Successful explantation of children from the Berlin Heart EXCOR® ventricular assist device: A systematic review.

BACKGROUND: The Berlin Heart EXCOR® (BHE) can bridge children with severe heart failure to transplantation, but some are successfully weaned and spared transplantation. This study seeks to identify characteristics of children amenable to successful explantation with BHE support. METHODS: Preferred Reporting Items for Systematic reviews and Meta-Analyses 2020 guidelines were used. Five databases were screened for original, English articles measuring BHE support in patients <18 years old based on title and abstract. Exclusion criteria were applied: full-text availability, <10 total pediatric BHE patients, zero successful explantations from BHE, nonprimary literature, adult and pediatric results that could not be separated, and studies with overlapping patient information. Studies were analyzed with descriptive statistics. RESULTS: From 41 857 potential studies, 14 were analyzed with data from 58 hospitals on four continents from 1990 to 2020. There were 984 BHE patients. The most common diagnosis was dilated cardiomyopathy (n = 318, 32.3%), followed by congenital heart disease (n = 249, 25.3%). There were 85 (8.6%) children explanted with favorable outcomes. The underlying diagnosis was known in 44 (51.8%) cases: 14 (8.4%) of 166 cardiomyopathies, 17 (48.6%) of 35 myocarditis, and 12 (16.7%) of 72 with congenital heart disease were explanted. When the type of support was known, the rate of LVAD patients explanted was 21.3% (n = 19/89) and 2.4% (n = 1/42) of BiVAD patients were explanted. CONCLUSION: Explantation from BHE is not uncommon at 8.6%, but significant variation exists in the explantation data reported. Myocarditis and LVAD support may be populations suitable for weaning. Standardization of reporting measures and prospective registries may help identify patients suitable for this alternative to transplant and help develop weaning protocols.

Impact of electrophysiologists at daily multidisciplinary report in a paediatric cardiac care unit.

BACKGROUND: Paediatric cardiac electrophysiologists are essential in CHD inpatient care, but their involvement is typically limited to consultation with individual patients. In our integrated heart centre, an electrophysiologist reviews all cardiac inpatient telemetry over the preceding 24 hours and participates in daily multidisciplinary morning report. This study investigates the impact of the strategy of consistent, formalised electrophysiologist presence at multidisciplinary morning report. METHODS: This is a single-centre, prospective, observational study of electrophysiologist participation in patient encounters during heart centre multidisciplinary morning report from 10/20/2021 to 10/31/2022. Multidisciplinary morning report includes discussion of all intensive care and non-intensive care cardiac patients. An encounter was defined as reporting on one patient for one day. Electrophysiologists were initially blinded to observations. RESULTS: Two electrophysiologists were observed over 215 days encompassing 6413 patient encounters. Electrophysiologists made comments on 581(9.1%) encounters in 234 unique patients with diverse diagnoses, equating to a median of 3[interquartile range:1-4] encounters per day. These included identifications of arrhythmias and describing electrocardiographic findings. Recommendation to change management occurred in 282(48.5%) encounters, most commonly regarding medications (n = 142, 24.4%) or pacemaker management (n = 48, 8.3%). Of the 581 encounters, there were 61(10.5%) in which they corrected another physician's interpretation of rhythm or electrocardiogram. CONCLUSION: Routine electrophysiologist involvement in multidisciplinary morning report provides significant, frequent, and timely input in patient management by identifying precise rhythm-related diagnoses and allowing nuanced, patient-specific medication and pacemaker management of all cardiac patients, not just those consulted. Electrophysiologist presence at multidisciplinary morning report is a vital resource and this practice should be considered at integrated paediatric cardiac centres.

Evaluating variation in pre-operative evaluation and planning for children undergoing atrial or ventricular septal defect repair.

