Left Ventricular Outflow Tract Obstruction in Congenital Heart Disease: The Role of Cardiovascular Computed Tomography in Surgical Decision Making.

Patients with many forms of congenital heart disease (CHD) and hypertrophic cardiomyopathy undergo surgical intervention to relieve left ventricular outflow tract obstruction (LVOTO). Cardiovascular Computed Tomography (CCT) defines the complex pathway from the ventricle to the outflow tract and can be visualized in 2D, 3D, and 4D (3D in motion) to help define the mechanism and physiologic significance of obstruction. Advanced cardiac visualization may aid in surgical planning to relieve obstruction in the left ventricular outflow tract, aortic or neo-aortic valve and the supravalvular space. CCT scanner technology has advanced to achieve submillimeter, isotropic spatial resolution, temporal resolution as low as 66 msec allowing high-resolution imaging even at the fast heart rates and small cardiac structures of pediatric patients ECG gating techniques allow radiation exposure to be targeted to a minimal portion of the cardiac cycle for anatomic imaging, and pulse modulation allows cine imaging with a fraction of radiation given during most of the cardiac cycle, thus reducing radiation dose. Scanning is performed in a single heartbeat or breath hold, minimizing the need for anesthesia or sedation, for which CHD patents are highest risk for an adverse event. Examples of visualization of complex left ventricular outflow tract obstruction in the subaortic, valvar and supravalvular space will be highlighted, illustrating the novel applications of CCT in this patient subset.

Heart Transplant and Donors After Circulatory Death: A Clinical-Preclinical Systematic Review.

INTRODUCTION: Heart transplantation is the treatment of choice for end-stage heart failure. There is a mismatch between the number of donor hearts available and the number of patients awaiting transplantation. Expanding the donor pool is critically important. The use of hearts donated following circulatory death is one approach to increasing the number of available donor hearts. MATERIALS AND METHODS: A systematic review was performed according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines utilizing Pubmed/MEDLINE and Embase. Articles including adult human studies and preclinical animal studies of heart transplantation following donation after circulatory death were included. Studies of pediatric populations or including organs other than heart were excluded. RESULTS: Clinical experience and preclinical studies are reviewed. Clinical experience with direct procurement, normothermic regional perfusion, and machine perfusion are included. Preclinical studies addressing organ function assessment and enhancement of performance of marginal organs through preischemic, procurement, preservation, and reperfusion maneuvers are included. Articles addressing the ethical considerations of thoracic transplantation following circulatory death are also reviewed. CONCLUSIONS: Heart transplantation utilizing organs procured following circulatory death is a promising method to increase the donor pool and offer life-saving transplantation to patients on the waitlist living with end-stage heart failure. There is robust ongoing preclinical and clinical research to optimize this technique and improve organ yield. There are also ongoing ethical considerations that must be addressed by consensus before wide adoption of this approach.

Fontan-associated liver disease after heart transplant.

BACKGROUND: Fontan associated liver disease (FALD) potentially impacts Fontan patients undergoing heart transplant. This multi-center study sought to identify pre-transplant risk factors and characterize any post-transplant liver recovery in those patients undergoing heart-alone transplant. METHODS: Review of Fontan patients at 12 pediatric institutions who underwent heart transplant between 2001-2019. Radiologists reviewed pre and post-transplant liver imaging for fibrosis. Laboratory, pathology and endoscopy studies were reviewed. RESULTS: 156 patients underwent transplant due to decreased ventricular function (49%), protein losing enteropathy (31%) or plastic bronchitis (10%); median age at transplant was 13.6 years (interquartile range IQR 7.8, 17.2) with a median of 9.3 years (IQR 3.2, 13.4) between the Fontan operation and transplant. Few patients had pre-transplant endoscopy (18%), and liver biopsy (19%). There were 31 deaths (20%). The median time from transplant to death was 0.5 years (95% Confidence Interval CI 0.0, 3.6). The five-year survival was 73% (95% CI 64%, 83%). Deaths were related to cardiac causes in 68% (21/31) and infection in 6 (19%). A pre-transplant elevation in bilirubin was a predictor of death. Higher platelet levels were protective. Immediate post-transplant elevations in creatinine, AST, ALT, and INR were predictive of death. Advanced liver fibrosis identified on ultrasound, computed tomography, or magnetic resonance imaging was not predictive of death. Liver imaging suggested some improvement in liver congestion post-transplant. CONCLUSIONS: Elevated bilirubin, but not fibrosis on liver imaging, was associated with post-heart transplant mortality in Fontan patients in this multicenter retrospective study. Additionally, heart transplant may alter the progression of FALD.

