Managing bilateral discontinuous pulmonary arteries of ductal origin in single ventricle anatomy.

BACKGROUND: We describe outcomes and management strategies for single ventricle and bilaterally discontinuous pulmonary arteries (PAs) originating from bilateral ductus arteriosus. METHODS: We reviewed 22 patients with aforementioned anatomy and PA centralization from 1995-2023, excluding those with biventricular repair. RESULTS: Median age at centralization was 9 days (range 0 days-2 years). Centralization was performed with systemic-to-pulmonary shunt (n=20, 91%; 2 following bilateral ductal stents) or bidirectional cavopulmonary connection (n=2, 9%) via pericardial roll (n=14, 64%), patch-augmented direct anastomosis (n=7, 32%), and interposition graft (n=1, 5%) techniques. Concurrent total anomalous pulmonary venous connection (TAPVC, n=11, 50%) was associated with significantly inferior survival (P=.01). Five patients (23%) died at a median of 59 (6-257) days post-centralization, all with non-cardiac TAPVC. At latest follow-up for 17 survivors (median 13.5 [0.5-25.1] years post-centralization), 12 completed Fontan, 4 completed second stage palliation, and 1 was transplanted prior to second stage palliation. Fourteen patients (64%) required PA reintervention, including 3 with reoperations independent of staged palliation. Baseline to pre-second stage echocardiography demonstrated branch PA growth with significantly increased diameters (left P=.0006, right P=.0002); z-scores significantly increased for right (P=.004) but not left (P=.11). CONCLUSIONS: Successful single ventricle palliation is possible, though high-risk, for patients with bilateral discontinuous ductal PAs. Early post-centralization mortality remains substantial, particularly with associated non-cardiac TAPVC. Many require reintervention to maintain PA growth, typically concurrently with staged palliation.

A prospective multicenter feasibility study of a miniaturized implantable continuous flow ventricular assist device in smaller children with heart failure.

BACKGROUND: There is no FDA-approved left ventricular assist device (LVAD) for smaller children permitting routine hospital discharge. Smaller children supported with LVADs typically remain hospitalized for months awaiting heart transplant-a major burden for families and a challenge for hospitals. We describe the initial outcomes of the Jarvik 2015, a miniaturized implantable continuous flow LVAD, in the NHLBI-funded Pumps for Kids, Infants, and Neonates (PumpKIN) study, for bridge-to-heart transplant. METHODS: Children weighing 8 to 30 kg with severe systolic heart failure and failing optimal medical therapy were recruited at 7 centers in the United States. Patients with severe right heart failure and single-ventricle congenital heart disease were excluded. The primary feasibility endpoint was survival to 30 days without severe stroke or non-operational device failure. RESULTS: Of 7 children implanted, the median age was 2.2 (range 0.7, 7.1) years, median weight 10 (8.2 to 20.7) kilograms; 86% had dilated cardiomyopathy; 29% were INTERMACS profile 1. The median duration of Jarvik 2015 support was 149 (range 5 to 188) days where all 7 children survived including 5 to heart transplant, 1 to recovery, and 1 to conversion to a paracorporeal device. One patient experienced an ischemic stroke on day 53 of device support in the setting of myocardial recovery. One patient required ECMO support for intractable ventricular arrhythmias and was eventually transplanted from paracorporeal biventricular VAD support. The median pump speed was 1600 RPM with power ranging from 1-4 Watts. The median plasma free hemoglobin was 19, 30, 19 and 30 mg/dL at 7, 30, 90 and 180 days or time of explant, respectively. All patients reached the primary feasibility endpoint. Patient-reported outcomes with the device were favorable with respect to participation in a full range of activities. Due to financial issues with the manufacturer, the study was suspended after consent of the eighth patient. CONCLUSION: The Jarvik 2015 LVAD appears to hold important promise as an implantable continuous flow device for smaller children that may support hospital discharge. The FDA has approved the device to proceed to a 22-subject pivotal trial. Whether this device will survive to commercialization remains unclear because of the financial challenges faced by industry seeking to develop pediatric medical devices. (Supported by NIH/NHLBI HHS Contract N268201200001I, clinicaltrials.gov 02954497).

