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Redo sternotomy and explantation of left ventricular assist devices (LVAD) for heart transplantation (HT) involve prolonged dissection, potential injury to mediastinal structures and/or bleeding. Our study compared a complete expanded polytetrafluoroethylene (ePTFE) wrap versus minimal or no ePTFE during LVAD implantation, on outcomes of subsequent HT.Between July 2005 and July 2018, 84 patients underwent a LVAD implant and later underwent HT. Thirty patients received a complete ePTFE wrap during LVAD implantation (Group 1), and 54 patients received either a sheet of ePTFE placed in the anterior mediastinum or no ePTFE (Group 2).Baseline characteristics were similar between Groups 1 and 2. Surgeons reported subjective improvements in speed, predictability, and safety of dissection with complete ePTFE compared with minimal or no ePTFE. Time from incision to initiation of cardiopulmonary bypass (CPB) were similar between groups (97 ± 38 vs. 89 ± 29 min, p = .3). Injury to mediastinal structures during the dissection was similar between groups (10% vs. 11%, p .9). While surgeons reported less intraoperative bleeding in Group 1 (43% vs. 61%), this trend did not reach significance (p = .1). In-hospital mortality, intensive care unit length of stay and hospital length of stay were similar between both groups.In patients undergoing LVAD explant-HT, there was a trend toward reduced surgeon reported intraoperative bleeding with ePTFE placement. Despite qualitatively reported greater ease and speed of mediastinal dissection with ePTFE membrane placement, time to initiation of CPB did not differ, likely because surgeons remained cautious, allowing extra time for unanticipated difficulties.

Purpose of review To review anomalous aortic origin of a coronary artery (AAOCA) anatomy, prevalence, mechanism and risk of ischemia, presentation, evaluation, management, and future directions. Recent findings Although most anatomic variants of AAOCA are benign, a small number are associated with increased risk of sudden death. A complete evaluation, including the use of advanced noninvasive imaging and provocative testing should be performed on nearly every patient with AAOCA. On the basis of recent studies, the ischemic risk appears to be greatest with a left anomalous coronary artery but an anomalous right coronary artery is not benign. Other risk factors include: a left anomalous coronary with an intramural course, high take-off, or slit-like orifice, and a right anomalous coronary with a longer intramural course. Exercise restriction is rarely recommended. Management primarily consists of nonoperative care, or surgical repair in those who are symptomatic or who have high-risk variants. Surgery itself continues to evolve; however, it is not benign, with a higher than expected chance of morbidity. Summary Advances have been made over the past decade regarding management of patients with AAOCA; however, the mechanism of ischemia and ability to predict risk is still incompletely understood. Management decisions should be based on anatomy, results of investigations, and shared decision-making with patients and their families. Surgery may be recommended for those at higher risk and should be done at centers experienced in AAOCA surgery. Future research should be collaborative in order to share experiences and insights to help advance our understanding of risk and ultimately to improve patient management.

Objectives Redo sternotomy and explantation of left ventricular assist devices (LVAD) for heart transplantation (HT) involve prolonged dissection, potential injury to mediastinal structures and/or bleeding. Our study compared a complete expanded polytetrafluoroethylene (ePTFE) wrap versus minimal or no ePTFE during LVAD implantation, on outcomes of subsequent HT. Methods Between July 2005 and July 2018, 84 patients underwent a LVAD implant and later underwent HT. Thirty patients received a complete ePTFE wrap during LVAD implantation (Group 1), and 54 patients received either a sheet of ePTFE placed in the anterior mediastinum or no ePTFE (Group 2). Results Baseline characteristics were similar between Groups 1 and 2. Surgeons reported subjective improvements in speed, predictability and safety of dissection with complete ePTFE compared with minimal or no ePTFE. Time from incision to initiation of cardiopulmonary bypass (CPB) were similar between groups (97±38 min vs 89±29 min, p=0.3). Injury to mediastinal structures during the dissection was similar between groups (10% vs 11%, p>0.9). While surgeons reported less intraoperative bleeding in Group 1 (43% vs 61%), this trend did not reach significance (p=0.1). In-hospital mortality, ICU length of stay and hospital length of stay were similar between both groups. Conclusions In patients undergoing LVAD explant-HT, there was a trend towards reduced surgeon reported intraoperative bleeding with ePTFE placement. Despite qualitatively reported greater ease and speed of mediastinal dissection with ePTFE membrane placement, time to initiation of CPB did not differ, likely because surgeons remained cautious, allowing extra time for unanticipated difficulties.