Impact of tacrolimus variability on pediatric heart transplant outcomes.

BACKGROUND: Tacrolimus is a narrow therapeutic index drug, requiring consistent levels to maximize transplant success while reducing adverse effects. Elevated tacrolimus level variability (ETLV) is associated with poor outcomes in both pediatric and adult solid organ transplant recipients. We sought to describe the prevalence of ETLV and identify associations with patient-specific factors and poor outcomes. METHODS: Tacrolimus levels were evaluated from 118 patients at our single center. As a marker of variability, standard deviations (SD) were calculated for each patient from their entire tacrolimus level data set (global SD), and 1-2 years and 1-5 years post-HT (prediction window SDs). SD ≥3 denoted ETLV. RESULTS: There was large variability in tacrolimus levels (median global SD 3.1; IQR 2.3, 4; SD ≥3, n = 64, 54%). Patients with elevated SD (≥3) vs lower SD (<3) were more likely to have poor outcomes including rejection (73% vs 46%), cardiac allograft vasculopathy (CAV, 22% vs 9%), and death (20% vs 6%). The prediction window analysis noted ETLV was associated with a 40% greater risk of CAV, re-HT, or death (p = .024) and increasing age at transplantation was associated with a 12% increase in the risk of rejection (p = <.001) and a 19% increase in the risk of a composite event (p = .021). CONCLUSION: ETLV is prevalent in the pediatric HT population with increased frequency of poor outcomes in those with SD ≥3. ETLV is an easily accessible marker with which to risk-stratify patients.

Thrombotic microangiopathy following heart transplant in pediatric Danon disease.

This case describes an uncommon acute complication of diffuse thrombotic angiopathy and associated aHUS/TTP in an 11-year-old girl with Danon disease who underwent orthotopic heart transplant. Shortly after transplant, despite an uncomplicated operative course, the patient developed severe kidney injury and progressive altered mental status, culminating in cerebral edema, brain herniation, and death. She had received a single dose of tacrolimus (FK506) and a single dose of antithymocyte globulin. Sources of progressive somnolence, including oversedation from impaired renal clearance of opiates, and severe myopathy as has been previously described in Danon disease, were ruled out, and the patient continued to decline. Initial brain CT scan early after transplant showed no signs of cerebral edema, but repeat CT indicated severe cerebral edema. Based on autopsy, diffuse thrombotic angiopathy, with signs of hemolytic anemia with schistocytes, was likely responsible for her deterioration in the broader condition of aHUS/TTP.

Differences in clinical outcomes and cost between complex and simple arterial switches.

BACKGROUND: This study evaluates the morbidity, mortality, and cost differences between patients who underwent either a simple or a complex arterial switch operation. METHODS: A retrospective study of patients undergoing an arterial switch operation at a single institution was performed. Simple cases were defined as patients with d-transposition of the great arteries with usual coronary anatomy or circumflex artery originating from the right with either intact ventricular septum or ventricular septal defect. Complex cases included all other forms of coronary anatomy, aortic coarctation or arch hypoplasia, and Taussig-Bing anomalies. Costs were acquired using an institutional activity-based accounting system. RESULTS: A total of 98 patients were identified, 68 patients in the simple group and 30 in the complex group. The mortality rate was 2% for the simple and 7% for the complex group, p=0.23. Major morbidities including cardiac arrest, extracorporeal membrane oxygenation, a major coronary event, surgical or catheter-based re-intervention, stroke, or permanent pacemaker placement, non-cardiac surgical procedures, mediastinitis, and sepsis did not differ between the simple and complex groups (16 versus 27%, p=0.16). The complex group had increased bleeding requiring re-exploration (0 versus 10%, p=0.04). Hospital and ICU length of stay did not differ. Complex patients had higher overall hospital costs (simple $80,749 versus complex $97,387, p=0.01) and higher postoperative costs (simple $60,192 versus complex $70,132, p=0.02). The operating room and supplies accounted for the majority of the cost difference. CONCLUSION: Complex arterial switches can be safely performed with low rates of morbidity and mortality but at an increased cost.