BACKGROUND: CHD care is resource-intensive. Unwarranted variation in care may increase cost and result in poorer health outcomes. We hypothesise that process variation exists within the pre-operative evaluation and planning process for children undergoing repair of atrial septal defect or ventricular septal defect and that substantial variation occurs in a small number of care points. METHODS: From interviews with staff of an integrated congenital heart centre, an initial process map was constructed. A retrospective chart review of patients with isolated surgical atrial septal defect and ventricular septal defect repair from 7/1/2018 through 11/1/2020 informed revisions of the process map. The map was assessed for points of consistency and variability. RESULTS: Thirty-two surgical atrial septal defect/ventricular septal defect repair patients were identified. Ten (31%) were reviewed by interventional cardiology before surgical review. Of these, 6(60%) had a failed catheter-based closure and 4 (40%) were deemed inappropriate for catheter-based closure. Thirty (94%) were reviewed in case conference, all attended surgical clinic, and none were admitted prior to surgery. The process map from interviews alone identified surgery rescheduling as a point of major variability; however, chart review revealed this was not as prominent a source of variability as pre-operative interventional cardiology review. CONCLUSIONS: Significant variation in the pre-operative evaluation and planning process for surgical atrial septal defect/ventricular septal defect patients was identified. If such process variation is widespread through CHD care, it may contribute to variations in outcome and cost previously documented within CHD surgery. Future research will focus on determining whether the variation is warranted or unwarranted, associated health outcomes and cost variation attributed to these variations in care processes.

Analysis of haemodynamics surrounding blood transfusions after the arterial switch operation: a pilot study utilising real-time telemetry high-frequency data capture.

BACKGROUND: Packed red blood cell transfusions occur frequently after congenital heart surgery to augment haemodynamics, with limited understanding of efficacy. The goal of this study was to analyse the hemodynamic response to packed red blood cell transfusions in a single cohort, as "proof-of-concept" utilising high-frequency data capture of real-time telemetry monitoring. METHODS: Retrospective review of patients after the arterial switch operation receiving packed red blood cell transfusions from 15 July 2020 to 15 July 2021. Hemodynamic parameters were collected from a high-frequency data capture system (SickbayTM) continuously recording vital signs from bedside monitors and analysed in 5-minute intervals up to 6 hours before, 4 hours during, and 6 hours after packed red blood cell transfusions-up to 57,600 vital signs per packed red blood cell transfusions. Variables related to oxygen balance included blood gas co-oximetry, lactate levels, near-infrared spectroscopy, and ventilator settings. Analgesic, sedative, and vasoactive infusions were also collected. RESULTS: Six patients, at 8.5[IQR:5-22] days old and weighing 3.1[IQR:2.8-3.2]kg, received transfusions following the arterial switch operation. There were 10 packed red blood cell transfusions administered with a median dose of 10[IQR:10-15]mL/kg over 169[IQR:110-190]min; at median post-operative hour 36[IQR:10-40]. Significant increases in systolic and mean arterial blood pressures by 5-12.5% at 3 hours after packed red blood cell transfusions were observed, while renal near-infrared spectroscopy increased by 6.2% post-transfusion. No significant changes in ventilation, vasoactive support, or laboratory values related to oxygen balance were observed. CONCLUSIONS: Packed red blood cell transfusions given after the arterial switch operation increased arterial blood pressure by 5-12.5% for 3 hours and renal near-infrared spectroscopy by 6.2%. High-frequency data capture systems can be leveraged to provide novel insights into the hemodynamic response to commonly used therapies such as packed red blood cell transfusions after paediatric cardiac surgery.

Hospitalisations of children and adults with Hypoplastic Left Heart Syndrome in Texas from 2009 to 2019.

INTRODUCTION: Hypoplastic Left Heart Syndrome accounts for a significant proportion of CHD morbidity and mortality, despite improvements in care and improved survival. This study evaluates number of, reasons for, and trends in discharges of patients with hypoplastic left heart syndrome over 11 years in Texas. METHODS: The Texas Inpatient Discharge Dataset Public Use File captures almost all discharges in Texas and was reviewed from 2009 to 2019. Discharges of patients ≥5 years of age and diagnosis codes for Hypoplastic Left Heart Syndrome were included. The admitting and principle diagnoses were categorised and all discharges were evaluated for procedures performed. Descriptive and univariate statistical analyses were performed. RESULTS: A total of 1024 discharges were identified with a 16.9% annual increase over the study period. Median length of stay was 4 [IQR: 2-8] and there were 17 (1.7%) in-hospital mortalities with no differences across age groups. Seven (17.1%) discharges of patients 25+ years were uninsured, higher than other age groups (p < 0.001). The most common admitting diagnosis was CHD and 224 (21.9%) of discharges included a procedure, including 23 heart transplants. Discharges occurred from 67 different hospitals with 4 (6.0%) representing 71.4% of all discharges. CONCLUSIONS: Discharges of Hypoplastic Left Heart Syndrome have increased rapidly, particularly in the older age groups and were spread over a large number of hospitals. Further work is needed to understand the interplay between Hypoplastic Left Heart Syndrome and other conditions and care experiences that occur within the general population, which will become more common as this population ages and grows.