Background and ObjectivesMachine Learning offers opportunities to improve patient outcomes, team performance, and reduce healthcare costs. Yet only a small fraction of all Machine Learning models for health care have been successfully integrated into the clinical space. There are no current guidelines for clinical model integration, leading to waste, unnecessary costs, patient harm, and decreases in efficiency when improperly implemented. Systems engineering is widely used in industry to achieve an integrated system of systems through an interprofessional collaborative approach to system design, development, and integration. We propose a framework based on systems engineering to guide the development and integration of Machine Learning models in healthcare.MethodsApplied systems engineering, software engineering and health care Machine Learning software development practices were reviewed and critically appraised to establish an understanding of limitations and challenges within these domains. Principles of systems engineering were used to develop solutions to address the identified problems. The framework was then harmonized with the Machine Learning software development process to create a systems engineering-based Machine Learning software development approach in the healthcare domain.ResultsWe present an integration framework for healthcare Artificial Intelligence that considers the entirety of this system of systems. Our proposed framework utilizes a combined software and integration engineering approach and consists of four phases: (1) Inception, (2) Preparation, (3) Development, and (4) Integration. During each phase, we present specific elements for consideration in each of the three domains of integration: The Human, The Technical System, and The Environment. There are also elements that are considered in the interactions between these domains.ConclusionClinical models are technical systems that need to be integrated into the existing system of systems in health care. A systems engineering approach to integration ensures appropriate elements are considered at each stage of model design to facilitate model integration. Our proposed framework is based on principles of systems engineering and can serve as a guide for model development, increasing the likelihood of successful Machine Learning translation and integration.

Kawasaki disease (KD) may lead to coronary artery aneurysms (CAA) with potential for thrombosis. We aimed to determine the bleeding risk during thromboprophylaxis regimens with dual and triple therapy.KD patients with medium to large CAAs receiving combination thromboprophylaxis therapy (dual or triple therapy with acetylsalicylic acid (ASA), clopidogrel, low molecular weight heparin (LMWH) or warfarin) were reviewed (1979-2017). Treatment periods30 days were excluded. Bleeding events were classified using the Bleeding Academic Research Consortium (BARC) Score. The incidence of bleeding events per patient year of exposure was determined for each regimen.n = 98 of 3022 KD (23 females:75 males) were included. Median age at diagnosis was 2.6 years (IQR: 0.6-6.2), median maximum CAA z-score was 18.0 (range: 5-65.5, IQR: 10.8-28.0, m = 6) and median follow-up duration was 6.5 years (IQR: 2.5-20.2). The incidence of type ≥2 bleeds per patient-year for each regimen was 0 (ASA + clopidogrel+LMWH), 0.03 (ASA + clopidogrel), 0.06 (ASA + warfarin), 0.06 (ASA + clopidogrel+warfarin), and 0.1 (ASA + LMWH) in ascending order. 31 bleeding events requiring medical attention (type ≥2) occurred in 30 patients (median age 7.8 years). Of the 17 type ≥2 bleeds on warfarin with an International Normalised Ratio (INR) available, 13 occurred with an INR3. For patients receiving triple therapy (dual antiplatelet with anticoagulant), there were 57 bleeding events over 20 treatment periods.The overall bleeding risk was low in KD patients receiving combination thromboprophylaxis, and not significantly different across all regimens. Type ≥2 bleeding events that occurred on warfarin were most frequently associated with high INR values.