Blau syndrome-associated Nod2 mutation alters expression of full-length NOD2 and limits responses to muramyl dipeptide in knock-in mice.

The biochemical mechanism by which mutations in nucleotide-binding oligomerization domain containing 2 (NOD2) cause Blau syndrome is unknown. Several studies have examined the effect of mutations associated with Blau syndrome in vitro, but none has looked at the implication of the mutations in vivo. To test the hypothesis that mutated NOD2 causes alterations in signaling pathways downstream of NOD2, we created a Nod2 knock-in mouse carrying the most common mutation seen in Blau syndrome, R314Q (corresponding to R334Q in humans). The endogenous regulatory elements of mouse Nod2 were unaltered. R314Q mice showed reduced cytokine production in response to i.p. and intravitreal muramyl dipeptide (MDP). Macrophages from R314Q mice showed reduced NF-κB and IL-6 responses, blunted phosphorylation of MAPKs, and deficient ubiquitination of receptor-interacting protein 2 in response to MDP. R314Q mice expressed a truncated 80-kDa form of NOD2 that was most likely generated by a posttranslational event because there was no evidence for a stop codon or alternative splicing event. Human macrophages from two patients with Blau syndrome also showed a reduction of both cytokine production and phosphorylation of p38 in response to MDP, indicating that both R314Q mice and cells from patients with Blau syndrome show reduced responses to MDP. These data indicate that the R314Q mutation when studied with the Nod2 endogenous regulatory elements left intact is associated with marked structural and biochemical changes that are significantly different from those observed from studies of the mutation using overexpression, transient transfection systems.

Interdigitating Technique for Repair of Aortic Arch Obstruction to Reduce Reintervention Rates.

BACKGROUND: The incidence of reintervention for aortic arch obstruction is 5% to 14% after coarctation or hypoplastic aortic arch repair and 25% after the Norwood procedure. Institutional practice review indicated higher than reported reintervention rates. Our aim was to assess the impact of an interdigitating reconstruction technique on reintervention rates for recurrent aortic arch obstruction. METHODS: Children (<18 years) were included if they had undergone aortic arch reconstruction by sternotomy or the Norwood procedure. Three surgeons participated in the intervention with staggered rollout dates between June 2017 and January 2019, with the study ending December 2020 and review for reinterventions ending February 2022. Preintervention cohorts represented patients who underwent aortic arch reconstructions with patch augmentation, and postintervention cohorts represented patients who underwent an interdigitating reconstruction technique. Reinterventions by cardiac catheterization or operation were measured within 1 year of initial operation. Wilcoxon rank sum and χ2 tests were used to compare preintervention and postintervention cohorts. RESULTS: Overall, 237 patients were included for participation in this study, with 84 patients in the preintervention cohort and 153 in the postintervention cohort. Patients undergoing the Norwood procedure represented 30% (n = 25) of the retrospective cohort and 35% (n = 53) of the intervention cohort. Overall reinterventions were significantly decreased after the study intervention from 31% (n = 26/84) to 13% (n = 20/153; P < .001). Reintervention rates were decreased for each intervention cohort: aortic arch hypoplasia (24% [n = 14/59] vs 10% [n = 10/100]; P = .019) and Norwood procedure (48% [n = 12/25] vs 19% [n = 10/53]; P = .008). CONCLUSIONS: The interdigitating reconstruction technique for obstructive aortic arch lesions was successfully implemented and is associated with a decrease in reinterventions.

Impact of Atrioventricular Valve Intervention at Each Stage of Single Ventricle Palliation.

