Feasibility of Outpatient Hemodialysis for Patients With Total Artificial Heart: A Case Series

Cardiorenal syndrome is a common comorbidity associated with heart failure, and prolonged hypoperfusion to the kidneys can result in chronic kidney disease (CKD).1 A review of articles published between 2000 and 2011 describing characteristics of heart failure estimated that 35–70% of heart failure patients also suffer from CKD.2 Further progression to end-stage renal disease (ESRD) and end-stage heart failure will necessitate the need for chronic dialysis while awaiting heart-kidney transplantation.

Heart transplant is the gold standard therapy for end-stage heart failure. Some patients may not qualify for heart transplants despite the medical necessity for a variety of reasons, including but not limited to: active malignancy, irreversible liver disease, and advanced pulmonary hypertension.3 Certain relative contraindications can be corrected with therapies or lifestyle modifications (i.e. obesity, uncontrolled diabetes, transient renal dysfunction). In cases where irreversible contraindications exist, durable mechanical circulatory support (MCS) is recommended as “destination therapy” (DT). In cases where relative contraindications exist due to reversible or transient abnormalities, MCS therapy is considered a “bridge to transplant” (BTT) or “bridge to eligibility” (BTE).

Total artificial hearts (TAH) are used in patients suffering from end-stage heart failure who don’t qualify for a heart transplant or left ventricular assist device (LVAD). The first total artificial heart, the JarvikTM 7, was implanted in a human in 1982. Today, the device is known as the SynCardiaTMTotal Artificial Heart (S-TAH), and is currently the only FDA-approved TAH in the United States.4

Acute kidney injury (AKI) is a common postoperative complication associated with TAH implant.5 Postoperative AKI is likely multifactorial, with proposed mechanisms including sudden withdrawal of B-type natriuretic peptide following removal of the native ventricles, device-related hemolysis, and pre-implant status (i.e., cardiogenic shock).6 While some patients recover renal function, others progress to CKD and ESRD, resulting in the need for chronic dialysis.

Most dialysis centers aren’t trained with TAHs and do not have protocols or resources in place to manage these patients on an outpatient basis. Hence, patients who are actively being dialyzed are either not candidates for TAH, or, if a TAH is implanted, the patient has to remain in the hospital on dialysis until they are subsequently transplanted. This results in an increased emotional burden on the patient and increased cost of care. To our knowledge, there is only one case describing a TAH patient maintained on outpatient dialysis, and he did not survive to transplant.7

To overcome the lack of resources for TAH patients with renal failure, our center actively prepared several dialysis centers in the community to manage this high-risk population (see Supplemental Digital Content 1, https://links.lww.com/ASAIO/A904 and Supplemental Digital Content 2, https://links.lww.com/ASAIO/A903). Here we present four cases from a single center who were maintained on outpatient dialysis after implantation of TAH; two survived heart-kidney transplant while on dialysis, one did not survive to transplant, and one was successfully weaned off dialysis as an outpatient and subsequently received a heart transplant. This report illustrates the successful management of four patients' status post-TAH on outpatient dialysis, indicating that this is a viable option for patients with TAH requiring hemodialysis.

Materials and Methods

A retrospective chart analysis was conducted on all patients implanted with a TAH at Banner University Medical Center Phoenix (BUMCP) from 2019 to 2021. Patients were included in the case series if they required outpatient hemodialysis following the implant. Patients were excluded from the case series if they did not require outpatient hemodialysis post-implant, or if the patient was deceased before discharge from index hospitalization. A total of 11 patients were implanted with TAHs at BUMCP during the study period, and 4 met the inclusion criteria for the study.

The intervention performed in this study required preparing local outpatient dialysis centers to service the four patients that met the inclusion criteria. Initially, an HD center was identified near a patient’s residence. A total of two HD centers were selected to provide service in this study. A policy was drafted and approved between each HD center and the implanting program. Policies included the provision of initial and ongoing education from the implanting center, blood pressure management, emergency guidelines, and caregiver/MCS coordinator expectations. HD staff was not responsible for the patient’s equipment or its management, including dressing changes. Labs were drawn weekly at the HD center (CMP, CBC, PT/INR, Prealbumin, and CRP) and reviewed by the implanting center.

Two separate 1-hour training sessions were scheduled with each HD center’s RN and technician staff. Staff received a comprehensive educational presentation (Supplemental Digital Content 1, https://links.lww.com/ASAIO/A904) including general mechanics of the device and accessories, power sources, interpreting device alarms, interpreting device readings, and medical risks associated with the device. Physical training included a physical demonstration of the S-TAH ventricles while attached to an operating Freedom Driver, device alarm management, emergency management, hemodynamic monitoring, and Freedom Driver exchange practices. Upon completion of training, the training staff signed off on a checklist to document that all skills were assessed to be satisfactory (Supplemental Digital Content 2, https://links.lww.com/ASAIO/A903). A trained caregiver was present during each HD run, and centers had access to a 24-hour on-call MCS coordinator line for questions and assistance.