Trisomy 18: disparities of care and outcomes in the State of Texas between 2009 and 2019.

OBJECTIVE: To perform a statewide characteristics and outcomes analysis of the Trisomy 18 (T18) population and explore the potential impact of associated congenital heart disease (CHD) and congenital heart surgery. STUDY DESIGN: Retrospective review of the Texas Hospital Inpatient Discharge Public Use Data File between 2009 and 2019, analysing discharges of patients with T18 identified using ICD-9/10 codes. Discharges were linked to analyse patients. Demographic characteristics and available outcomes were evaluated. The population was divided into groups for comparison: patients with no documentation of CHD (T18NoCHD), patients with CHD without congenital heart surgery (T18CHD), and patients who underwent congenital heart surgery (T18CHS). RESULTS: One thousand one hundred fifty-six eligible patients were identified: 443 (38%) T18NoCHD, 669 (58%) T18CHD, and 44 (4%) T18CHS. T18CHS had a lower proportion of Hispanic patients (n = 9 (20.45%)) compared to T18CHD (n = 315 (47.09%)), and T18NoCHD (n = 219 (49.44%)) (p < 0.001 for both). Patients with Medicare/Medicaid insurance had a 0.42 odds ratio (95%CI: 0.20-0.86, p = 0.020) of undergoing congenital heart surgery compared to private insurance. T18CHS had a higher median total days in-hospital (47.5 [IQR: 12.25-113.25] vs. 9 [IQR: 3-24] and 2 [IQR: 1-5], p < 0.001); and a higher median number of admissions (n = 2 [IQR: 1-4]) vs. 1 [IQR: 1-2] and 1 [IQR: 1-1], (p < 0.001 for both). However, the post-operative median number of admissions for T18CHS was 0 [IQR: 0-2]. After the first month of life, T18CHS had freedom from in-hospital mortality similar to T18NoCHD and superior to T18CHD. CONCLUSIONS: Short-term outcomes for T18CHS patients are encouraging, suggesting a freedom from in-hospital mortality that resembles the T18NoCHD. The highlighted socio-economic differences between the groups warrant further investigation. Development of a prospective registry for T18 patients should be a priority for better understanding of longer-term outcomes.

Experiences and insights from partners of individuals with single-ventricle CHD: a pilot qualitative research study.

INTRODUCTION: With advances in care, an increasing number of individuals with single-ventricle CHD are surviving into adulthood. Partners of individuals with chronic illness have unique experiences and challenges. The goal of this pilot qualitative research study was to explore the lived experiences of partners of individuals with single-ventricle CHD. METHODS: Partners of patients ≥18 years with single-ventricle CHD were recruited and participated in Experience Group sessions and 1:1 interviews. Experience Group sessions are lightly moderated groups that bring together individuals with similar circumstances to discuss their lived experiences, centreing them as the experts. Formal inductive qualitative coding was performed to identify salient themes. RESULTS: Six partners of patients participated. Of these, four were males and four were married; all were partners of someone of the opposite sex. Themes identified included uncertainty about their partners' future health and mortality, becoming a lay CHD specialist, balancing multiple roles, and providing positivity and optimism. Over time, they took on a role as advocates for their partners and as repositories of medical history to help navigate the health system. Despite the uncertainties, participants described championing positivity and optimism for the future. CONCLUSIONS: In this first-of-its-kind pilot study, partners of individuals with single-ventricle CHD expressed unique challenges and experiences in their lives. There is a tacit need to design strategies to help partners cope with those challenges. Further larger-scale research is required to better understand the experiences of this unique population.