Background: Significant atrioventricular valve dysfunction can be associated with mortality or need for transplant in functionally univentricular heart patients undergoing staged palliation. The purposes of this study are to characterize the impact of concomitant atrioventricular valve intervention on outcomes at each stage of single ventricle palliation and to identify risk factors associated with poor outcomes in these patients. Methods: The Society of Thoracic Surgeons Congenital Heart Surgery Database was queried for functionally univentricular heart patients undergoing single ventricle palliation from 2013 through 2022. Separate analyses were performed on cohorts corresponding to each stage of palliation (1: initial palliation; 2: superior cavopulmonary anastomosis; 3: Fontan procedure). Bivariate analysis of demographics, diagnoses, comorbidities, preoperative risk factors, operative characteristics, and outcomes with and without concomitant atrioventricular valve intervention was performed. Multiple logistic regression was used to identify predictors associated with operative mortality or major morbidity. Results: Concomitant atrioventricular valve intervention was associated with an increased risk of operative mortality or major morbidity for each cohort (cohort 1: 62% vs 46%, P < .001; cohort 2: 37% vs 19%, P < .001; cohort 3: 22% vs 14%, P < .001). Black race in cohort 1 (odds ratio [OR] 3.151, 95% CI 1.181-9.649, P = .03) and preterm birth in cohort 2 (OR 1.776, 95% CI 1.049-3.005, P = .032) were notable predictors of worse morbidity or mortality. Conclusions: Concomitant atrioventricular valve intervention is a risk factor for operative mortality or major morbidity at each stage of single ventricle palliation. Several risk factors are associated with these outcomes and may be useful in guiding decision-making.

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.

Genome Sequencing is Critical for Forecasting Outcomes following Congenital Cardiac Surgery.

While genome sequencing has transformed medicine by elucidating the genetic underpinnings of both rare and common complex disorders, its utility to predict clinical outcomes remains understudied. Here, we used artificial intelligence (AI) technologies to explore the predictive value of genome sequencing in forecasting clinical outcomes following surgery for congenital heart defects (CHD). We report results for a cohort of 2,253 CHD patients from the Pediatric Cardiac Genomics Consortium with a broad range of complex heart defects, pre- and post-operative clinical variables and exome sequencing. Damaging genotypes in chromatin-modifying and cilia-related genes were associated with an elevated risk of adverse post-operative outcomes, including mortality, cardiac arrest and prolonged mechanical ventilation. The impact of damaging genotypes was further amplified in the context of specific CHD phenotypes, surgical complexity and extra-cardiac anomalies. The absence of a damaging genotype in chromatin-modifying and cilia-related genes was also informative, reducing the risk for adverse postoperative outcomes. Thus, genome sequencing enriches the ability to forecast outcomes following congenital cardiac surgery.

Impact of a Surgical Wound Infection Prevention Bundle in Pediatric Cardiothoracic Surgery.

BACKGROUND: The aim of this project was to decrease the incidence of surgical wound infection (SWI) to <1.5% in our pediatric cardiothoracic surgery patients using a prevention bundle and quality improvement process. METHODS: An SWI prevention bundle addressing preoperative, intraoperative, and postoperative risks was implemented. The primary outcome was SWI based on Society of Thoracic Surgeons criteria (superficial, deep, or mediastinitis). Novel aspects of the bundle included standardization of surgical closure and wound coverage for 14 days with a negative pressure dressing or a silicone dressing. Data were collected from January 2017 to November 2021; bundle intervention began in December 2019. SWIs were tracked using a g-chart. Preintervention and postintervention cohorts were compared by standard descriptive statistics. There were no changes in SWI tracking methods during the study. RESULTS: During the study, 1159 individuals underwent 1768 surgical interventions. Preintervention (n = 931) and postintervention (n = 837) groups were clinically similar, with fewer neonatal surgeries in the postintervention group. SWI decreased in all patients (preintervention period: 1 SWI per 22 surgeries; postintervention period: 1 SWI per 62.6 surgeries) and in neonates (preintervention period: 1 SWI per 12 surgeries; postintervention period: 1 SWI per 26.7 surgeries). Special cause variation was achieved in the entire cohort by March 2021 and in neonates by April 2021. Decreases in SWI occurred in superficial and deep wounds but not in mediastinitis. Annual rate of total SWIs decreased from 2.83% in 2019 to 1.15% in 2021. Intensive care unit and hospital length of stay did not change. CONCLUSIONS: We demonstrated a reduction in SWI rates after implementing an SWI prevention bundle including standardized surgical closure and prolonged wound protection.

