Implantable Cardioverter Defibrillators in Infants and Toddlers: Indications, Placement, Programming, and Outcomes.

BACKGROUND: Limited data exist regarding implantable cardioverter defibrillator (ICD) usage in infants and toddlers. This study evaluates ICD placement indications, procedural techniques, programming strategies, and outcomes of ICDs in infants and toddlers. METHODS: This is a single-center retrospective review of all patients ≤3 years old who received an ICD from 2009 to 2021. RESULTS: Fifteen patients received an ICD at an age of 1.2 years (interquartile range [IQR], 0.1-2.4; 12 [80%] women; weight, 8.2 kg [IQR, 4.2-12.6]) and were followed for a median of 4.28 years (IQR, 1.40-5.53) or 64.2 patient-years. ICDs were placed for secondary prevention in 12 patients (80%). Diagnoses included 8 long-QT syndromes (53%), 4 idiopathic ventricular tachycardias/ventricular fibrillations (VFs; 27%), 1 recurrent ventricular tachycardia with cardiomyopathy (7%), 1 VF with left ventricular noncompaction (7%), and 1 catecholaminergic polymorphic ventricular tachycardia (7%). All implants were epicardial, with a coil in the pericardial space. Intraoperative defibrillation safety testing was attempted in 11 patients (73%), with VF induced in 8 (53%). Successful restoration of sinus rhythm was achieved in all tested patients with a median of 9 (IQR, 7.3-11.3) J or 0.90 (IQR, 0.68-1.04) J/kg. Complications consisted of 1 postoperative chylothorax and 3 episodes of feeding intolerance. VF detection was programmed to 250 (IQR, 240-250) ms with first shock delivering 10 (IQR, 5-15) J or 1.1 (IQR, 0.8-1.4) J/kg. Three patients (20%) received appropriate shocks for ventricular tachycardia/VF. No patient received an inappropriate shock. There were 2 (13%) ventricular lead fractures (at 2.6 and 4.2 years post-implant), 1 (7%) pocket-site infection, and 2 (13%) generator exchanges. All patients were alive, and 1 patient (7%) received a heart transplant. CONCLUSIONS: ICDs can be safely and effectively placed for sudden death prevention in infants and toddlers with good midterm outcomes.

Single Ventricular Assist Device Support for the Failing Bidirectional Glenn Patient.

BACKGROUND: Given poor outcomes, strategies to improve ventricular assist devices (VADs) for single-ventricle patients with bidirectional Glenn (BDG) palliation are needed. METHODS: This retrospective review describes an institutional experience with VAD support for patients with BDG from April 2011 to January 2019. Surgical strategies, complications, and causes of death are described. Survival to heart transplantation for various strategies are compared. RESULTS: A total of 7 patients with BDG (weights, 5.6 to 28.8 kg; ages, 7 months to 11 years) underwent VAD implantation. Three patients underwent implantation of Berlin Heart EXCOR devices (Berlin Heart, Inc, Spring, TX), 2 had HeartWare HVADs (Medtronic, Minneapolis, MN) implanted, and 2 patients underwent implantation of paracorporeal continuous flow devices. Four patients underwent ventricular inflow cannulation, and 3 underwent atrial inflow cannulation. At the time of VAD implantation, the BDG was left intact in 3 patients, taken down in 3 patients, and created de novo in 1 patient. Over a total of 420 VAD support days, 2 patients survived to heart transplantation, 1 patient with HeartWare ventricular cannulation and intact BDG (after 174 days) and another with Berlin Heart atrial cannulation and BDG take-down (after 72 days). There were 3 deaths within 2 weeks of VAD implantation (2 from respiratory failure, 1 from infection) and 2 deaths after 30 days as a result of strokes. CONCLUSIONS: The surgical strategy and postoperative management of VAD with BDG are still evolving. Successful support can be achieved with (1) both pulsatile and continuous flow pumps, (2) atrial or ventricular cannulation, and (3) with or without BDG take-down. Surgical strategy should be determined by individual patient anatomy, physiology, and condition.

Bridge to Transplant with Ventricular Assist Device Support in Pediatric Patients with Single Ventricle Heart Disease.

