary Bypass Without Heparin

“…A recent report also noted the development of thrombosis within an axial-flow left ventricular assist device during a period of stasis in a patient treated with bivalirudin. 41…”