Transcatheter and Surgical Aortic Valve Implantation in Children, Adolescents, and Young Adults With Congenital Heart Disease.

Transcatheter aortic valve implantation (TAVI) is common in adults but rare in children and adolescents. Since 2014, our institution has incorporated a transcatheter approach as an option for aortic valve replacement in this population. The purpose of this study was to compare short-term outcomes of TAVI with surgical aortic valve replacement (SAVR). This single-center, retrospective study included patients aged 10 to 21 years who had a native SAVR or TAVI between January 2010 to April 2020. Comparative analysis of baseline characteristics and a composite outcome (stroke within 6 months, readmission within 30 days, death) between SAVR and TAVI were made using chi-square test or Wilcoxon rank sum test, as appropriate. Of the 77 patients who underwent native aortic valve implantation during the study period (60 SAVR, 17 TAVI), 46 were aged 10 to 21 years (30 SAVR, 16 TAVI). Median follow-up was 3.8 years (interquartile range 1.5 to 4.9) for the SAVR group and 1.5 years (interquartile range 1.1 to 1.2) for the TAVI group. There was no difference in the composite outcome between groups. Patients in the SAVR group were more likely to have undergone concomitant surgical intervention and have longer intensive care unit and hospital stays. In conclusion, our study suggests similar short-term outcomes between SAVR and TAVI in children and young adults aged 10 to 21 years. Longer-term studies are essential to understand the utility of TAVI and to better consider the option of a transcatheter approach as an alternative to SAVR in the pediatric population.

Time in Therapeutic Range for Bivalirudin Among Pediatric Ventricular Assist Device Recipients.

Given the adverse event rates involving bleeding and thrombosis among children on ventricular assist devices (VADs), anticoagulant management has become a focal point for quality improvement and innovation. There may be advantages to using direct thrombin inhibitors, such as bivalirudin, though this has not been fully explored. As the percent time in therapeutic range (%TTR) for anticoagulants is classically associated with improved clinical outcomes, we evaluated the %TTR for bivalirudin among pediatric VAD recipients. Using a modification of the Rosendaal method, %TTR was calculated using activated partial thromboplastin time measurements for 11 VAD recipients in the early postoperative period (postoperative days 0-14) and for the duration of VAD support. In the initial 2 weeks after VAD implant, mean %TTR was 68.7 (±13.0). During the entire support course, the mean %TTR improved to 79.6 (±11.0). There was an era effect with improving %TTR in the latter half of the study period. We report very good %TTR for bivalirudin both in the first 2 weeks post implant and this improved over the duration of support. Because %TTR reflects the degree of safety and efficacy in chronic anticoagulation, this relatively high %TTR among a diverse, often critically ill cohort suggests that bivalirudin may be a promising agent. Although this study was underpowered to comprehensively evaluate adverse events on bivalirudin, this represents an important next step for larger scale study.

Berlin Heart EXCOR and ACTION post-approval surveillance study report.