Deactivation of LVAD Support for Myocardial Recovery - Surgical Perspectives.

Left ventricular assist devices (LVAD) are excellent therapies for advanced heart failure patients either bridged to transplant or for lifetime use. LVADs also allow for reverse remodeling of the failing heart that is often associated with functional improvement. Indeed, growing enthusiasm exists to better understand this population of patients whereby the LVAD is used as an adjunct to mediate myocardial recovery. When patients achieve benchmarks suggesting that they no longer need LVAD support, questions related to discontinuation of LVAD therapy become front and center. The purpose of this review is to provide a surgical perspective to the practical and technical issues surrounding LVAD deactivation.

Labyrinthine cor triatriatum sinister in fetal hypoplastic left heart syndrome is associated with poor outcomes.

OBJECTIVES: A subset of hypoplastic-left-heart-syndrome (HLHS) fetuses have a complex cor-triatriatum sinister that we named "labyrinthine-cor (L-cor)". We sought to determine the prevalence of L-cor in HLHS fetuses and hypothesized that it is associated with increased mortality. METHODS: This single-center retrospective cohort study included all HLHS fetuses from January 2010-December 2020. Fetuses with other hypoplastic-left-heart variants, inadequate images, lack of follow-up and fetal atrial-septal interventions were excluded. RAS was defined as the ratio of pulmonary-vein forward-to-reverse velocity-time-integral (VTI) ≤ 5 and severe-RAS defined as VTI-ratio <3. Kaplan-Meier survival-analysis was performed for the primary outcome of transplant-free survival for 62 weeks after gestational-age of 30 weeks (∼1 year). RESULTS: Of the 156 consecutive fetuses with HLHS, 11 (7.7%) had L-cor and 8/11 (72.7%) of these had RAS. When compared to HLHS-RAS without L-cor, fetuses with HLHS-RAS and L-cor were less likely to survive to 28 days (87% vs. 62.5%, p = 0.017) and to 1 year (69.6% vs. 25%, p = 0.029). When comparing by survival analysis, fetuses with severe-RAS with L-cor had lower survival compared severe-RAS without L-cor (p = 0.020). CONCLUSION: L-cor in fetal HLHS is associated with increased mortality. Recognition of this finding is important for prognostication and atrial-septal-intervention planning.

Activated fibroblasts drive cellular interactions in end-stage pediatric hypertrophic cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is a relatively rare but debilitating diagnosis in the pediatric population and patients with end-stage HCM require heart transplantation. In this study, we performed single-nucleus RNA sequencing on pediatric HCM and control myocardium. We identified distinct underling cellular processes in pediatric, end-stage HCM in cardiomyocytes, fibroblasts, endothelial cells, and myeloid cells, compared to controls. Pediatric HCM was enriched in cardiomyocytes exhibiting "stressed" myocardium gene signatures and underlying pathways associated with cardiac hypertrophy. Cardiac fibroblasts exhibited clear activation signatures and heightened downstream processes associated with fibrosis, more so than adult counterparts. There was notable depletion of tissue-resident macrophages, and increased vascular remodeling in endothelial cells. Our analysis provides the first single nuclei analysis focused on end-stage pediatric HCM.

The Macrophage Landscape Across the Lifespan of a Human Cardiac Allograft.

BACKGROUND: Much of our knowledge of organ rejection after transplantation is derived from rodent models. METHODS: We used single-nucleus RNA sequencing to investigate the inflammatory myocardial microenvironment in human pediatric cardiac allografts at different stages after transplantation. We distinguished donor- from recipient-derived cells using naturally occurring genetic variants embedded in single-nucleus RNA sequencing data. RESULTS: Donor-derived tissue resident macrophages, which accompany the allograft into the recipient, are lost over time after transplantation. In contrast, monocyte-derived macrophages from the recipient populate the heart within days after transplantation and form 2 macrophage populations: recipient MP1 and recipient MP2. Recipient MP2s have cell signatures similar to donor-derived resident macrophages; however, they lack signatures of pro-reparative phagocytic activity typical of donor-derived resident macrophages and instead express profibrotic genes. In contrast, recipient MP1s express genes consistent with hallmarks of cellular rejection. Our data suggest that recipient MP1s activate a subset of natural killer cells, turning them into a cytotoxic cell population through feed-forward signaling between recipient MP1s and natural killer cells. CONCLUSIONS: Our findings reveal an imbalance of donor-derived and recipient-derived macrophages in the pediatric cardiac allograft that contributes to allograft failure.