Ventricular assist device (VAD) support for children with single ventricle (SV) heart disease remains challenging. We performed a single-center retrospective review of SV patients on VAD support and examined survival to transplant using the Kaplan-Meier method. Patients transplanted were compared with those who died on support. Between 2009 and 2017, there were 14 SV patients with 1,112 patient-days of VAD support. Stages of palliation included pre-Glenn (n = 5), Glenn (n = 5), and Fontan (n = 4). Eight patients (57%) were successfully bridged to transplant at a median 107 days. Deaths occurred early (n = 6, median 16 days) and in smaller patients (10.1 vs. 28.3 kg, P = 0.04). All Fontan patients survived to transplant, whereas only 20% of Glenn patients survived to transplant. Adverse events occurred in 79% (n = 11). Five patients met hospital discharge criteria, with two patients (one pre-Glenn, one Glenn) discharged and transplanted after 219 and 174 days of VAD support. All transplanted patients were discharged at a median 21 days posttransplant. SV patients in various stages of palliation can be successfully bridged to transplant with VAD support. With use of intracorporeal continuous-flow devices, longer-term support and hospital discharge are possible.

Aortic or Pulmonary Valved Homograft Right Ventricle to Pulmonary Artery Conduit in the Norwood Procedure.

BACKGROUND: Several modifications of the Norwood procedure utilizing valved right ventricle to pulmonary artery conduits have recently been reported. Our group has been using aortic or pulmonary valved homografts combined with PTFE tube grafts for now 16 years. METHODS: In this report, we review our technique in detail and describe any changes that have occurred over the years. We provide detailed illustrations of our preferred surgical technique, report outcome data, and compare it to the other conduit options available. RESULTS: Between 2006 and 2015, 130 stage I Norwood procedures were performed at our institution, 100 of them using valved conduits. Our technique is described and illustrated in detail. Early mortality was 15%. Postoperative percutaneous intervention on the conduit was required in 29% of cases. CONCLUSIONS: While a randomized trial comparing different valved conduits is lacking, we believe a composite conduit made from homograft aortic or pulmonary valves and PTFE tube grafts is an excellent choice in stage I Norwood procedure.

Patient-Specific Multiscale Modeling of the Assisted Bidirectional Glenn.

BACKGROUND: First-stage palliation of neonates with single-ventricle physiology is associated with poor outcomes and challenging clinical management. Prior computational modeling and in vitro experiments introduced the assisted bidirectional Glenn (ABG), which increased pulmonary flow and oxygenation over the bidirectional Glenn (BDG) and the systemic-to-pulmonary shunt in idealized models. In this study, we demonstrate that the ABG achieves similar performance in patient-specific models and assess the influence of varying shunt geometry. METHODS: In a small cohort of single-ventricle prestage 2 patients, we constructed three-dimensional in silico models and tuned lumped parameter networks to match clinical measurements. Each model was modified to produce virtual BDG and ABG surgeries. We simulated the hemodynamics of the stage 1 procedure, BDG, and ABG by using multiscale computational modeling, coupling a finite-element flow solver to the lumped parameter network. Two levels of pulmonary vascular resistances (PVRs) were investigated: baseline (low) PVR of the patients and doubled (high) PVR. The shunt nozzle diameter, anastomosis location, and shape were also manipulated. RESULTS: The ABG increased the pulmonary flow rate and pressure by 15% to 20%, which was accompanied by a rise in superior vena caval pressure (2 to 3 mm Hg) at both PVR values. Pulmonary flow rate and superior vena caval pressures were most sensitive to the shunt nozzle diameter. CONCLUSIONS: Patient-specific ABG performance was similar to prior idealized simulations and experiments, with good performance at lower PVR values in the range of measured clinical data. Larger shunt outlet diameters and lower PVR led to improved ABG performance.

Characteristics of deposits and pump exchange in the Berlin Heart EXCOR ventricular assist device: Experience with 67 cases.

Pump exchanges are frequently required in the Berlin Heart EXCOR VAD. We intended to describe the characteristics of pump deposits in a larger patient series and evaluate if changes in our exchange procedure over time have led to increased complications. We reviewed all EXCOR pump exchanges in our institution from July 2004 to October 2014. We gathered data on size and location of pump deposits and exchange procedures. EXCOR devices were implanted in 38 children. Support was LVAD only in 22, BiVAD in 13, and SVAD in 3 cases. Sixty-seven pumps were exchanged. The incidence of pump exchanges per month was higher for smaller pumps and for RVADs vs LVADs. Indications were visible pump deposit in 55, stroke without visible deposit in 5, incorporation of membrane oxygenator in 3, pump size change in 2, and sepsis in 1 case, respectively. Deposits were located in the outflow valve in 73%, inflow valve in 22%, pump body in 3%, and outflow cannula in 3%. EXCOR pumps are predominantly exchanged for deposits, which are most frequently located in the outflow valves. The procedure is now carried out without sedation at the bedside. No major complications were observed during exchanges.