BACKGROUND: The Berlin Heart EXCOR Pediatric (EXCOR) ventricular assist device (VAD) was introduced in North America nearly 2 decades ago. The EXCOR was approved under Humanitarian Device Exemption status in 2011 and received post-market approval (PMA) in 2017 from Food and Drug Administration. Since the initial approval, the field of pediatric mechanical circulatory support has changed, specifically with regard to available devices, anticoagulation strategies, and the types of patients supported. This report summarizes the outcomes of patients supported with EXCOR from the Advanced Cardiac Therapies Improving Outcomes Network (ACTION) registry. These data were part of the PMA surveillance study (PSS) required by the Food and Drug Administration. METHODS: ACTION is a learning collaborative of over 40 pediatric heart failure programs worldwide, which collects data for all VAD implantations as one of its initiatives. All patients in North America with EXCOR implants reported to ACTION from 2018 to 2020 (n = 72) who had met an outcome were included in the EXCOR PSS group. This was compared with a historical, previously reported Berlin Heart EXCOR study group (Berlin Heart study [BHS] group, n = 320, 2007‒2014). RESULTS: Patients in the PSS group were younger, were smaller in weight/body surface area, were more likely to have congenital heart disease, and were less likely to receive a bi-VAD than those in the BHS group. Patients in the PSS group were less likely to be in Interagency Registry for Mechanically Assisted Circulatory Support Profile 1 and were supported for a longer duration. The primary anticoagulation therapy for 92% of patients in the PSS group was bivalirudin. Success, defined as being transplanted, being weaned for recovery, or being alive on a device at 180 days after implantation, was 86% in the PSS group compared with 76% in the BHS group. Incidence of stroke was reduced by 44% and the frequency of pump exchange by 40% in the PSS group compared with those in the BHS group. Similarly, all other adverse events, including major bleeding, were reduced in the PSS group. CONCLUSIONS: The PSS data, collected through ACTION, highlight the improvement in outcomes for patients supported with EXCOR compared with the outcomes in a historical cohort. These findings may be the result of changes in patient care practices over time and collaborative learning.

Utilization and Outcomes of Children Treated with Direct Thrombin Inhibitors on Paracorporeal Ventricular Assist Device Support.

Thrombotic and bleeding complications have historically been major causes of morbidity and mortality in pediatric ventricular assist device (VAD) support. Standard anticoagulation with unfractionated heparin is fraught with problems related to its heterogeneous biochemical composition and unpredictable pharmacokinetics. We sought to describe the utilization and outcomes in children with paracorporeal VAD support who are treated with direct thrombin inhibitors (DTIs) antithrombosis therapy. Retrospective multicenter review of all pediatric patients (aged <19 years) treated with a DTI (bivalirudin or argatroban) on paracorporeal VAD support, examining bleeding and thrombotic adverse events. From May 2012 to 2018, 43 children (21 females) at 10 centers in North America, median age 9.5 months (0.1-215 months) weighing 8.6 kg (2.8-150 kg), were implanted with paracorporeal VADs and treated with a DTI. Diagnoses included cardiomyopathy 40% (n = 17), congenital heart disease 37% (n = 16; single ventricle n = 5), graft vasculopathy 9% (n = 4), and other 14% (n = 6). First device implanted included Berlin Heart EXCOR 49% (n = 21), paracorporeal continuous flow device 44% (n = 19), and combination of devices in 7% (n = 3). Adverse events on DTI therapy included; major bleeding in 16% (n = 7) (2.6 events per 1,000 patient days of support on DTI), and stroke 12% (n = 5) (1.7 events per 1,000 patient days of support on DTI). Overall survival to transplantation (n = 30) or explantation (n = 8) was 88%. This is the largest multicenter experience of DTI use for anticoagulation therapy in pediatric VAD support. Outcomes are encouraging with lower major bleeding and stroke event rate than that reported in literature using other anticoagulation agents in pediatric VAD support.

Outcomes of children supported with an intracorporeal continuous-flow left ventricular assist system.