Single nucleus transcriptome of a "Super RV" shows increased insulin and angiogenesis signaling.

The right ventricle (RV) is one of the four pumping chambers of the heart, pumping blood to the lungs. In severe forms of congenital heart disease and pulmonary hypertension, the RV is made to pump into the systemic circulation. Such systemic RVs typically display early failure due to pressure overload. In rare cases a systemic RV persists into later decades of life - colloquially called a 'Super RV'. Here we present the single-nucleus transcriptome of a systemic RV from a 60-year-old with congenitally corrected transposition of great arteries (ccTGA). Our data shows two specific signaling pathways enriched in the ccTGA RV myocardium. First, we show increased insulin like growth factor (IGF1) signaling within the systemic RV myocardium: there is increased expression of the main receptor IGFR1 within the cardiomyocytes, and IGF1 ligands within the cardiofibroblasts and macrophages. Second, we find increased VEGF and Wnt9 ligand expression in cardiomyocytes and increased VEGF1R and Wnt9 receptors in endothelial cells, which are implicated in angiogenesis. We show that increased insulin and angiogenesis signaling are potentially beneficial RV adaptations to increased pressure overload. This study of an adult systemic RV provides an important framework for understanding RV remodeling to systemic pressures in congenital heart disease and pulmonary hypertension.

Clinical Presentation, Classification, and Outcomes of Cardiogenic Shock in Children.

BACKGROUND: Despite growing cardiogenic shock (CS) research in adults, the epidemiology, clinical features, and outcomes of children with CS are lacking. OBJECTIVES: This study sought to describe the epidemiology, clinical presentation, hospital course, risk factors, and outcomes of CS among children hospitalized for acute decompensated heart failure (ADHF). METHODS: We examined consecutive ADHF hospitalizations (<21 years of age) from a large single-center retrospective cohort. Patients with CS at presentation were analyzed and risk factors for CS and for the primary outcome of in-hospital mortality were identified. A modified Society for Cardiovascular Angiography and Interventions shock classification was created and patients were staged accordingly. RESULTS: A total of 803 hospitalizations for ADHF were identified in 591 unique patients (median age 7.6 years). CS occurred in 207 (26%) hospitalizations. ADHF hospitalizations with CS were characterized by worse systolic function (P = 0.040), higher B-type natriuretic peptide concentration (P = 0.032), and more frequent early severe renal (P = 0.023) and liver (P < 0.001) injury than those without CS. Children presenting in CS received mechanical ventilation (87% vs 26%) and mechanical circulatory support (45% vs 16%) more frequently (both P < 0.001). Analyzing only the most recent ADHF hospitalization, children with CS were at increased risk of in-hospital mortality compared with children without CS (28% vs 11%; OR: 1.91; 95% CI: 1.05-3.45; P = 0.033). Each higher CS stage was associated with greater inpatient mortality (OR: 2.40-8.90; all P < 0.001). CONCLUSIONS: CS occurs in 26% of pediatric hospitalizations for ADHF and is independently associated with hospital mortality. A modified Society for Cardiovascular Angiography and Interventions classification for CS severity showed robust association with increasing mortality.

Long-term implantable ventricular assist device support in children.