Ventricular Assist Devices for Neonates and Infants.

Heart transplant waitlist survival in pediatric patients has been substantially improved since the introduction of pediatric-specific ventricular assist device. In neonates and infants, however, the waitlist mortality remains very high. The only long-term device currently approved for use in the United States is the Berlin Heart EXCOR, but this device has several important limitations because of the paracorporeal, pulsatile nature of the underlying technology. We reviewed Stanford ventricular assist experience on patients less than 1 year old since 2004. It shows overall 1-, 3-, and 5-year survival were 68%, 62%, and 49%, respectively. There are statistically significant differences in survival among cardiomyopathy group, end-stage congenital heart disease group and single ventricle group. In order to improve outcomes in this extremely high risk group, modifications were made to anticoagulation protocols, cannulation strategy in hypertrophic cardiomyopathy patients, and preferential use of continuous flow pumps in a single ventricle patients. The long-waited PumpKIN trial testing the Jarvik 2015 is about to start with the first human implant.

Effect of Inhaled Nitric Oxide on Hemodynamics in Lambs with 1½ Ventricle Circulation.

Inhaled nitric oxide (NO) is widely used to treat postoperative pulmonary hypertension in congenital heart disease. It is believed that NO increases cardiac output (CO) by decreasing pulmonary vascular resistance (PVR), leading to increased left ventricular preload. However, the effect of NO on CO in patients with 1½ ventricle circulation remains unclear. To evaluate this, a superior cavopulmonary (SCP) shunt was constructed in 10 juvenile sheep. A PTFE graft was inserted between the superior vena cava (SVC) and the main pulmonary artery (PA). The SVC was clamped at the right atrial junction to establish a 1½ ventricle circulation. Flows, pressures, and arterial blood gases were recorded before and during inhalation of NO. Mean arterial pressure (46.6 ± 5.4 to 44.6 ± 5.9 mm Hg; p = 0.06) and left atrial pressure (4.0 ± 2.5 to 4.0 ± 2.3 mm Hg; p = 1.0) did not change. Mean PA pressure (13.6 ± 2.4 to 11.7 ± 2.9 mm Hg; p = 0.006) and PVR (5.47 ± 2.99 to 4.54 ± 2.61 Wood Units; p = 0.037) decreased significantly. SVC flow (24.8 ± 11.3 to 22.0 ± 9.7 ml/min/kg; p = 0.09) did not change, and CO decreased (140.2 ± 37.2 to 132.1 ± 39.2 ml/min/kg; p = 0.033). Arterial PO2 improved (103.72 ± 29.30 to 132.43 ± 47.02 mm Hg; p = 0.007). In this 1½ ventricle model, NO surprisingly decreased cardiac output (CO) and did not increase left ventricular preload.

Interstage evaluation of homograft-valved right ventricle to pulmonary artery conduits for palliation of hypoplastic left heart syndrome.

OBJECTIVE: Palliation of hypoplastic left heart syndrome with a standard nonvalved right ventricle to pulmonary artery conduit results in an inefficient circulation in part due to diastolic regurgitation. A composite right ventricle pulmonary artery conduit with a homograft valve has a hypothetical advantage of reducing regurgitation, but may differ in the propensity for stenosis because of valve remodeling. METHODS: This retrospective cohort study included 130 patients with hypoplastic left heart syndrome who underwent a modified stage 1 procedure with a right ventricle to pulmonary artery conduit from 2002 to 2015. A composite valved conduit (cryopreserved homograft valve anastomosed to a polytetrafluoroethylene tube) was placed in 100 patients (47 aortic, 32 pulmonary, 13 femoral/saphenous vein, 8 unknown), and a nonvalved conduit was used in 30 patients. Echocardiographic functional parameters were evaluated before and after stage 1 palliation and before the bidirectional Glenn procedure, and interstage interventions were assessed. RESULTS: On competing risk analysis, survival over time was better in the valved conduit group (P = .040), but this difference was no longer significant after adjustment for surgical era. There was no significant difference between groups in the cumulative incidence of bidirectional Glenn completion (P = .15). Patients with a valved conduit underwent more interventions for conduit obstruction in the interstage period, but this difference did not reach significance (P = .16). There were no differences between groups in echocardiographic parameters of right ventricle function at baseline or pre-Glenn. CONCLUSIONS: In this cohort of patients with hypoplastic left heart syndrome, inclusion of a valved right ventricle to pulmonary artery conduit was not associated with any difference in survival on adjusted analysis and did not confer an identifiable benefit on right ventricle function.

