The failing Fontan: what's NEXT...?

The Fontan procedure represents the final stage of the transition to single ventricle physiology. Conversion of very complex congenital heart anatomy, such as hypoplastic left heart syndrome, double-outlet right ventricle or double-inlet left ventricle, to a single ventricle has grown in popularity as morbidity and mortality have improved. As these patients grow, survivors are at risk for impaired ventricular dysfunction, plastic bronchitis, protein-losing enteropathy and late failure. Late failing Fontan patients represent a particularly vexing scenario for clinicians, as the only durable treatment option is cardiac transplantation. However, in the short-term, some of these patients require support beyond medical management, with mechanical circulatory support via extracorporeal life support or a ventricular assist device. We report the successful bridge of an adolescent female post-Fontan conversion with late severe cardiac failure. The patient was initially resuscitated with extracorporeal life support, transitioned to a single Berlin Heart EXCOR® ventricular assist device and, subsequently, underwent successful cardiac transplantation.

Total artificial heart in the pediatric patient with biventricular heart failure.

Mechanical circulatory support emerged for the pediatric population in the late 1980s as a bridge to cardiac transplantation. The Total Artificial Heart (TAH-t) (SynCardia Systems Inc., Tuscon, AZ) has been approved for compassionate use by the Food and Drug Administration for patients with end-stage biventricular heart failure as a bridge to heart transplantation since 1985 and has had FDA approval since 2004. However, of the 1,061 patients placed on the TAH-t, only 21 (2%) were under the age 18. SynCardia Systems, Inc. recommends a minimum patient body surface area (BSA) of 1.7 m(2), thus, limiting pediatric application of this device. This unique case report shares this pediatric institution's first experience with the TAH-t. A 14-year-old male was admitted with dilated cardiomyopathy and severe biventricular heart failure. The patient rapidly decompensated, requiring extracorporeal life support. An echocardiogram revealed severe biventricular dysfunction and diffuse clot formation in the left ventricle and outflow tract. The decision was made to transition to biventricular assist device. The biventricular failure and clot formation helped guide the team to the TAH-t, in spite of a BSA (1.5 m(2)) below the recommendation of 1.7 m(2). A computed tomography (CT) scan of the thorax, in conjunction with a novel three-dimensional (3D) modeling system and team, assisted in determining appropriate fit. Chest CT and 3D modeling following implantation were utilized to determine all major vascular structures were unobstructed and the bronchi were open. The virtual 3D model confirmed appropriate device fit with no evidence of compression to the left pulmonary veins. The postoperative course was complicated by a left lung opacification. The left lung anomalies proved to be atelectasis and improved with aggressive recruitment maneuvers. The patient was supported for 11 days prior to transplantation. Chest CT and 3D modeling were crucial in assessing whether the device would fit, as well as postoperative complications in this smaller pediatric patient.

Concurrent pulmonary Aspergillus fumigatus and mucor infection in a cardiac transplant recipient: a case report.

Invasive fungal infections are a significant complication of solid organ transplantation. Here we report the first case of concurrent invasive pulmonary fungal infection caused by Aspergillus fumigatus and Mucor species in a heart transplant recipient. Polymicrobial mold infection is rare but should be considered in solid organ transplant recipients who fail to respond to initial antifungal therapy targeting a single organism. It is also of interest that in addition to potent immunosuppression and prolonged voriconazole therapy, possible airway fungal colonization following hurricane Katrina cleaning efforts might have contributed to this dual invasive mold infection.

Synthetic membrane neo-pericardium facilitates total artificial heart explantation.

BACKGROUND: In the past, explantation of the Cardio West total artificial heart (TAH) has been technically challenging because of the presence of dense adhesions and extremely thickened pericardium. To prevent this, we constructed a synthetic neo-pericardium in 14 patients. METHODS: Using expanded polytetrafluoroethylene (e-PTFE) membrane, we constructed a pericardium within the pericardium, or "neo-pericardium," completely covering the Cardio West TAH separating the native atria from the native pericardium, and wrapping the ascending aorta from the outflow conduit distally for about 5 to 7 cm. RESULTS: Of the 14 patients, 9 were transplanted and could be evaluated, 3 died on device support, and 2 are currently on device support. In each case, we attained faster (by 25 minutes) and easier reentry through the sternum. Surgical planes around the aorta, over the right and left atria, and throughout the pericardial space became apparent immediately after e-PTFE membrane removal. The pericardium and related tissues although slightly thickened (<2 mm) were pliable compared with our previous 36 patients, with very thick adherent pericardium over the device and native atria. CONCLUSIONS: The plastic materials forming the ventricular housing and drivelines of the Cardio West TAH and the Dacron outflow conduits have in the past caused profound local inflammatory reactions, resulting in extremely dense adhesions and thickened adherent pericardium. Using e-PTFE membrane to fashion a complete neo-pericardium and to wrap the ascending aorta at the time of Cardio West implantation dramatically reduces adhesions and pericardial thickening and facilitates explantation.