BACKGROUND: Since 2012, there has been growing use of the HeartWare (Medtronic, Mounds View, MN) intracorporeal continuous flow (CF) ventricular assist device (VAD) in children, despite it not being labeled for use in pediatric patients. We sought to describe the use and outcomes of children with HeartWare VADs. METHODS: We identified all patients aged < 19 years and young adults aged 19 to 30 years supported with HeartWare who were entered into the pediatric portion (Pedimacs) of the Interagency Registry for Mechanically Assisted Circulatory Support (Intermacs) and the Intermacs registries, respectively, between September 2012 and June 2017. Adverse events and outcomes were analyzed and compared. RESULTS: We identified 192 children and 247 young adult HeartWare patients. Baseline characteristics of children differed from young adults, with lower median weight of 51.5 kg (range, 13.1-162) vs 75.8 kg (range, 29.8-191; p ≤ 0.0001) and body surface area of 1.5 m2 (range, 0.6-2.9 m2) vs 1.9 m2 (range, 1.1-3.2 m2; p ≤ 0.0001) . At the time of implant, 12 children weighed < 20 kg, and 58.3% of these children had congenital heart disease compared with 11.7% in children who weighed ≥ 20 kg and 6.1% in young adults (p ≤ 0.0001). Median duration of support was 2.8 months (IQR, 1.3-6.0 months) in children and 9.7 months (IQR 4.0-19.2 months) in young adults (p ≤ 0.0001). Serious adverse events in children and young adults included infection in 27% and 44% of patients, respectively (p=0.0002), major bleeding in 23% and 23%, respectively (p = 0.9), device malfunction/pump thrombosis in 11% and 19.0%, respectively (p = 0.04), and stroke in 10% and 12%, respectively (p = 0.5). Of the children who weighed < 20 kg at time of implant, 0% had major bleeding, 16.7% had infections, and 8.3% had stroke. Overall survival was not statistically different between children and young adults, and there was no increased mortality in children who weighed < 20 kg. Rate of discharge on HeartWare was 80% in young adults vs 48% in children who weighed ≥ 20 kg and only 33% in children who weighed < 20 kg. CONCLUSIONS: Survival in children supported with HeartWare is encouraging and comparable to young adults; however, adverse events are not uncommon in children. Ongoing evaluation of the HeartWare use in children is necessary to further decrease the rate of adverse events and understand obstacles to discharge.

Single-Ventricle Palliation in a 4-Year-Old With Ehlers-Danlos Syndrome.

We report the case of a 4-year-old boy with Ehlers-Danlos syndrome undergoing single-ventricle palliation for an unbalanced atrioventricular canal defect. No reports of single-ventricle palliation in the setting of connective tissue disorders exist in the current literature. Unique findings on the patient's preoperative imaging included a disproportionately large neoaortic root and a regurgitant atrioventricular valve, which may foretell the need for future intervention.

Pulmonary Valve Replacement: A Single-Institution Comparison of Surgical and Transcatheter Valves.

BACKGROUND: Transcatheter pulmonary valve replacement (TPVR) is increasingly utilized to address residual or recurrent right ventricular outflow tract pathology in congenital heart disease patients. We aimed to evaluate clinical outcomes and resource utilization comparing TPVR to surgical pulmonary valve replacement (SPVR) for this patient population. METHODS: From January 2010 until December 2015, 224 patients underwent pulmonary valve replacement (SPVR = 100 and TPVR = 124). These groups were assessed and compared for survival, reoperation, reintervention (surgical or catheter based), hospital costs, and hemodynamic performance. RESULTS: There were no mortalities in either group. Despite SPVR patients being significantly younger (12 ± 7 years of age versus 19 ± 13 years of age; p < 0.001) and smaller (body surface area 1.2 ± 0.5 m2 versus 1.4 ± 0.5 m2; p < 0.001), they had similar median valve size implanted (23 mm [interquartile range, 21 to 27 mm) versus 22 mm [interquartile range, 20 to 22 mm]). There was no difference in the adjusted peak gradient (SPVR 24.1 ± 15.1 mm Hg versus TPVR 20.7 ± 11.4 mm Hg; p = 017) at last follow-up. Cumulative freedom from reintervention at 4 years was similar between groups (p = 0.98). TPVR could not be placed in 34 patients either due to coronary compression or excessive outflow tract diameter. SPVR patients had longer hospital length of stay (4.1 ± 1.8 days versus 1.2 ± 0.7 days; p < 0.001). TPVR patients had higher rates of infective endocarditis (4.8% versus 0%; p < 0.001) and overall hospital costs ($57,221 ± $13091 versus $44,366 ± $16,519; p < 0.001). CONCLUSIONS: Hemodynamic performance is similar between SPVR and TPVR with similar rates of reintervention. While SPVR patients have a longer hospital length of stay, TPVR was associated with higher rates of infective endocarditis, hospital costs, and failure to implant.