BACKGROUND: In pediatrics, implantable continuous-flow ventricular assist devices (IC-VAD) are often used as a "temporary" support, bridging children to cardiac transplantation during the same hospital admission. METHODS: We conducted a retrospective review of our consecutive patients undergoing IC-VAD support at a tertiary pediatric heart center between 2008 and 2022. RESULTS: We identified 100 IC-VAD implant encounters: HeartWare HVAD (67; 67%), HeartMate II (17; 17%), and HeartMate 3 (16; 16%). The median (range) age, weight, and body surface area at implantation were 14.1 (3.0-56.5) years, 54.8 (13.3-140) kg, and 1.6 (0.6-2.6) m2, respectively. Cardiomyopathy (58; 58%) was the most common etiology, followed by congenital heart disease (37; 37%, including 13 single ventricle). At 6 months of IC-VAD support, 94 (94%) encounters achieved positive outcomes: ongoing support (59; 59%), transplant (33; 33%), and cardiac recovery (2; 2%). Eighty-two encounters (82%) resulted in home discharge with ongoing VAD support, including 38 (46%, out of 82) requiring readmission and 7 (9%, out of 82) resulting in death. There was a clinically significant decrease in morbidity rates before versus after home discharge: bleeding (1.55 vs 0.06), infection (0.84 vs 0.37), and stroke (0.84 vs 0.15 event per patient-year). Overall, 86 encounters (86%) reached positive end points at the latest follow-up (64 transplant, 15 ongoing support, and 7 recovery). Infection (29%; 4 of 14) was the most common cause of negative outcomes, followed by cerebrovascular accident (21%; 3), and unresolved frailty (21%; 3). The estimated overall survival at 1, 2, and 5 years was 90%, 86%, and 77%, respectively. CONCLUSIONS: This study suggests the feasibility of outpatient management of pediatric IC-VAD support. The ability to offer true long-term support maximizes the potential of IC-VAD support, not limited to a temporary bridging tool for heart transplantation.

Long-term kidney outcomes in pediatric continuous-flow ventricular assist device patients.

BACKGROUND: Continuous-flow ventricular assist devices (CF-VADs) are used increasingly in pediatric end-stage heart failure (ESHF) patients. Alongside common risk factors like oxidant injury from hemolysis, non-pulsatile flow constitutes a unique circulatory stress on kidneys. Post-implantation recovery after acute kidney injury (AKI) is commonly reported, but long-term kidney outcomes or factors implicated in the evolution of chronic kidney disease (CKD) with prolonged CF-VAD support are unknown. METHODS: We studied ESHF patients supported > 90 days on CF-VAD from 2008 to 2018. The primary outcome was CKD (per Kidney Disease Improving Global Outcomes (KDIGO) criteria). Secondary outcomes included AKI incidence post-implantation and CKD evolution in the 6-12 months of CF-VAD support. RESULTS: We enrolled 134 patients; 84/134 (63%) were male, median age was 13 [IQR 9.9, 15.9] years, 72/134 (54%) had preexisting CKD at implantation, and 85/134 (63%) had AKI. At 3 months, of the 91/134 (68%) still on a CF-VAD, 34/91 (37%) never had CKD, 13/91 (14%) developed de novo CKD, while CKD persisted or worsened in 49% (44/91). Etiology of heart failure, extracorporeal membrane oxygenation use, duration of CF-VAD, AKI history, and kidney replacement therapy were not associated with different CKD outcomes. Mortality was higher in those with AKI or preexisting CKD. CONCLUSIONS: In the first multicenter study to focus on kidney outcomes for pediatric long-term CF-VAD patients, preimplantation CKD and peri-implantation AKI were common. Both de novo CKD and worsening CKD can happen on prolonged CF-VAD support. Proactive kidney function monitoring and targeted follow-up are important to optimize outcomes.

Seventh Annual Society of Thoracic Surgeons Pedimacs Report.