Bridge to transplantation with a Thoratec left ventricular assist device in a 17-kg child.

A Thoratec left ventricular assist device (LVAD) was used to support a 7-year-old 17-kg boy with viral cardiomyopathy for 23 days before heart transplantation. The boy is still living more than 1 year posttransplant, and functional except for some spastic paresis of the left hand, a residual from a stroke during device support. He is the smallest person to be supported with this device. We discuss techniques for using the Thoratec in children.

Comparison of the CardioWest total artificial heart, the novacor left ventricular assist system and the thoratec ventricular assist system in bridge to transplantation.

BACKGROUND: Device selection has historically been supported by minimal comparative data. Since 1994, we have implanted 43 patients with the CardioWest Total Artificial Heart (CW), 23 with the Novacor Left Ventricular Assist System (N), and 26 with the Thoratec Ventricular Assist System (T). This experience provides a basis for our device selection criteria. METHODS: We reviewed retrospectively the results for survival, stroke, and infection in the CW, N, and T groups. Statistical methods included the Student's t-test, chi2 analysis, and Kaplan-Meier actuarial survival curves. RESULTS: The T group patients were younger and smaller sized than the CW or N group. The CW group had the highest mean central venous pressure (CVP) and lowest mean cardiac index. Survival to transplantation was 75% for CW, 57% for N, and 38% for T. Multiple organ failure postimplant caused most deaths in the CW and T groups. Right heart failure and stroke caused most N deaths. Linearized stroke rates (event/patient-month) were 0.03 for CW, 0.28 for N, and 0.08 for T. Serious infections were found in 20% of CW, 30% of N, and 8% of T patients, but linearized rates showed little difference and death from infection was rare. CONCLUSIONS: The N device should be used in "stable" patients with body surface area (BSA) greater than 1.7 m2 and with minimal right heart failure. Unstable patients with biventricular failure should receive a CW if the BSA is greater than 1.7 m2 or a T if they are smaller.

Update on the total artificial heart.

There has been a quest for an artificial organ that can replace the heart for decades. Remarkable advances were made in the second half of the twentieth century in the fields of medicine and engineering that led to the development of several devices with the intention of totally replacing the human heart. Some of these devices, like the Jarvik artificial heart, were utilized initially as a permanent replacement for the failing heart. It became more successful as a bridge to heart transplantation (BTT) in the years that followed its introduction. Currently the CardioWest total artificial heart (TAH) is the only device in clinical use with the intention of bridging patients to heart transplantation. Two new TAHs are being developed with the intention of being used as an alternative to transplantation (ATT) or on a permanent basis. The next 100 years will bring revolutionary new designs and advances in the field of end stage heart disease that may only be ideas at the present time.

The CardioWest total artificial heart as a bridge to transplantation.

The CardioWest total artificial heart (TAH), formerly known as the Jarvik-7 and then the Symbion heart, is the only TAH in current clinical use. A new study, approved by the Food and Drug Administration (FDA), was initiated in 1993 with the goal of approving this pump for commercial release. Since then, 145 CardioWest TAHs have been implanted, including 37 pumps in 36 patients at our center. Our 36 patients were studied prospectively according to the investigational device exemption protocol approved by the FDA. Clinical and hemodynamic data obtained upon patients' entry into the study identified this group as mortally ill. After receiving a CardioWest TAH, 29 of the 36 patients (81%) survived to heart transplantation, and 26 (72% of the total group and 90% of the transplant recipients) have survived for up to 7 years (average, 24 months). Multicomponent anticoagulation, based on readily available tests, and the intrinsic properties of the TAH have resulted in a low linearized stroke rate of 0.48 event per patient-year. There have been no device-related mediastinal infections. In dying patients with nonexistent or severely compromised biventricular function, the CardioWest TAH has proved safe and effective, allowing a 72% survival rate for an average of 24 months.