Temporary Circulatory Support in U.S. Children Awaiting Heart Transplantation.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) has long served as the standard of care for short-term mechanical circulatory support in pediatrics. It is unknown whether newer-generation temporary circulatory support (TCS) devices afford children a meaningful survival advantage over ECMO. OBJECTIVES: This study sought to determine whether bridge-to-heart transplant survival with a TCS device is superior to ECMO after adjusting for patient differences. METHODS: All children ≤21 years of age listed for heart transplant from 2011 to 2015 who received a TCS device or ECMO as a bridge to transplant were identified using Organ Procurement and Transplantation Network data. Children supported with a TCS device were compared with a propensity score (PS)-matched cohort of children supported with ECMO as a bridge to transplant. The primary endpoint was Kaplan-Meier survival to transplant. RESULTS: The number of TCS devices implanted in children increased from ≤3 per year before 2011 to 50 in 2015. Overall, 93 patients implanted with TCS devices were included for analysis (59% left ventricular assist devices, 23% right ventricular assist devices, 18% biventricular assist devices). The most commonly used device was the CentriMag-PediMag system (65%), followed by TandemHeart (18%), Rotaflow (6%), and Impella (5%). Among 164 PS-matched patients, support duration was longer for the TCS cohort (median 19 days vs. 6 days; p < 0.001), and was longest for the CentriMag-PediMag (24 days vs. 6 days; p < 0.001) with 27% supported for >60 days. Compared with the ECMO cohort, the PS-matched TCS cohort had longer survival to transplant (hazard ratio: 0.49; 95% confidence interval: 0.30 to 0.79) and longer overall survival (hazard ratio: 0.61; 95% confidence interval: 0.39 to 0.96), with 90-day mortality before transplant that was modestly reduced (from 45% with ECMO to 39% with TCS). CONCLUSIONS: The use of TCS devices in children as a bridge to transplant has risen rapidly in recent years, led by the growth of magnetically levitated centrifugal flow pumps. Compared with conventional ECMO, TCS durations are longer, and more importantly, patient survival is superior.

Alternative Strategy for Biventricular Assist Device in an Infant With Hypertrophic Cardiomyopathy.

We report an infant with hypertrophic cardiomyopathy who underwent biventricular assist device placement with two 15-mL Berlin Heart EXCOR pediatric ventricular assist devices using an alternative atrial cannulation strategy. The systemic circulation was supported by left atrium (LA) to aorta cannulation. The LA was accessed through the right atrium by extending a 6-mm EXCOR cannula with a Gore-Tex graft connected to an atrial septal defect. The pulmonary circulation was supported with cannulation of the right atrium to pulmonary artery. This alternative cannulation strategy facilitated effective biventricular support and may be applicable to other patients with hypertrophic or restrictive physiology.

Impact of a modified anti-thrombotic guideline on stroke in children supported with a pediatric ventricular assist device.

