Anesthetic and Perioperative Considerations in Patients Undergoing Placement of Totally Implantable Replacement Hearts

Abstract

The recent successful implantation of the AbioCor im plantable replacement heart at the Rudd Heart-Lung Institute, Jewish Hospital, Louisville, KY, has renewed clinical interest in the use of the mechanical replace ment heart as therapy for intractable heart failure. Al though the number of orthotopic heart transplants has plateaued in the past decade, the number of patients requiring transplantation continues to increase. This supply/demand discrepancy continues to be the main catalyst for the research and development of other therapies for the failing heart. This review addresses perioperative considerations, monitoring modalities, and perioperative therapeutic interventions that may help guide the cardiac anesthesiologist through the challenges presented by implantation of total replace ment hearts in end-stage cardiac patients.

Total artificial heart system

“…A preinduction arterial catheter is mandatory for continuous blood pressure monitoring 10. Induction of general anesthesia is done with caution, accounting for severe biventricular failure, labile hemodynamics, and multisystem organ dysfunction 11. Central venous access is essential for central venous pressure (CVP) monitoring and administering fluids and medications.…”

“…Patients with TAH, like all other MCS devices, are at risk for thrombosis and embolic events due to activation of the coagulation system and hemolysis with the device. Upon cessation of bleeding, anticoagulation therapy with a heparin infusion (goal activated partial thromboplastin time of 40 to 60 s) and antiplatelet therapy (aspirin 81 to 324 mg) must be initiated, with eventual bridging to warfarin (target international normalized ratio of 2.5 to 3.0) 11. Postoperative anemia is common in TAH patients and is most commonly due to bleeding and hemolysis caused by mechanical valve sheering 7,10.…”

“…10 Inotropic and chronotropic support is redundant as the ventricular myocardium is removed, and the TAH settings will manage beat rate and cardiac output. 11 Clinically, SynCardia recommends the following driver settings for optimal TAH hemodynamic performance: a beat rate of 125 15 beats per minute, right ventricular drive pressure of 80 to 100 mm Hg, left ventricular drive pressure of 180 to 210 mm Hg (recommended to be ~50 mm Hg higher than a patient's target systolic blood pressure), right ventricular vacuum pressure of 0 to − 13 mm Hg, left ventricular vacuum pressure of 0 to − 13 mm Hg, and a percentage of cardiac cycle time spent in systole of 50 5% (Table 2). To avoid air entrainment across the inflow cuff suture lines, SynCardia recommends initiating vacuum-augmented filling after chest closure.…”

“…Upon cessation of bleeding, anticoagulation therapy with a heparin infusion (goal activated partial thromboplastin time of 40 to 60 s) and antiplatelet therapy (aspirin 81 to 324 mg) must be initiated, with eventual bridging to warfarin (target international normalized ratio of 2.5 to 3.0). 11 Postoperative anemia is common in TAH patients and is most commonly due to bleeding and hemolysis caused by mechanical valve sheering. 7,10 However, because patients receive TAH support as BTT, transfusion of blood products should be limited to avoid foreign antigen exposure.…”

“…10 Nesiritide, a recombinant form of the hormone, may be given as an infusion to protect renal function. 11…”