Case Report Case presentation #1

A patient is a 54-year-old man with a cardiac history of dilated, presumed familial, nonischemic cardiomyopathy with moderate RV dysfunction (Table 1). Another pertinent medical history significant for DMII, COPD, amiodarone-induced hyperthyroidism, and CKD Stage III. The patient was maintained on IV milrinone therapy as an outpatient while undergoing transplant workup and was denied for transplant due to thyrotoxicosis requiring high-dose prednisone therapy.

Table 1. - Case Details of TAH Patients Managed on OP HD Case 1 Case 2 Case 3 Case 4 Date of Implant 10/9/2019 7/21/2019 9/16/2019 8/19/2020 Etiology of Heart Failure Dilated familial NICM Dilated valvular NICM Dilated radiation-induced NICM Drug-induced NICM CKD Prior to Implant Stage III Stage III No No Age at Implant (yrs) 54 56 61 31 Device Implanted SyncardiaTM 70cc TAH as DT SyncardiaTM 70cc TAH as BTT SyncardiaTM 70cc TAH as DT SyncardiaTM 70cc TAH as BTT INTERMACS profile 2-TCS (IABP)/ milrinone 2-TCS (IABP)/ milrinone 3-milrinone 3-milrinone Creatinine at Time of Implant 3.08 3.64 1.3 1.41 POD Dialysis Initiated 6 0 9 4 POD Discharge 76 90 117 33 Frequency of OP HD 3×/week 3×/week 3×/week 3×/week Days Managed on OP HD 777 466 86 42 Patient Outcome to Transplant Transplanted-heart/kidney Transplanted-heart/kidney Deceased Transplanted-heart

HD, hemodialysis; NICM, nonischemic cardiomyopathy; OP, outpatient; POD, post-op day.

Given the rapid deterioration of his clinical status, the patient was implanted with a TAH. The immediate postoperative course was complicated by AKI on CKD. He was discharged to acute rehab on POD57 and then discharged home with outpatient HD on POD76.

The patient remained on scheduled OP HD for 777 days, during which time he was readmitted twice for subtherapeutic INR and once for supratherapeutic INR/pulmonary congestion (Table 2). He received a heart-kidney transplant 863 days after implantation of the TAH.

Table 2. - Adverse Events Requiring Rehospitalization in TAH Patients on OP HD Rehospitalization Case 1 Case 2 Case 3 Case 4 1 Subtherapeutic INR Supratherapeutic INR, anemia Hypertension, sepsis, spontaneous subdural hematoma Anemia 2 Subtherapeutic INR Subtherapeutic INR Epileptic seizure Subtherapeutic INR, sepsis 3 Supratherapeutic INR, Pulmonary congestion Subtherapeutic INR, anemia - Supratherapeutic INR 4 - Supratherapeutic INR, anemia, hypervolemia - Supratherapeutic INR, anemia, driveline infection 5 - Hypertension - - 6 - Hypertension, anemia - - 7 - Subtherapeutic INR, anemia - - 8 - Hypovolemia - - 9 - Anemia - -
Case presentation #2

The patient is a 56-year-old woman with a past medical history significant for dilated, presumed valvular nonischemic cardiomyopathy, mild-mod RV dysfunction, s/p bioprosthetic mitral valve with subsequent replacement, ventricular fibrillation, and CKD stage III (Table 1). The patient was admitted to the hospital in biventricular decompensated heart failure for advanced therapy evaluation. Due to poor hemodynamics following right heart catheterization, an IABP was placed and the patient was started on IV inotropic therapy. A formal transplant evaluation was unable to be completed due to the rapid deterioration of the patient’s clinical status, and she was therefore implanted with a TAH. The postoperative course was complicated by AKI requiring initiation of CRRT on POD0. She was transitioned to HD on POD43, discharged to acute inpatient rehab on POD72, and then home on POD90.

The patient remained on scheduled OP HD for 466 days, during which time she had several readmissions for subtherapeutic INR, anemia, and hypertension (Table 2). She received a heart transplant 556 days after implantation of the TAH.

Case presentation #3

The patient is a 61-year-old woman with a past cardiac history significant for dilated, nonischemic (presumed familial/radiation-induced) cardiomyopathy (Table 1). Additional medical history significant for DMII, DVT, pulmonary cocci with lung cavitation, breast cancer s/p lumpectomy and chemo/XRT, and pulmonary embolism. The patient was maintained on IV milrinone therapy as an outpatient before being admitted to the hospital with decompensated heart failure. The patient did not have a prior history of renal dysfunction, but creatinine/eGFR worsened during this admission, likely due to cardiorenal syndrome. Advanced therapy evaluation was completed, and she was declined for transplant due to a history of cancer <5 years prior. She underwent implantation of TAH and required initiation of CRRT on POD7 due to worsening renal function. She was transitioned to SLED on POD56, and further to HD on POD66. She was discharged to acute rehab on POD91, and then home on POD117.

The patient remained on scheduled OP HD for 86 days until she was re-hospitalized for a subdural hematoma after being found unresponsive at home (Table 2). She was intubated and found to be in myoclonic status epilepticus on EEG with anoxic brain injury on a CT scan. Her condition failed to improve and she was placed on comfort care 203 days after implantation of the TAH.