Arrhythmias Requiring ECMO in Infants Without Structural Congenital Heart Disease.

Arrhythmias account for 55 per 100,000 patient evaluations in pediatric emergency departments. Most arrhythmias in children are amenable to medical management or cardioversion. Rarely, arrhythmias lead to significant hemodynamic instability requiring extracorporeal membrane oxygenation (ECMO) support. This study seeks to evaluate children under 1 year of age with a structurally normal heart requiring ECMO for an arrhythmia. This is a retrospective review of the Extracorporeal Life Support Organization Registry. All patients less than 1 year of age between 2009 and 2019 with a diagnosis of arrhythmia and without a diagnosis of structural heart malformation were included. Demographics, clinical characteristics, and outcomes were assessed with descriptive statistics and univariate and multivariable analyses. A total of 140 eligible patients were identified from the dataset. The most common arrhythmia was supraventricular tachycardia (SVT) in 70 (50%) patients. ECMO complications occurred in 106 (76.3%) patients and survival to discharge was achieved in 120 (85.7%) patients. In-hospital mortality was associated with neuromuscular blockade prior to ECMO [aOR 10.0 (95% CI 2.95-41.56), p < 0.001], neurologic ECMO complication [aOR 28.1 (95% CI 6.6-155.1), p < 0.001], and race with white race being protective [aOR 0.13, (95% CI 0.02-0.21), p = 0.002]. Similar survival and complication rates were found in subgroup analysis of SVT arrhythmias alone. Arrhythmias necessitating ECMO support in infants without structural congenital heart disease is a rare occurrence. However, survival to hospital discharge is favorable at greater than 85%. Given the favorable survival, earlier and more aggressive utilization of ECMO may result in improved outcomes.

Standard CPR versus interposed abdominal compression CPR in shunted single ventricle patients: comparison using a lumped parameter mathematical model.

INTRODUCTION: Cardiopulmonary resuscitation (CPR) in the shunted single-ventricle population is associated with poor outcomes. Interposed abdominal compression-cardiopulmonary resuscitation, or IAC-CPR, is an adjunct to standard CPR in which pressure is applied to the abdomen during the recoil phase of chest compressions. METHODS: A lumped parameter model that represents heart chambers and blood vessels as resistors and capacitors was used to simulate blood flow in both Blalock-Taussig-Thomas and Sano circulations. For standard CPR, a prescribed external pressure waveform was applied to the heart chambers and great vessels to simulate chest compressions. IAC-CPR was modelled by adding phasic compression pressure to the abdominal aorta. Differential equations for the model were solved by a Runge-Kutta method. RESULTS: In the Blalock-Taussig-Thomas model, mean pulmonary blood flow during IAC-CPR was 30% higher than during standard CPR; cardiac output increased 21%, diastolic blood pressure 16%, systolic blood pressure 8%, coronary perfusion pressure 17%, and coronary blood flow 17%. In the Sano model, pulmonary blood flow during IAC-CPR increased 150%, whereas cardiac output was improved by 13%, diastolic blood pressure 18%, systolic blood pressure 8%, coronary perfusion pressure 15%, and coronary blood flow 14%. CONCLUSIONS: In this model, IAC-CPR confers significant advantage over standard CPR with respect to pulmonary blood flow, cardiac output, blood pressure, coronary perfusion pressure, and coronary blood flow. These results support the notion that single-ventricle paediatric patients may benefit from adjunctive resuscitation techniques, and underscores the need for an in-vivo trial of IAC-CPR in children.

Accuracy of computed tomography angiography and structured reporting of high-risk morphology in anomalous aortic origin of coronary artery: comparison with surgery.