Blood loss and transfusion requirements in patients implanted with a mechanical circulatory support device undergoing cardiac transplantation.

Patients implanted with mechanical circulatory support devices (MCSD's) are at high risk for post-operative bleeding at cardiac transplantation. However, the magnitude of the risk and transfusion requirements for MCSD patients at the time of transplantation have not been previously reported. The purpose of this study was to characterize and compare the bleeding characteristics and transfusion requirements of 3 sub-groups of cardiac transplant patients: primary (n = 45), redo (n = 26), and MCSD (n = 23) patients.

Implantation technique for the CardioWest total artificial heart.

The CardioWest total artificial heart is a pneumatically driven device that totally replaces the failing ventricles. It is currently undergoing clinical investigation as a bridge to heart transplantation in several centers throughout the world. A bilateral ventriculectomy is performed and the device is implanted. Blood flows are usually maintained at 6-8 L/min. Approximately 130 patients have undergone bridge to transplant with this device. Patient selection and excellent surgical technique are required for a successful outcome. A detailed description of the implantation technique is presented to facilitate the use of this technology.

Arizona experience with CardioWest Total Artificial Heart bridge to transplantation.

BACKGROUND: We hypothesized that bridge to transplantation with the CardioWest Total Artificial Heart would succeed in a large percentage of patients. Further, we hypothesized that this success rate would not be significantly decreased by infection or thromboembolism. METHODS: From 1993 to March 1999, 24 patients received implants with the intention of bridge to transplantation. Data were collected prospectively. Heparin, coumadin, aspirin, ticlopidine, dipyridamole, and pentoxifylline were used for anticoagulation. RESULTS: Four patients died while on device support. Nineteen of 23 patients (83%) were transplanted. All 19 survived long term. One patient remains on CardioWest Total Artificial Heart support 6 weeks after implant. There was one stroke on the day of transplantation. There was a second stroke on the day of implantation. Neither stroke caused significant residual deficits. Both were in close relationship to an operative procedure. There were no serious device-related infections. CONCLUSIONS: The CardioWest Total Artificial Heart salvaged 20 of 24 critically ill patients. Neither infections nor neurologic problems were significant. We believe it is the device of choice for decompensating patients with biventricular failure who have adequate body and heart size.

CardioWest total artificial heart: a retrospective controlled study.

The CardioWest total artificial heart (TAH) is a pneumatic device that is used as a bridge to heart transplantation and the only TAH available that totally replaces the failing ventricles. It has been utilized in selected centers in the U.S.A. with approval from the Food and Drug Administration. Strict criteria have been developed to select candidates to be bridged with the TAH. The patient must be a heart transplant candidate of age >18 and <59 years with a body surface area (BSA) > or = 1.7 m2, cardiac index (CI) <2.0 L/min/m2, and 2 inotropic agents or 1 plus an intraaortic balloon pump (IABP). A total of 24 heat transplant candidates (Group A) met the entry criteria and underwent placement of the TAH between January 1993 and July 1996. Group A consisted of 23 males; 16 patients had an IABP. The control group (Group B) consisted of 18 heart transplant candidates who met the TAH entry criteria but never received a TAH. Group B consisted of 15 males; 14 patients had an IABP. Preimplantation pulmonary vascular resistance (PVR) (Wood units), serum creatinine (mg/dl), and total bilirubin (mg/dl) were determined in both groups. The mean values for Groups A and B were, respectively, age: 47 and 47 years, BSA: 2.01 and 1.93 m2, CI: 1.5 and 1.8 L/min/m2, PVR: 2.88 and 2.47 Wood units, creatinine: 1.5 and 1.6 mg/dl, and bilirubin: 1.8 and 1.4 mg/dl. In Group A, 1 patient died on the TAH, 1 patient died after transplant, and 22 patients reached transplant and were discharged home for a survival rate of 91.7%. In Group B, 10 patients died while waiting for a heart transplant. Of the 8 patients transplanted, 7 survived and were discharged home for a survival rate of 38.9% (p = 0.0003). In summary the CardioWest TAH provided an excellent and successful method of bridging patients to heart transplantation with a reasonable risk.

Infections with the CardioWest total artificial heart.