Up to 25% of children with congenital heart disease are obese, which may have negative physiologic consequences for patients with repaired tetralogy of Fallot (rTOF).Patients with rTOF who underwent cardiac magnetic resonance (CMR) imaging and cardiopulmonary exercise testing from 2007 to 2018 were reviewed. Complex rTOF patients were excluded. Obese patients (body mass index [BMI] ≥ 95th percentile) were compared with normal-weight patients (BMI85th percentile). CMR data were indexed to actual body surface area (aBSA), height, and BSA assuming ideal body weight (iBSA).We compared 32 obese patients matched with 64 normal-weight patients. Obese vs normal-weight patients had significantly lower right (RV; median 45% [interquartile range 42%-48%] vs 52% [47%-55%]; P0.0001) and left (LV; 52% [47%-56%] vs 56% [54%-60%]; P0.0001) ventricular ejection fractions (EFs). There were no statistically significant differences regarding aBSA-indexed volumes of the RV or LV at either end-diastole (EDV) or end-systole (ESV). However, when indexed to either height or iBSA, obese patients had significantly greater RVEDV and LVEDV, greater LV mass, and higher RV and LV stroke volumes. Obese patients had lower peak oxygen consumption and oxygen consumption at anaerobic threshold. These results did not change after adjusting for degree of pulmonary regurgitation.Obesity is associated with increased biventricular size, decreased biventricular EFs, and impaired exercise performance after rTOF. These data suggest a potential role for cardiac rehabilitation for weight management and to optimize fitness.

BackgroundAbnormalities in heart rate variability (HRV) have been associated with increased morbidity and mortality. Adults with a history of successful correction of atrial septal defects (ASDs) and ventricular septal defects (VSDs) have clinically relevant abnormalities in HRV. The etiology of these abnormalities is unknown as is when they occur in the natural history of these lesions. We sought to determine whether the abnormalities described in adult patients are identifiable in pediatric patients.Materials and methodsEighty-five ASD patients, 105 VSD patients, and 142 non-cardiac surgical comparison patients aged 0–18 years were studied during post-operative admission to the critical care unit using continuously monitored bedside electrocardiographic (ECG) data.ResultsASD and VSD patients had statistically significantly lower time-domain heart rate variability parameters, i.e., standard deviation of NN interval duration, and lower frequency-domain heart rate variability parameters, i.e., power in the high frequency band and power in the low frequency band, compared to the comparison cohort. The lower frequency band to high frequency band power ratio was lower in ASD patients and higher in VSD patients compared to the comparison cohort. The abnormalities identified correlate well with patterns described in adult patients.ConclusionPost-surgical ASD and VSD patients have markedly abnormal heart rate variability patterns indicative of reduced parasympathetic activity and predominance of sympathetic activity. The HRV abnormalities described in adult patients are identifiable as early as the postoperative period in childhood. This finding warrants prospective study to identify drivers of this phenomenon.

To review anomalous aortic origin of a coronary artery (AAOCA) anatomy, prevalence, mechanism and risk of ischemia, presentation, evaluation, management, and future directions.Although most anatomic variants of AAOCA are benign, a small number are associated with increased risk of sudden death. A complete evaluation, including the use of advanced noninvasive imaging and provocative testing should be performed on nearly every patient with AAOCA. On the basis of recent studies, the ischemic risk appears to be greatest with a left anomalous coronary artery but an anomalous right coronary artery is not benign. Other risk factors include: a left anomalous coronary with an intramural course, high take-off, or slit-like orifice, and a right anomalous coronary with a longer intramural course. Exercise restriction is rarely recommended. Management primarily consists of nonoperative care, or surgical repair in those who are symptomatic or who have high-risk variants. Surgery itself continues to evolve; however, it is not benign, with a higher than expected chance of morbidity.Advances have been made over the past decade regarding management of patients with AAOCA; however, the mechanism of ischemia and ability to predict risk is still incompletely understood. Management decisions should be based on anatomy, results of investigations, and shared decision-making with patients and their families. Surgery may be recommended for those at higher risk and should be done at centers experienced in AAOCA surgery. Future research should be collaborative in order to share experiences and insights to help advance our understanding of risk and ultimately to improve patient management.

