INTRODUCTION
The Syncardia total artificial heart (TAH) is a mechanical circulatory assist device that serves as bridge to orthotopic heart transplantation in patients with irreversible biventricular failure. Challenges of destination therapy with TAH include thromboembolic disease, bleeding, infections from percutaneous drivelines and long-term maintenance of pulmonary-systemic circulatory balance. We describe the first case of long-term use of Syncardia TAH for failed OHT complicated by acute pulmonary embolism that exacerbated underlying pulmonary hypertension and precipitated irreversible right sided TAH failure.
CASE DESCRIPTION
A 30-year-old Caucasian man with a background of idiopathic dilated cardiomyopathy with TAH following failed OHT secondary to antibody mediated rejection, pulmonary hypertension, anemia, DM, and ESRD on hemodialysis presented to the hospital for complaint intermittent loss of consciousness with persistent alarming from device indicating incomplete Right-sided ejection not resolved by exchanging to alternate external driver. In the ED, an immediate concern for device malfunction was raised prompting chest CT-angiogram demonstrating acute large filling defect in the left interlobar pulmonary artery extending into the lower lobe segmental branches. INR upon presentation was therapeutic 3.7 on outpatient anticoagulation regimen including coumadin, ASA and dipyridamole.
The patient was admitted for device malfunction secondary to embolic burden resulting in Right-sided device failure. Initial therapies included heparin drip, inhaled nitric oxide, epoprostenol, and CRRT, in attempt to overcome high PA pressures. An IVC cavogram was performed with right heart angiography and pulmonary angiography. The IVC was patent, free of thrombus and the TAH valve leaflets were visualized in real-time fluoroscopy with normal motion. No discrete right heart or pulmonary outflow tract thrombus was appreciated.
The patient’s clinical progression despite above supportive therapy was significant for multiple syncopal events secondary to right-sided device failures, requiring intermittent manual pumping of TAH. Inspection of device data and flow graphics did not reveal mechanical failure as internal components as well as external drive lines were appropriately functioning. The increasing frequency of syncopal events prompted systemic fibrinolysis however device failure rate did not improve and the patient developed worsening multiorgan failure that prompted transition of care to comfort measures. Patient has died 12 days following admission after subsequent device failure.
DISCUSSION The longest documented time a patient receiving TAH support is 1374 days prior to successful heart transplant. The patient described in the case report was supported by TAH device for a total of 1067 days. Complications associated with long term TAH implantation include infection, bleeding, renal failure, chronic anemia and thromboembolic disease. The unique nature of this case is the development of acute pulmonary emboli which had not been previously reported as the majority of reported thromboembolic phenomena were largely associated with neurologic sequelae. Platelet activation and thrombogenecity were likely enhanced with the diaphragm rupture despite full anticoagulation prompting the discussion of thrombolytic therapy and its appropriate use in this extenuating circumstance in the management of grossly elevated PVR. As TAH has been approved for prolonged use as transplant alternative, additional attention should be directed toward the optimization of the device for thromboresistance and durability