The CardioWest total artificial heart is a pneumatically driven device that totally replaces the failing ventricles. It is currently used as a bridge to heart transplantation in selected centers in the United States under a study by the Food and Drug Administration. Twenty-seven patients have undergone placement of the total artificial heart since 1993 with the intention to bridge to transplantation. Inclusion criteria included candidacy for heart transplantation, cardiac index (CI) < 2.0 L/min/m2, and maximal inotropic support. The population consisted of 25 men and 2 women of mean +/- SD age 46.5 +/- 10.3 years, body surface area 2.01 +/- 0.17 m2, and duration of implant 52 +/- 42 days. Initial diagnosis included ischemic cardiomyopathy (n = 10), idiopathic (n = 10), viral (n = 4), valvular (n = 2), and graft failure (n = 1). Infectious complications were defined as systemic (evidence of leukocytosis or fever) or local. The population experienced 64 infections (range, 0-9 per patient): 45 systemic and 19 local. Three patients did not experience any infection. Twenty-five patients reached transplantation, and were discharged home for a survival rate of 92.6%. Two patients died during the bridge, one because of mechanical failure, and one because of infection (mediastinitis). Therefore, death attributable to infections occurred in 3.7%. Previous reports of the total artificial heart experience in the late 1980s described death rates as high as 40%. Although infectious complications are common in patients who are bridged to heart transplantation with the total artificial heart, mortality from infections is 10 times less than previously reported. This may be the result of a better strategy for bridging to transplantation that includes patient selection, mobilization, early central line removal, and waiting until all possible infections are resolved before proceeding to transplantation.

Positive panel reactive antibody titers in patients bridged to transplantation with a mechanical assist device: risk factors and treatment.

Patients who are bridged-to-transplantation with mechanical support have a high incidence of pretransplant sensitization defined by panel reactive antibody (PRA) titers greater than 10. Risk factors for positive PRA in patients with assist devices were investigated. From 1993 to 1997, 17 patients underwent implant surgery with CardioWest C-70 total artificial hearts (TAHs; CardioWest Technologies, Inc., Tucson, AZ), and 13 with Novacor left ventricular assist systems (LVASs; Baxter Healthcare, Novacor Division, Oakland, CA) for bridge-to-transplantation at this institution. Two patients died during implantation of the assist devices. Of the remaining 28 patients, four (14%) were women (3 with TAHs and 1 with an LVAS). All four women (100%) had a positive PRA, whereas only two of the 24 men (8%) had positive PRA (p < 0.0001). The transfusion histories of these patients were reviewed. Using chi-squared analysis (alpha = 0.05), the PRA levels were independent of transfusion of packed red blood cells and fresh frozen plasma. There was an association, however, between platelet transfusions and PRA levels. The times on device awaiting cardiac transplantation were also compared between the PRA positive and PRA negative groups. The average time to transplantation for PRA positive patients was 116 days, whereas the average waiting time for the PRA negative patients was 55 days (p = 0.05). Based on these data, a female patient with consistently positive PRA (93%) after TAH implantation underwent a transplant on post implant day 25 despite a positive lymphocytotoxic crossmatch with the donor. She was treated with plasmapheresis during cardiopulmonary bypass at the time of transplantation, and with four further treatments post transplant. As of this writing, she is alive and well on our standard triple immunotherapy. Therefore, women who are bridged-to-transplantation with assist devices are at risk for positive PRA. It is recommended that patients who are bridged-to-transplantation with assist devices and have high PRA levels be treated with perioperative plasmapheresis. With this aggressive approach, it may no longer be necessary to keep patients on mechanical support for prolonged periods, but possible to perform transplants as soon as suitable donors become available.

Endomyocardial biopsy in the heterotopic heart transplant patient.

We present a technique for rapid and easy endomyocardial biopsy of the heterotopic transplanted heart. With a recent resurgence in heterotopic heart transplantation, we believe that ours is a sound technique in obtaining both routine surveillance biopsies as well as evaluating "right-sided pressures" in the "piggy-back" heart.

Biventricular cannulation for the Thoratec ventricular assist device.

The Thoratec biventricular assist device has been used extensively as a bridge to heart transplantation. Right atrial cannulation has always been used during right ventricular support, however diminished filling and output of the right ventricular assist device have been noticed when compared with filling and output of the left ventricular assist device. We describe a technique to directly cannulate the right ventricle to maximize filling and output of the right ventricular assist device.