Background Improved survival for patients with dextro-transposition of the great arteries (d-TGA) has led to an increased focus on functional health status (FHS). We assessed late survival and patient-perceived FHS for repaired TGA patients. Methods From 1985-1990, 830 neonates admitted to 24 Congenital Heart Surgeons' Society (CHSS) institutions with d-TGA underwent repair, including 516 arterial switch, 110 Mustard, 175 Senning, and 29 Rastelli operations. Median follow-up was 24.0 years (range, 0-32.7 years). We performed multiphase parametric hazard analysis for death after repair. Patients completed Pediatric Quality of Life Inventory (PedsQL) Core Scales and Cardiac Module Adult Forms. Patient and operative factors and CHSS General Questionnaire responses were analyzed for association with FHS using multiple linear regression. Results Survival at 30 years after repair was arterial switch, 80% ± 2%; Mustard, 81% ± 5%; Senning, 70% ± 4%; and Rastelli, 86% ± 8%. The arterial switch had the lowest hazard for late death. TGA patients reported FHS similar to a healthy population in all domains except physical health (lower scores). Symptoms, including chest pain and fainting, and having a pacemaker were associated with lower, and being employed with higher, self-reported physical health. Arterial switch patients reported higher FHS than the atrial switch patients in all domains. Conclusions Arterial switch patients have a lower risk of premature death and better FHS than those with an atrial switch. Increased surveillance in atrial switch patients is warranted because of their increased risk of late death. Presence of symptoms, pacemaker, and lack of employment are associated with reduced FHS.

OBJECTIVES Physiologic signals are typically measured continuously in the critical care unit, but only recorded at intermittent time intervals in the patient health record. Low frequency data collection may not accurately reflect the variability and complexity of these signals or the patient's clinical state. We aimed to characterize how increasing the temporal window size of observation from seconds to hours modifies the measured variability and complexity of basic vital signs. DESIGN Retrospective analysis of signal data acquired between April 1, 2013, and September 30, 2015. SETTING Critical care unit at The Hospital for Sick Children, Toronto. PATIENTS Seven hundred forty-seven patients less than or equal to 18 years old (63,814,869 data values), within seven diagnostic/surgical groups. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS Measures of variability (SD and the absolute differences) and signal complexity (multiscale sample entropy and detrended fluctuation analysis [expressed as the scaling component α]) were calculated for systolic blood pressure, heart rate, and oxygen saturation. The variability of all vital signs increases as the window size increases from seconds to hours at the patient and diagnostic/surgical group level. Significant differences in the magnitude of variability for all time scales within and between groups was demonstrated (p < 0.0001). Variability correlated negatively with patient age for heart rate and oxygen saturation, but positively with systolic blood pressure. Changes in variability and complexity of heart rate and systolic blood pressure from time of admission to discharge were found. CONCLUSIONS In critically ill children, the temporal variability of physiologic signals supports higher frequency data capture, and this variability should be accounted for in models of patient state estimation.