BACKGROUND: The Pediatric Interagency Registry for Mechanical Circulatory Support (Pedimacs), supported by The Society of Thoracic Surgeons, provides detailed information on pediatric patients supported with ventricular assist devices (VADs). METHODS: From September 19, 2012, to December 31, 2022, 1463 devices in 1219 patients aged <19 years were reported to the registry from 40 North American hospitals. RESULTS: Cardiomyopathy remains the most common underlying etiology (59%), followed by congenital heart disease (26%) and myocarditis (8%). Implantable continuous devices were most common (39%) type, followed by paracorporeal pulsatile (28%) and paracorporeal continuous (27%) devices. At 6 months after VAD implantation, a favorable outcome (transplant, recovery, or alive on device) was achieved in 85% of patients, which was greatest among those on implantable continuous VADs (92%) and least for paracorporeal continuous VADs (68%), although the patient population supported on these devices is different. CONCLUSIONS: This Seventh Pedimacs Report demonstrates the continued importance of VADs in the treatment of children. With the complexity of cardiac physiologies and sizes of patients, multiple types of devices are used, including paracorporeal continuous, paracorporeal pulsatile, and implantable continuous devices. The preoperative risk factors and differences in patient populations may account for some of the differences in survival observed among these devices. This report, along with other collaborative work, continues to advance the care of this challenging and vulnerable population.

Endothelial cells adopt a pro-reparative immune responsive signature during cardiac injury.

Modulation of the heart's immune microenvironment is crucial for recovery after ischemic events such as myocardial infarction (MI). Endothelial cells (ECs) can have immune regulatory functions; however, interactions between ECs and the immune environment in the heart after MI remain poorly understood. We identified an EC-specific IFN responsive and immune regulatory gene signature in adult and pediatric heart failure (HF) tissues. Single-cell transcriptomic analysis of murine hearts subjected to MI uncovered an EC population (IFN-ECs) with immunologic gene signatures similar to those in human HF. IFN-ECs were enriched in regenerative-stage mouse hearts and expressed genes encoding immune responsive transcription factors (Irf7, Batf2, and Stat1). Single-cell chromatin accessibility studies revealed an enrichment of these TF motifs at IFN-EC signature genes. Expression of immune regulatory ligand genes by IFN-ECs suggests bidirectional signaling between IFN-ECs and macrophages in regenerative-stage hearts. Our data suggest that ECs may adopt immune regulatory signatures after cardiac injury to accompany the reparative response. The presence of these signatures in human HF and murine MI models suggests a potential role for EC-mediated immune regulation in responding to stress induced by acute injury in MI and chronic adverse remodeling in HF.

Comparing palliation strategies for single-ventricle anatomy with transposed great arteries and systemic outflow obstruction.

Objective: Patients with complex single-ventricle anatomy with transposed great arteries and systemic outflow obstruction (SV-TGA-SOO) undergo varied initial palliation with ultimate goal of Fontan circulation. We examine a longitudinal experience with multiple techniques, including the largest published cohort following palliative arterial switch operation (pASO), to describe outcomes and decision-making factors. Methods: Neonates with SV-TGA-SOO who underwent initial surgical palliation from 1995 to 2022 at a single institution were retrospectively reviewed. Results: In total, 71 neonates with SV-TGA-SOO underwent index surgical palliation at a median age of 7 days (interquartile range, 6-10) by pASO (n = 23), pulmonary artery band (PAB) with or without arch repair (n = 25), or modified Norwood with Damus-Kaye-Stansel aortopulmonary amalgamation (n = 23). Single-ventricle pathology included double-inlet left ventricle (n = 37, 52%), tricuspid atresia (n = 27, 38%), and others (n = 7, 10%). All mortalities (n = 5, 7%) occurred in the first interstage period after PAB (n = 3) and Norwood (n = 2). Subaortic obstruction in the PAB group was addressed by operative resection (n = 10 total, 7 at index operation) and/or delayed aortopulmonary amalgamation (n = 13, 52%). Two patients with pASO (9%) had early postoperative coronary complications, 1 requiring operative revision. Median follow-up for survivors was 10.4 years (interquartile range, 4.5-16.6 years). Comparing patients by their initial palliation type, notable significant differences included size of bulboventricular foramen, weight at initial operation, operation duration, postoperative length of stay, time to second-stage palliation, multiple pulmonary artery reinterventions, and left pulmonary artery interventions. There were no significant differences in overall survival, Fontan completion, reintervention-free survival in the first interstage period, pulmonary artery reintervention-free survival, long-term systemic valve competency, or ventricular dysfunction. Conclusions: Excellent mid- to long-term outcomes are achievable following neonatal palliation for SV-TGA-SOO via pASO, PAB, and modified Norwood, with comparable survival and Fontan completion. Initial palliation strategy should be individualized to optimize anatomy and physiology for successful Fontan by ensuring an unobstructed subaortic pathway and accessible pulmonary arteries. pASO is a reasonable strategy to consider for these heterogeneous lesions.