BACKGROUND: Morphological features including interarterial course, intramural course, high ostial location and slit-like ostium are presumed risk factors for sudden cardiac death in children with anomalous aortic origin of the coronary artery (AAOCA). To facilitate clinical risk stratification, the diagnostic accuracy of CT angiography for individual risk factors in the setting of AAOCA must be established. OBJECTIVE: We assessed diagnostic accuracy of standardized CT angiography interpretation for morphological characteristics that might determine risk in children with AAOCA by comparing them to surgical findings. MATERIALS AND METHODS: We created a standardized protocol for CT angiography of AAOCA and retrospectively evaluated diagnostic performance in 25 consecutive surgical patients. Relevant morphological variables in AAOCA were assessed by three independent blinded readers, with surgery as the reference standard. We used Cohen kappa coefficients and accuracies to assess agreement between readers and surgical findings, and we calculated intraclass correlation coefficients to compare length of the intramural course. RESULTS: CT angiography correctly identified AAOCA in all patients. For the three readers, accuracies for detecting ostial stenosis were 84%, 94% and 96%; for high ostial origin, accuracies were 76%, 78% 82%; for intramurality using the peri-coronary fat sign, accuracies were 98%, 96% and 92%; and for intramurality using oval shape of coronary artery, accuracies were 98%, 94% and 92%. The intraclass correlation coefficients (ICCs) for predicting intramural length among the three readers were 0.67, 0.75 and 0.81 using peri-coronary fat, and 0.69, 0.50 and 0.81 using oval shape, respectively. CONCLUSION: CT angiography reliably identified AAOCA in all children and detected the presence of intramurality with high accuracy.

Variables Prevalent Among Early Unplanned Readmissions in Infants Following Congenital Heart Surgery.

Medically complex children including infants undergoing cardiac surgery are at increased risk for hospital readmissions. Investigation of this population may reveal opportunities to optimize systems and coordination of care. A retrospective study of all infants undergoing cardiac surgery from 2015 through 2016 at a large tertiary institution who were readmitted within 1 year of discharge from cardiac surgical hospitalization was performed. Data specific to patient characteristics, surgical hospitalization, and readmission hospitalization are described. Unplanned readmissions within 1 year of hospital discharge were analyzed with Cox proportional hazard regression to identify factors associated with increased hazard for earlier unplanned readmission. Comparable to previous reports, 12% (78/658) of all surgical hospitalizations were associated with unplanned readmission within 30 days. Infectious etiology, followed by cardiac and gastrointestinal problems, was the most common reasons for unplanned 30-day readmission. Unplanned readmissions within 2 weeks of discharge were multifactorial and less commonly related to cardiac or surgical care. Primary nasogastric tube feeding at the time of discharge was the only significant risk factor for earlier unplanned readmission (p = 0.032) on multivariable analysis. Increased care coordination with particular attention to feeding and comorbidity management may be future targets to effectively mitigate readmissions and improve quality of care in this population.

Impact of Treatment Strategy on Outcomes in Isolated Pulmonary Artery of Ductal Origin.

Isolated pulmonary artery (PA) of ductal origin (IPADO) is a rare cardiac defect which requires surgical repair, with or without preceding palliation. We sought to determine the impact of treatment strategy on outcomes. Retrospective study of consecutive patients with IPADO that underwent staged or primary repair from 1/05 to 9/16 at 6 Congenital Cardiac Research Collaborative centers. Patients with single ventricle physiology, major aortopulmonary collaterals, or bilateral IPADO were excluded. Primary outcome was isolated PA z-score at late follow-up. Secondary outcomes included PA symmetry index (isolated:confluent PA diameter) and reintervention burden. Propensity score adjustment was used to account for baseline differences. Of 60 patients in the study cohort, 26 (43%) underwent staged and 34 (57%) primary repair. The staged and primary repair groups differed in weight at diagnosis and presence of other heart disease but not in baseline PA dimensions. Staged patients underwent ductal stent (n = 16) or surgical shunt (n = 10) placement followed by repair at 210 vs. 21 days in the primary repair group (p < 0.001). At median follow-up of 4.5 years post-repair, after adjustment, isolated PA z-score (- 0.74 [- 1.75, - 0.26] vs. - 1.95 [- 2.91, - 1.59], p = 0.012) and PA symmetry index (0.81 [0.49, 1.0] vs. 0.55 [0.48, 0.69], p = 0.042) significantly favored the staged repair group. Freedom from PA reintervention was not different between groups (adjusted HR 0.78 [0.41, 1.48]; p = 0.445). A staged approach to repair of IPADO is associated with superior isolated PA size and symmetry at late follow-up. Consideration should be given to initial palliation in IPADO patients, when feasible.