Patients receiving a right ventricle to pulmonary artery conduit (PC) in infancy will require successive procedures or replacements, each with variable longevity. We sought to identify factors associated with time-related risk of a subsequent surgical replacement (PC3) or transcatheter pulmonary valve insertion (TPVI) after a second surgically placed PC (PC2).From 2002 to 2016, 630 patients from 29 Congenital Heart Surgeons' Society member institutions survived to discharge after initial valved PC insertion (PC1) at age ≤ 2 years. Of those, 355 underwent surgical replacement (PC2) of that initial conduit. Competing risk methodology and multiphase parametric hazard analyses were used to identify factors associated with time-related risk of PC3 or TPVI.Of 355 PC2 patients (median follow-up, 5.3 years), 65 underwent PC3 and 41 TPVI. Factors at PC2 associated with increased time-related risk of PC3 were smaller PC2 Z score (hazard ratio [HR] 1.6, P.001), concomitant aortic valve intervention (HR 7.6, P = .009), aortic allograft (HR 2.2, P = .008), younger age (HR 1.4, P.001), and larger Z score of PC1 (HR 1.2, P = .04). Factors at PC2 associated with increased time-related risk of TPVI were aortic allograft (HR: 3.3, P = .006), porcine unstented conduit (HR 4.7, P.001), and older age (HR 2.3, P = .01).Aortic allograft as PC2 was associated with increased time-related risk of both PC3 and TPVI. Surgeons may reduce risk of these subsequent procedures by not selecting an aortic homograft at PC2, and by oversizing the conduit when anatomically feasible.

Anomalous aortic origin of a coronary artery (AAOCA) is reported as the second leading cause of sudden cardiac death in otherwise healthy young individuals. Several surgical studies have reported a shallow operative risk, describing repair as safe and effective with short or medium-term follow-up. However, surgical repair can also be associated with a high risk of complications. Numerous repair techniques have been described in the literature, but each technique's indications and limitations are often not well-understood or understated. Since explicit technical knowledge of the most appropriate surgical technique is highly desirable, we sought to thoroughly and clearly outline the safeguards and pitfalls of the most common surgical techniques used to repair AAOCA.

As part of the PhysioNet/Computing in Cardiology Challenge 2020, we developed a model for multilabel classification of 12-lead electrocardiogram (ECG) data according to specified cardiac abnormalities. Our team, LaussenLabs, developed a novel classifier pipeline with 6 core features (1) the addition of r-peak, p-wave, and t-wave features that were input into the model along with the 12-lead data, (2) data augmentation, (3) competition metric hacking, (4) modified WaveNet architecture, (5) Sigmoid threshold tuning, and (6) model stacking. Our approach received a score of 0.63 using 6-fold cross-validation on the full training data. Unfortunately, our model was unable to run on the test dataset due to time constraints, therefore, our model's final test score is undetermined.

The controversy regarding the best or ideal surgical management of Tetralogy of Fallot (ToF) stems from the recognition of there being a spectrum of morphology and associated lesions, each of which require a different approach to achieve the three goals of minimizing mortality preserving right ventricular function long-term and minimizing reinterventions. A one-size-fits-all approach to ToF needs to be replaced by a considered and personalized approach in order to yield the best outcomes possible for individual patients. The great majority of patients with ToF undergo primary complete repair between age 3–9 months with excellent outcomes. However, the greatest challenge is the severely cyanotic neonates where primary repair is still associated with high mortality and reintervention rates. Risk factors are low weight and small/poorly developed pulmonary vasculature. High-risk neonates have better outcomes with palliation—but mortality is still high. Palliative interventions in the catherization lab are showing better outcomes than traditional BT shunt and the RVOT stent is emerging as potential game-changer. Primary neonatal repair is still recommended if weight >3 kg and Nakata >100 mm2/m2. However, neonates with low weight, small pulmonary arteries or multiple comorbidities (including ToF/AVSD and anomalous LAD) may do better with a staged approach, There is good argument for RVOT stenting as a bridge to complete repair due to its stable circulation without diastolic run off and volume loading of the circulation, and its potential to allow branch PA growth.