BACKGROUND: Stroke is the most feared complication associated with the Berlin Heart EXCOR pediatric ventricular assist device (VAD), the most commonly used VAD in children, and affects 1 in 3 children. We sought to determine whether a modified anti-thrombotic guideline, involving more intense platelet inhibition and less reliance on platelet function testing, is associated with a lower incidence of stroke. METHODS: All children supported with the EXCOR at Stanford from 2009 to 2014 were divided into 2 cohorts based on the primary anti-thrombotic guideline used to prevent pump thrombosis: (1) the Edmonton Anti-thrombotic Guideline (EG) cohort, which included children implanted before September 2012 when dual anti-platelet therapy was used with doses titrated to Thromboelastrography/PlateletMapping (TEG/PM); and (2) the Stanford Modified Anti-thrombotic Guideline (SG) cohort, which included children implanted on or after September 2012 when triple anti-platelet therapy was used routinely and where doses were uptitrated to high, weight-based dosing targets, with low-dose steroids administered as needed for inflammation. RESULTS: At baseline, the EG (N = 16) and SG (N = 11) cohorts were similar. The incidence rate of stroke in the SG cohort was 84% lower than in the EG cohort (0.8 vs 4.9 events per 1,000 days of support, p = 0.031), and 86% lower than in the previous Investigational Device Exemption trial (p = 0.006). The bleeding rate was also lower in the SG cohort (p = 0.015). Target doses of aspirin, clopidogrel and dipyridamole were higher (all p < 0.003), with less dosing variability in the SG cohort than in the EG cohort. There was no difference in adenosine diphosphate inhibition by TEG/PM, but arachidonic acid inhibition was higher in the SG cohort (median 75% vs 39%, p = 0.008). CONCLUSIONS: Stroke was significantly less common in pediatric patients supported with the Berlin Heart EXCOR VAD using a triple anti-platelet regimen uptitrated to high, weight-based dosing targets as compared with the dual anti-platelet regimen titrated to PM, and without a higher risk of bleeding. Larger studies are needed to confirm these findings.

Major Aortopulmonary Collateral Arteries With Anatomy Other Than Pulmonary Atresia/Ventricular Septal Defect.

BACKGROUND: Major aortopulmonary collateral arteries (MAPCAs) are frequently found in association with pulmonary atresia with ventricular septal defect (PA/VSD). However, some patients with MAPCAs do not have PA/VSD but have a variety of other "atypical" anatomic diagnoses. METHODS: This was a retrospective review of patients with MAPCAs and atypical anatomy. The 50 patients with MAPCAs could be divided into two subgroups: (1) single ventricle anatomy (n = 33) and (2) two ventricle anatomy (n = 17). RESULTS: The 33 patients with MAPCAs and single ventricle included 15 with unbalanced complete atrioventricular canal (CAVC), 6 with pulmonary atresia-intact ventricular septum, and 12 with other forms of single ventricle. The initial cardiac operation included unifocalization/shunt in 24 patients and creation of aortopulmonary window or central shunt in 9 patients. There were seven operative and eight late deaths. Sixteen patients have had a bidirectional Glenn procedure and 6 had a Fontan procedure. The 17 patients with MAPCAs and two ventricles included 5 with CAVC, 4 with corrected transposition, 3 with double outlet right ventricle, 3 with scimitar syndrome, and 2 with complex D-transposition. The initial cardiac operation included single-stage complete repair in 5 patients, unifocalization/shunt in 10 patients, and aortopulmonary window in 2 patients. There were two operative and two late deaths. Thirteen patients have achieved complete repair status. CONCLUSIONS: The data demonstrate the wide diversity of anatomy seen in patients with MAPCAs when evaluating diagnoses other than PA/VSD. Two-thirds of the patients had single ventricle and was associated with a relatively high mortality.

Functional status of United States children supported with a left ventricular assist device at heart transplantation.

BACKGROUND: As survival with pediatric left ventricular assist devices (LVADs) has improved, decisions regarding the optimal support strategy may depend more on quality of life and functional status (FS) rather than mortality alone. Limited data are available regarding the FS of children supported with LVADs. We sought to compare the FS of children supported with LVADs vs vasoactive infusions to inform decision making around support strategies. METHODS: Organ Procurement and Transplant Network data were used to identify all United States children aged between 1 and 21 years at heart transplant (HT) between 2006 and 2015 for dilated cardiomyopathy and supported with an LVAD or vasoactive infusions alone at HT. FS was measured using the 10-point Karnofsky and Lansky scale. RESULTS: Of 701 children who met the inclusion criteria, 430 (61%) were supported with vasoactive infusions, and 271 (39%) were supported with an LVAD at HT. Children in the LVAD group had higher median FS scores at HT than children in the vasoactive infusion group (6 vs 5, p < 0.001) but lower FS scores at listing (4 vs 6, p < 0.001). The effect persisted regardless of patient location at HT (home, hospital, intensive care) or device type. Discharge by HT occurred in 46% of children in the LVAD group compared with 26% of children in the vasoactive infusion cohort (p = 0.001). Stroke was reported at HT in 3% of children in the LVAD cohort and in 1% in the vasoactive infusion cohort (p = 0.04). CONCLUSIONS: Among children with dilated cardiomyopathy undergoing HT, children supported with LVADs at HT have higher FS than children supported with vasoactive infusions at HT, regardless of device type or hospitalization status. Children supported with LVADs at HT were more likely to be discharged from the hospital but had a higher prevalence of stroke at HT.