The CardioWest total artificial heart bridge to transplantation: 1993 to 1996 national trial.

BACKGROUND: We performed a controlled study of a total artificial heart in bridge to transplantation. We hypothesized that the CardioWest total artificial heart used in a selected population of decompensating cardiac transplantation candidates would result in improved survival compared with matched controls. METHODS: The CardioWest trial started in 1993 in six United States institutions under an investigational device exemption from the Food and Drug Administration. Four centers contributed 27 implant and 18 matched retrospective control patients. RESULTS: Of the implant patients, 25 (93%) received a transplant, 24 (89% of the total, 96% of those transplanted) were discharged and are currently surviving. In the control group, 10 patients died awaiting transplantation, 8 received a transplant, and 7 were discharged with 6 surviving (p = 0.00001). All adverse events were documented with respect to time. Thirteen serious adverse events occurred, 11 of which occurred in the 2 patients that died during implant. CONCLUSIONS: In a selected group of patients with endstage heart disease, use of the CardioWest total artificial heart is lifesaving. When compared with the series of matched retrospective controls, a significant improvement in survival was found in the CardioWest implant group.

International experience with the CardioWest total artificial heart as a bridge to heart transplantation.

As the number of potential heart donors remains constant and the number of potential recipients continuous to increase, the need for circulatory devices to bridge patients becomes more important. The CardioWest total artificial heart (TAH) is a pneumatic, implantable system that totally replaces the failing ventricles. It has been utilized worldwide as a bridge to heart transplantation in 79 patients. There were 73 males and six females who received the TAH. Currently three patients remain on the device waiting for transplantation. A total of 55 patients (70%) were transplanted of which 50 survived (91% of patients transplanted) and were discharged home. Idiopathic/dilated cardiomyopathy was the most common etiology followed by ischemic cardiomyopathy. The mean duration of implant was 34 days (range 0-186 days) and the mean age of the group was 45 years (range 16-62 years). Twenty-one patients died while on the device. Multiple organ failure was the major cause of death. There were a total of 255 complications in this group that included reoperation, bleeding, hepatic failure, renal failure, respiratory failure, neurologic events, thromboembolic events, infections, device malfunction, and fit complications. This represented a mean complication rate of three events per patient. The survival rate for the CardioWest TAH of 91% of the patients who reached transplantation is an improvement over that of the Symbion registry (55% of those transplanted) probably as a result of a better patient selection and better control of the coagulation system. These results are also comparable to those survival results obtained with other biventricular and left ventricular assist devices currently available.

Success rates of long-term circulatory assist devices used currently for bridge to heart transplantation.

Circulatory assist devices as bridge to heart transplantation have become more important as the number of possible recipients has increased and the number of donors remains stable. The number of patients successfully bridged and discharged home after transplantation was determined for the Novacor Left Ventricular Assist System (Baxter Healthcare Corp., Oakland, CA) (LVAS), console and wearable; the TCI Left Ventricular Assist Device (Thermo Cardio Systems Inc., Woburn, MA) (LVAD), pneumatic and electric; the Thoratec LVAD and Biventricular Assist Device (Thoratec Lab Co., Berkeley, CA) (BIVAD); and the CardioWest total artificial heart (CardioWest Tech. Inc., Tuscon, AZ) (TAH). A total of 1,286 devices (14% Novacor console, 14% Novacor wearable, 35% TCI pneumatic, 4% TCI electric, 10% thoratec LVAD, 19% Thoratec BIVAD, and 4% CardioWest TAH) were implanted worldwide since 1984. A total of 776 (60%) patients reached heart transplantation and 687 patients (88.5% of those transplanted) were discharged home. The individual success rate for each device to bridge a patient to heart transplantation and be discharged home is as follows: Novacor LVAS console, 90%; Novacor LVAS wearable, 92%; TCI LVAD pneumatic, 89%; TCI LVAD electric, 89%; Thoratec LVAD, 93%; Thoratec BIVAD, 81%; and CardioWest TAH, 92%. The success rate with all the available systems to bridge a patient to heart transplantation and be discharged home is similar for all devices. The criteria used to determine which system to be used should be individualized for each patient. Some of the factors that should be considered in making a decision on which device to use should include anticoagulation, univentricular vs biventricular failure, mobility, protocol to discharge home, and size of the patient.