Survival in Pediatric Patients With Ventricular Assist Devices: A Special Pediatric Interagency Registry for Mechanical Circulatory Support (Pedimacs) Report.

BACKGROUND: The Pediatric Interagency Registry for Mechanical Circulatory Support (Pedimacs) provides detailed understanding on pediatric patients supported with ventricular assist devices (VADs). We sought to identify important variables affecting mortality in pediatric VADs. METHODS: Patients aged <19 years, from 2012 to 2021, were included. Survival analyses were performed using Kaplan-Meier. Parametric hazard modeling was used to identify risk factors for death. RESULTS: Of the 1109 patients, the most common devices were implantable continuous (IC, 448 [40%]), followed by paracorporeal pulsatile (PP, 306 [28%]), paracorporeal continuous (PC, 293 [26%]), and percutaneous (58 [5%]). Patients with percutaneous device, infants, congenital heart disease, biventricular support, and Interagency Registry for Mechanically Assisted Circulatory Support profile 1 had worse overall survival at 6 months. Positive outcome was 83% at 6 months. Consistent with their cohort composition, device type positive outcomes at 6 months were IC, 92%; PP, 84%; and PC, 69%. Parametric hazard modeling for overall survival showed an early hazard for death with biventricular support, congenital heart disease (CHD), intubation before implantation, PC device, and renal impairment, whereas a constant hazard was associated with ascites. For patients <10 kg, parametric modeling showed an early hazard for CHD, intubation, and renal impairment. Modeling in CHD patients showed an early hazard for biventricular support, renal impairment, and use of PC/PP devices. CONCLUSIONS: This multivariable analysis of the complete Pedimacs database demonstrates that illness at VAD implantation, diagnosis, and strategy of support affect survival and differ by device type. We hope this is the first step in creating a predictive tool to help providers and families have informed expectations.

Taking ACTION: A Prognostic Tool for Pediatric Ventricular Assist Device Mortality.

We sought to develop a contemporary risk assessment tool for use in pediatric ventricular assist device (VAD) candidates to estimate risk for mortality on the device using readily available preimplantation clinical data. Training and testing datasets were created from Advanced Cardiac Therapies Improving Outcomes Network (ACTION) registry data on patients supported with a VAD from 2012 to 2021. Potential risk factors for mortality were assessed and incorporated into a simplified risk prediction model utilizing an open-source, gradient-boosted decision tree machine learning library, known as random forest. Predictive performance was assessed by the area under the receiver operating characteristic curve in the testing dataset. Nine significant risk factors were included in the final predictive model which demonstrated excellent discrimination with an area under the curve of 0.95. In addition to providing a framework for establishing pediatric-specific risk profiles, our model can help inform team expectations, guide optimal patient selection, and ultimately improve patient outcomes.

Continuous-Flow Ventricular Assist Device Support in Adult Congenital Heart Disease: A 15-Year, Multicenter Experience of Temporary and Durable Support.

Heart failure (HF) is common in adult congenital heart disease (ACHD) patients; however, use of continuous-flow ventricular assist devices (CF-VADs) remains rare. We reviewed outcomes of patients with congenital heart disease greater than or equal to 18 years of age at the time of CF-VAD implant at the affiliated pediatric and adult institutions between 2006 and 2020. In total, 18 ACHD patients (15 with great anatomical complexity) received 21 CF-VADs. Six patients (median age 34 years) received seven percutaneous CF-VADs with a median duration of support of 20 days (3-44 days) with all patients survived to hospital discharge and two patients were bridged to durable CF-VADs. Fourteen patients (median age 38 years) received durable CF-VADs. Thirteen patients (93%) survived to hospital discharge and the median duration of support was 25.8 months (6.4-52.1 months). Estimated survival on durable CF-VAD at 1, 3, and 5 years was 84%, 72%, and 36%, respectively. Three patients were successfully bridged to transplantation. Device-related complications include cerebrovascular accident (n = 5), driveline infection (n = 3), device infection requiring chronic antibiotic therapy (n = 4), gastrointestinal bleeding (n = 6), and presumed pump thrombosis (n = 5). These results show percutaneous and durable CF-VADs can support ACHD patients with advanced HF.