Superior performance of continuous over pulsatile flow ventricular assist devices in the single ventricle circulation: A computational study.

This study compares the physiological responses of systemic-to-pulmonary shunted single ventricle patients to pulsatile and continuous flow ventricular assist devices (VADs). Performance differences between pulsatile and continuous flow VADs have been clinically observed, but the underlying mechanism remains poorly understood. Six systemic-to-pulmonary shunted single ventricle patients (mean BSA=0.30m2) were computationally simulated using a lumped-parameter network tuned to match patient specific clinical data. A first set of simulations compared current clinical implementation of VADs in single ventricle patients. A second set modified pulsatile flow VAD settings with the goal to optimize cardiac output (CO). For all patients, the best-case continuous flow VAD CO was at least 0.99L/min greater than the optimized pulsatile flow VAD CO (p=0.001). The 25 and 50mL pulsatile flow VADs exhibited incomplete filling at higher heart rates that reduced CO as much as 9.7% and 37.3% below expectations respectively. Optimization of pulsatile flow VAD settings did not achieve statistically significant (p<0.05) improvement to CO. Results corroborate clinical experience that continuous flow VADs produce higher CO and superior ventricular unloading in single ventricle patients. Impaired filling leads to performance degradation of pulsatile flow VADs in the single ventricle circulation.

Outcomes of pediatric patients supported with continuous-flow ventricular assist devices: A report from the Pediatric Interagency Registry for Mechanical Circulatory Support (PediMACS).

BACKGROUND: Continuous-flow (CF) ventricular assist devices (VADs) have largely replaced pulsatile-flow VADs in adult patients. However, there are few data on CF VADs among pediatric patients. In this study we aimed to describe the overall use, patients' characteristics and outcomes of CF VADs in this population. METHODS: The Pediatric Interagency Registry for Mechanical Circulatory Support (PediMACS) is a national registry for U.S. Food and Drug Adminstration (FDA)-approved VADs in patients <19 years of age. Patients undergoing placement of durable CF VADs between September 2012 and June 2015 were included and outcomes were compared with those of adults from the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS). RESULTS: CF VADs were implanted in 109 patients at 35 hospitals. The median age at implantation was 15 years (2.8 to 18.9 years) and median weight was 62 kg (range 16 to 141 kg). The underlying disease was cardiomyopathy in 89 (82%) patients. The INTERMACS level at time of implant was Level 1 in 20 (19%), Level 2 in 64 (61%) and Levels 3 to 7 in 21 (20%) patients. Most were implanted as LVADs (n = 102, 94%). Median duration of support was 2.3 months (range <1 day to 28 months). Serious adverse event rates were low, including neurologic dysfunction (early event rate 4.1 per 100 patient-months with 2 late events). Competing outcomes analysis at 6 months post-implant indicated 61% transplanted, 31% alive with device in place and 8% death before transplant. These outcomes compared favorably with the 3,894 adults supported with CF VADs as a bridge to transplant. CONCLUSIONS: CF VADs are commonly utilized in older children and adolescents, with excellent survival rates. Further study is needed to understand impact of patient and device characteristics on outcomes in pediatric patients.

HeartWare HVAD for Biventricular Support in Children and Adolescents: The Stanford Experience.

Despite increasing use of mechanical circulatory support in children, experience with biventricular device implantation remains limited. We describe our experience using the HeartWare HVAD to provide biventricular support to three patients and compare these patients with five patients supported with HeartWare left ventricular assist device (LVAD). At the end of the study period, all three biventricular assist device (BiVAD) patients had been transplanted and were alive. LVAD patients were out of bed and ambulating a median of 10.5 days postimplantation. The BiVAD patients were out of bed a median of 31 days postimplantation. Pediatric patients with both left ventricular and biventricular heart failure can be successfully bridged to transplantation with the HeartWare HVAD. Rapid improvement in functional status following HVAD implantation for isolated left ventricular support is seen. Patients supported with BiVAD also demonstrate functional recovery, albeit more modestly. In the absence of infection, systemic inflammatory response raises concern for inadequate support.

Outpatient Outcomes of Pediatric Patients with Left Ventricular Assist Devices.