The intraoperative use of recombinant activated factor VII in arterial switch operations.

BACKGROUND: The rate of bleeding complications following arterial switch operation is too low to independently justify a prospective randomised study for benefit from recombinant factor VIIa. We aimed to evaluate factor VIIa in a pilot study. METHODS: We performed a retrospective cohort study of patients undergoing arterial switch operation from 2012 to 2017. Nearest-neighbour propensity score matching on age, gender, weight, and associated cardiac defects was used to match 27 controls not receiving recombinant factor VIIa to 30 patients receiving recombinant factor VIIa. Fisher's exact test was performed to compare categorical variables. Wilcoxon's rank-sum test was used to compare continuous variables between cohorts. RESULTS: Post-operative thrombotic complications were not associated with factor VIIa administration (Odds Ratio (OR) 0.28, 95% CI 0.005-3.77, p = 0.336), nor was factor VIIa administration associated with any re-explorations for bleeding. No intraoperative transfusion volumes were different between the recombinant factor VIIa cohort and controls. Post-operative prothrombin time (10.8 [10.3-12.3] versus 15.9 [15.1-17.2], p < 0.001) and international normalised ratio (0.8 [0.73-0.90] versus 1.3 [1.2-1.4], p < 0.001]) were lower in recombinant factor VIIa cohort relative to controls. CONCLUSIONS: In spite of a higher post-bypass packed red blood cell transfusion requirement, patients receiving recombinant factor VIIa had a similar incidence of bleeding post-operatively. With no difference in thrombotic complications, and with improved post-operative laboratory haemostasis, a prospective randomised study is warranted to evaluate recombinant factor VIIa.

Registry-based trials: a potential model for cost savings?

BACKGROUND/AIMS: Registry-based trials have emerged as a potentially cost-saving study methodology. Early estimates of cost savings, however, conflated the benefits associated with registry utilisation and those associated with other aspects of pragmatic trial designs, which might not all be as broadly applicable. In this study, we sought to build a practical tool that investigators could use across disciplines to estimate the ranges of potential cost differences associated with implementing registry-based trials versus standard clinical trials. METHODS: We built simulation Markov models to compare unique costs associated with data acquisition, cleaning, and linkage under a registry-based trial design versus a standard clinical trial. We conducted one-way, two-way, and probabilistic sensitivity analyses, varying study characteristics over broad ranges, to determine thresholds at which investigators might optimally select each trial design. RESULTS: Registry-based trials were more cost effective than standard clinical trials 98.6% of the time. Data-related cost savings ranged from $4300 to $600,000 with variation in study characteristics. Cost differences were most reactive to the number of patients in a study, the number of data elements per patient available in a registry, and the speed with which research coordinators could manually abstract data. Registry incorporation resulted in cost savings when as few as 3768 independent data elements were available and when manual data abstraction took as little as 3.4 seconds per data field. CONCLUSIONS: Registries offer important resources for investigators. When available, their broad incorporation may help the scientific community reduce the costs of clinical investigation. We offer here a practical tool for investigators to assess potential costs savings.

Enhancing efficiency and scientific impact of a clinical trials network: the Pediatric Heart Network Integrated CARdiac Data and Outcomes (iCARD) Collaborative.

Recent years have seen an exponential increase in the variety of healthcare data captured across numerous sources. However, mechanisms to leverage these data sources to support scientific investigation have remained limited. In 2013 the Pediatric Heart Network (PHN), funded by the National Heart, Lung, and Blood Institute, developed the Integrated CARdiac Data and Outcomes (iCARD) Collaborative with the goals of leveraging available data sources to aid in efficiently planning and conducting PHN studies; supporting integration of PHN data with other sources to foster novel research otherwise not possible; and mentoring young investigators in these areas. This review describes lessons learned through the development of iCARD, initial efforts and scientific output, challenges, and future directions. This information can aid in the use and optimisation of data integration methodologies across other research networks and organisations.

Reoperation after isolated subaortic membrane resection.