Temporary ventricular assist device support with a catheter-based axial pump: Changing the paradigm at a pediatric heart center.

OBJECTIVE: We report the largest pediatric single-center experience with an Impella (Abiomed Inc) catheter-based axial pump support. METHODS: We conducted a retrospective cohort study of all patients with acute decompensated heart failure or cardiogenic shock requiring catheter-based axial pump support between October 2014 and February 2022. The primary outcome per individual encounter (hospital admission) was defined as bridge-to-recovery, bridge-to-durable ventricular assist device support, bridge-to-cardiac transplantation, or death at 6 months after catheter-based axial pump explantation. Adverse events were defined according to the Pediatric Interagency Registry for Mechanical Circulatory Support criteria. RESULTS: Our final study cohort included 37 encounters with 43 catheter-based axial pump implantations. A single catheter-based axial pump device was used for support in 33 encounters (89%), with 2 catheter-based axial pump devices used in 3 (8%) separate encounters and 3 catheter-based axial pump devices used in 1 (3%) encounter. The median [range] age, weight, and body surface area at implantation were 16.8 [6.9-42.8] years, 61.1 [23.1-123.8] kg, and 1.7 [0.8-2.5] m2, respectively. The predominant causes of circulatory failure were graft failure/rejection in 16 patients (43%), followed by cardiomyopathy in 7 patients (19%), arrhythmia refractory to medical therapies in 6 patients (16%), myocarditis/endocarditis in 4 patients (11%), and heart failure due to congenital heart disease in 4 patients (11%). Competing outcomes analysis showed a positive outcome with bridge-to-recovery in 58%, bridge-to-durable VAD support in 14%, and bridge-to-cardiac transplantation in 14% at 6 months. Fourteen percent of encounters resulted in death at 6 months. CONCLUSIONS: We demonstrate that catheter-based axial pump support in children results in excellent 1- and 6-month survival with an acceptable adverse event profile.

Ventricular assist device support for failing Glenn circulation: Impact of concomitant Fontan completion in select patients.

BACKGROUND: Ventricular assist device (VAD) support for failing Glenn circulation represents a unique challenge. METHODS: We conducted a retrospective review of clinical outcomes in patients with VAD support for failing Glenn circulation between 2010 and 2020 at a tertiary pediatric institution. RESULTS: Ten patients were included: INTERMACS profiles were 1 in 3 patients and 2 in 7 patients. The median age, weight, and body surface area were 3.2 years, 13.0 kg, and 0.5 m2, respectively. Seven patients (70%) were implanted with continuous-flow devices and 3 with para-corporeal devices. Nine patients (90%) received heart transplant, with a median support duration of 77 days. Four (67%) out of 6 patients supported with discharge-capable devices were managed as outpatients. Post-transplant survival was 100%, with a median (range) follow up duration of 3.5 (1.8-11.9) years. There were 3 neurologic complications in 3 patients (0.9 events per patient-year); 2 intraoperative events (fatal hypoxia and symptomatic embolic stroke) and 1 postoperative (asymptomatic subarachnoid hemorrhage). Pump thrombosis occurred in one patient (0.3 events per patient-year), requiring pump exchange at day 65. Five patients (50%) received concomitant Fontan completion (fenestrated in 1). The Fontan-upgraded patients (vs Glenn) tended to be larger (median (range): 15.9 (12.6-22.9) vs 9.1 (7.7-22.8) kg), older (4.7 (3.1-6.5) vs 1.1 (0.9-10.1) years) and had a higher PaO2/FiO2 ratio (192 (52-336) vs 76 (59-78) mm Hg) on postoperative day 1. CONCLUSION: Our experience suggests the feasibility of durable VAD support for failing Glenn circulation. Concomitant Fontan completion may be considered in select patients to improve oxygen delivery.