Outpatient experience of children supported with continuous-flow ventricular assist devices (CF-VAD) is limited. We reviewed our experience with children discharged with CF-VAD support. All pediatric patients <18 years old with CF-VADs implanted at our institution were included. Discharge criteria included a stable medication regimen, completion of a VAD education program and standardized rehabilitation plan, and presence of a caregiver. Hospital readmissions (excluding scheduled admissions) were reviewed. Adverse events were defined by Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) criteria. Of 17 patients with CF-VADs, 8 (47%) were discharged from the hospital (1 HeartWare ventricular assist device (Heartware Inc., Framingham, MA), 7 HeartMate II (Thoratec Corp, Pleasanton, CA)). Median age was 15.3 (range 9.6-17.1) years and weight was 50.6 (33.6-141) kg. Device strategies were destination therapy (DT; n = 4) and bridge to transplant (n = 4). Patients spent a median 49 (26-107) days hospitalized postimplant and had 2 (1-5) hospital readmissions. Total support duration was 3,154 patient-days, with 2,413 as outpatient. Most frequent adverse events were device malfunction and arrhythmias. There was one death because of pump thrombosis and no bleeding or stroke events. Overall adverse event rate was 15.22 per 100 patient-months. Early experience suggests that children with CF-VADs can be safely discharged. Device malfunction and arrhythmia were the most common adverse events but were recognized quickly with structured outpatient surveillance.

Anatomic Factors Associated With Truncal Valve Insufficiency and the Need for Truncal Valve Repair.

PURPOSE: Truncus arteriosus is a complex and heterogeneous form of congenital heart defect. Many of the risk factors from several decades ago, including late repair and interrupted aortic arch, have been mitigated through better understanding of the entity and improved surgical techniques. However, truncal valve dysfunction remains an important cause of morbidity and mortality. The purpose of this study was to evaluate the anatomic factors associated with truncal valve dysfunction and the need for truncal valve surgery. METHODS: This was a retrospective review of 72 infants who underwent repair of truncus arteriosus at our institution. The median age at surgery was nine days, and the median weight was 3.1 kg. Preoperative assessment of truncal valve insufficiency by echocardiography revealed no or trace insufficiency in 30, mild in 25, moderate in 10, and severe in 7. The need for truncal valve surgery was dictated by the severity of truncal valve insufficiency. RESULTS: Sixteen (22%) of the 72 patients undergoing truncus arteriosus repair had concomitant truncal valve surgery. Anatomic factors associated with the need for truncal valve surgery included an abnormal number of truncal valve cusps (P < .005), presence of valve dysplasia (P < .005), and the presence of an anomalous coronary artery pattern (P < .005). Fifteen (94%) of the sixteen patients who underwent concomitant surgery had two or all three of these anatomic factors (sensitivity = 94%, specificity = 85%). CONCLUSION: This study demonstrates that the presence of specific anatomic factors was closely associated with the presence of truncal valve insufficiency and the need for concomitant truncal valve surgery. Preoperative evaluation of these anatomic factors may provide a useful tool in determining who should undergo concomitant truncal valve surgery.

Ventricular assist devices in a contemporary pediatric cohort: Morbidity, functional recovery, and survival.

BACKGROUND: Limited availability of donor organs has led to the use of ventricular assist devices (VADs) to treat heart failure in pediatric patients, primarily as bridge to transplantation. How effective VAD therapy is in promoting functional recovery in children is currently not known. METHODS: We report morbidity and mortality as defined by the Interagency Registry for Mechanically Assisted Circulatory Support Modified for Pediatrics (PediMACS) and the use of the Treatment Intensity Score to assess functional status for 50 VAD patients supported at a single pediatric program from 2004 to 2013. RESULTS: In this cohort, 30-day survival on VAD was 98%, and 180-day survival was 83%. Stroke occurred in 11 patients (22%), with 8 (16%) resulting in persistent neurologic deficit or death. The adverse event rate was 2-fold to 3-fold higher in the first 7 days of support compared with the subsequent support period. Functional status, as measured by the Treatment Intensity Score, improved with duration of support. Successful bridge to transplantation was associated with fewer adverse events during support and greater improvement in the Treatment Intensity Score during the period of support. CONCLUSIONS: Overall survival in this cohort is excellent. The risk of serious adverse events decreases over the first month of support. However, a clinically significant risk of morbidity and mortality persists for the duration of pediatric VAD support. Measures of functional status improve with duration of support and are associated with survival to transplantation.