BACKGROUND: The resection of a subaortic membrane remains far from a curative operation. We sought to examine factors associated with reoperation and the degree of aortic valve regurgitation as a potential long-term source for reoperation. METHODS: All patients who underwent resection of an isolated subaortic membrane between 1995 and 2018 were included. Patients who underwent other procedures were excluded. Paired categorical data were compared using McNemar's test. Univariate time-to-event analyses were performed using Kaplan-Meier methods with log-rank tests for categorical variables and univariate Cox models for continuous variables. RESULTS: A total of 84 patients (median age 6.6, 31% females) underwent resection of isolated subaortic membrane. At a median follow-up of 9.3 years (interquartile range 0.6-22.5), 12 (14%) patients required one reoperation and 1 patient required two reoperations. Median time to first reoperation was 4.6 years. The degree of aortic valve regurgitation improved post-operatively from pre-operatively (p = 0.0007); however, the degree of aortic valve regurgitation worsened over the course of follow-up (p = 0.010) to equivalence with pre-operative aortic valve regurgitation (p = 0.18). Performance of a septal myectomy was associated with longer freedom from reoperation (p = 0.004). CONCLUSIONS: In patients with isolated subaortic membranes, performance of a septal myectomy can minimise risk for reoperation. Patients should be serially monitored for degradation of the aortic valve, even if aortic regurgitation is not present post-operatively.

Circumflex aorta with double aortic arch in an infant.

Circumflex aorta and double aortic arch are two forms of rare vascular rings. We present a case of an infant who was diagnosed with circumflex aorta and double aortic arch, and describe the surgical management of this rare anomaly.

Acute humoral rejection in an infant without risk factors after heart transplantation.

Graft rejection is the most common factor that limits graft survival after transplantation. During infancy, the humoral immune system is partially suppressed and humoral rejection of a cardiac allograft has not been reported in the absence of risk factors such as prior transplantation, blood transfusions, ventricular assist devices, and elevation of panel reactive antibodies. We present a case of an infant with dilated cardiomyopathy who developed multiple episodes of acute humoral rejection after heart transplantation in the absence of risk factors.

A pulmonary artery sling with a vascular ring in a toddler: an uncommon combination.

Pulmonary artery slings and vascular rings are very rare congenital anomalies. It is even rarer to have both anomalies in the same setting. We present a case of a toddler who was diagnosed with a left pulmonary artery sling and a vascular ring as part of the screening process for the VACTERL association - co-occurrence of vertebral, anorectal, cardiac, tracheoesophageal, renal, and limb malformations. He underwent a successful surgical repair via median sternotomy and on cardiopulmonary bypass with an uneventful postoperative course.

Familial clustering of cardiac conditions in patients with anomalous aortic origin of a coronary artery and myocardial bridges.

BACKGROUND: Anomalous aortic origin of a coronary artery is the second leading cause of sudden cardiac arrest/death in young athletes in the United States of America. Limited data are available regarding family history in this patient population. METHODS: Patients were evaluated prospectively from 12/2012 to 02/2017 in the Coronary Anomalies Program at Texas Children's Hospital. Relevant family history included the presence of CHD, sudden cardiac arrest/death, arrhythmia/pacemaker use, cardiomyopathy, and atherosclerotic coronary artery disease before the age of 50 years. The presence of one or more of these in 1st- or 2nd-degree relatives was considered significant. RESULTS: Of 168 unrelated probands (171 patients total) included, 36 (21%) had significant family history involving 19 (53%) 1st-degree and 17 (47%) 2nd-degree relatives. Positive family history led to cardiology referral in nine (5%) patients and the presence of abnormal tests/symptoms in the remaining patients. Coronary anomalies in probands with positive family history were anomalous right (27), anomalous left (five), single right coronary artery (two), myocardial bridge (one), and anomalous circumflex coronary artery (one). Conditions present in their family members included sudden cardiac arrest/death (15, 42%), atherosclerotic coronary artery disease (14, 39%), cardiomyopathy (12, 33%), CHD (11, 31%), coronary anomalies (3, 8%), myocardial bridge (1, 3%), long-QT syndrome (2, 6%), and Wolff-Parkinson-White (1, 3%). CONCLUSION: In patients with anomalous aortic origin of a coronary artery and/or myocardial bridges, there appears to be familial clustering of cardiac diseases in approximately 20% of patients, half of these with early occurrence of sudden cardiac arrest/death in the family.