Case presentation #4

The patient is a 31-year-old man with a past medical history significant for syringomyelia of the spinal cord and active polysubstance abuse (THC and MDMA), who was diagnosed with nonischemic (presumed drug-induced and familial) cardiomyopathy after being hospitalized with cardiogenic shock (Table 1). He was maintained on IV milrinone as an outpatient while undergoing drug rehab but was readmitted monthly for decompensated heart failure. Given the patient’s failure to thrive on maximal outpatient therapy, the decision was made to escalate to advanced therapies. He was unable to be listed for transplant due to incomplete rehabilitation. He was implanted with a TAH.

The postoperative course was complicated by renal failure requiring initiation of daily hemodialysis on POD4. The patient was discharged home on POD33.

Renal function normalized shortly after, permitting cessation of dialysis after 33 days of outpatient therapy. He was subsequently readmitted several times for anticoagulation adjustments, anemia, and a driveline infection (Table 2). After social barriers to transplant were appeased, the patient underwent a heart transplant 363 days after implantation of the TAH.

Discussion

TAHs are implanted in patients with advanced heart failure who are deemed advanced therapy candidates but do not meet the criteria for an immediate heart transplant or LVAD. While TAHs can sometimes improve existing renal dysfunction through increased perfusion to the kidneys, worsening renal function and new-onset AKI are known postoperative complications associated with device implants.5,6 Predicting which category patients will fall into is a difficult task for providers. As more centers begin utilizing the TAH in their advanced heart failure programs, the issue of maintaining TAH patients on dialysis in the community will become more prominent. Typically, patients who are status post-TAH implant remain hospitalized while on dialysis until renal function recovers or they become transplant eligible. This case series provides evidence to the feasibility of managing TAH patients on dialysis as outpatients.

Several factors are of primary importance in the management of TAH patients on dialysis. In the cases described above, supra- or subtherapeutic INR was the most common chief complaint during rehospitalization (64% of readmissions), followed by anemia. Hemolytic anemia and bleeding complications are two primary concerns both in patients with TAHs4 and in patients who are anticoagulated while on dialysis.8 The TAH and dialyzer cause turbulent blood flow and expose cells to artificial surfaces, which places mechanical stress on RBCs.9 Given these concerns, close monitoring of CBC and INR is imperative in this population to minimize anemia and bleeding/thrombotic events.

Dialysis centers require proper resources and training when managing high-risk patients such as those with TAHs. Dialysis centers typically don’t accept patients with TAHs due to the unfamiliarity of dialysis staff with this patient population. Our center developed training materials and protocols to provide dialysis centers with the necessary skills and information to care for these patients (Supplemental Digital Content 1, https://links.lww.com/ASAIO/A904 and Supplemental Digital Content 2, https://links.lww.com/ASAIO/A903).

Our aim is that these cases serve as an example of the viability of maintaining TAH patients on outpatient dialysis. Heart disease is the leading cause of death in the United States (CDC), and the need for heart transplantation will continue to rise. Because of this, the TAH will become an increasingly useful therapy for patients with biventricular heart failure, incessant ventricular arrhythmias, restrictive cardiomyopathy, and those in need of re-transplant. Some patients may require years to reach transplant eligibility and find a well-matched donor. Maintaining TAH patients with renal failure on outpatient dialysis provides an option for these patients. Allowing patients to return to the community as opposed to remaining inpatient until a transplant can increase patient quality of life and decrease inpatient hospital burden and costs. These cases confirm that this is a feasible option for patients who’ve developed dialysis-dependent ESRD after TAH implantation.

References 1. Ronco C, Haapio M, House AA, Anavekar N, Bellomo R: Cardiorenal syndrome. J Am Coll Cardiol 52: 1527–1539, 2008. 2. Shiba N, Shimokawa H: Chronic kidney disease and heart failure—Bidirectional close link and common therapeutic goal. J Cardiol 57: 8–17, 2011. 3. Alraies MC, Eckman P: Adult heart transplant: Indications and outcomes. J Thorac Dis 6: 1120–1128, 2014. 4. Cook JA, Shah KB, Quader MA, et al.: The total artificial heart. J Thorac Dis 7: 2172–2180, 2015. 5. Kalya A, Goel R, Boyle K, et al.: Impact of syncardia total artificial heart on renal function in patients bridged to heart transplant. Am J Transplant 11: 301, 2011. 6. Shah KB: Renal function after implantation of the total artificial heart. Ann Cardiothorac Surg 9: 124–125, 2020. 7. Hanna RM, Hasnain H, Kamgar M, Hanna M, Minasian R, Wilson J: Patient with a total artificial heart maintained on outpatient dialysis while listed for combined organ transplant, a single center experience. Hemodial Int 21: E69–E72, 2017. 8. Nochaiwong S, Ruengorn C, Awiphan R, Dandecha P, Noppakun K, Phrommintikul A: Efficacy and safety of warfarin in dialysis patients with atrial fibrillation: A systematic review and meta-analysis. Open Heart 3: e000441, 2016. 9. Fischer K-G: Essentials of anticoagulation in hemodialysis. Hemodial Int 11: 178–189, 2007.

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