During repair of atrioventricular septal defect (AVSD), surgeons might leave an atrial level shunt when concerned about postoperative physiology, or as part of routine practice. However, the association of fenestration with outcomes is unclear. We sought to determine factors associated with mortality after biventricular repair of AVSD.We included 581 patients enrolled from 32 Congenital Heart Surgeons' Society institutions from January 1, 2012, to June 1, 2020 in the Congenital Heart Surgeons' Society AVSD cohort. Parametric multiphase hazard analysis was used to identify factors associated with mortality. A random effect model was used to account for possible intersite variability in mortality.An atrial fenestration was placed during repair in 133/581 (23%) patients. Overall 5-year survival after repair was 91%. Patients who had fenestration had an 83% 5-year survival versus 93% for those not fenestrated (P .001). Variables associated with mortality in multivariable hazard analysis included institutional diagnosis of ventricular unbalance (hazard ratio [HR], 2.7 [95% confidence interval (CI): 1.5-4.9]; P = .003), preoperative mechanical ventilation (HR, 4.1 [95% CI, 1.3-13.1]; P = .02), atrial fenestration (HR, 2.8 [95% CI, 1.5-4.9]; P .001), and reoperation for ventricular septal defect (HR, 4.0 [95% CI, 1.3-13.1]; P = .002). There was no difference in measures of ventricular unbalance for comparisons of fenestrated with nonfenestrated patients. No significant interinstitution variability in mortality was observed on the basis of the random effect model (P = .7).An atrial communication at biventricular repair of AVSD is associated with significantly reduced long-term survival after adjusting for other known associated factors, including unbalance. These findings might challenge the routine practice of fenestration.

Objective Biostatistics are frequently used in research published in the domain of cardiothoracic surgery. The objective of this study was to describe the scope of statistical techniques reported in the literature and to highlight implications for editorial review and critical appraisal. Methods Original research articles published between January and April 2017 in the Journal of Thoracic and Cardiovascular Surgery, Annals of Thoracic Surgery, and the European Journal of Cardio-Thoracic Surgery were examined. For each article, the statistical method(s) reported were recorded and categorized by complexity. Results We reviewed 293 articles that reported 1068 statistical methods. The mean number of different statistical methods reported per article was 3.6 ± 1.9, with variation by subspecialty and journal. The most common statistical methods were contingency tables (in 59% of articles), t tests (49%), and survival methods (49%). Only 4% of articles used descriptive statistics alone. An introductory level of statistical knowledge was deemed sufficient for understanding 16% of articles, whereas for the remainder a higher level of knowledge would be needed. Conclusions Contemporary cardiothoracic surgery research frequently requires the use of complex statistical methods. This was evident across articles for all cardiothoracic surgical subspecialties as reported in 3 high-impact journals. Routine review of manuscript submissions by biostatisticians is needed to ensure the appropriate use and reporting of advanced statistical methods in cardiothoracic surgery research.

OBJECTIVE Tricuspid atresia with normally related great vessels (TA) is considered the optimal substrate for the Fontan pathway. The factors associated with death or transplantation after cavopulmonary shunt (CPS) are underappreciated. We aimed to determine factors associated with CPS-Fontan interstage death/transplantation versus transition to Fontan in TA. METHODS A total of 417 infants younger than 3 months of age with TA were enrolled (January 1999 to February 2020) from 40 institutions into the Congenital Heart Surgeons' Society TA cohort. Parametric competing risk methodology was used to determine factors associated with the competing end points of death/transplantation without Fontan completion, and transition to Fontan. RESULTS CPS was performed in 382 patients with TA; of those, 5% died or underwent transplantation without transition to Fontan and 91% transitioned to Fontan by 5 years after CPS. Prenatal diagnosis (hazard ratio [HR], 0.74; P

Objectives Interventricular septal hematoma (IVSH) is a rare complication, which may result from ventricular septal defect (VSD) repair. IVSH can result in conduction and/or hemodynamic abnormalities related to impaired ventricular filling or outflow tract obstruction. We report the novel use of extracorporeal membrane oxygenation (ECMO) for management. Methods Echocardiography reports (January 1980 to December 2016) were searched for the term "hematoma" in our institutional database and reviewed to determine appropriate cases. Charts and imaging (reports) data were abstracted. All intraoperative and select postoperative echocardiograms were reread by a pediatric cardiologist. Results N = 12 patients with IVSH. Mean age and weight at surgery were 59 ± 41 days and 3.4 (2.9-5.1) kg, respectively, while the most frequent diagnosis was tetralogy of Fallot. Although all patients had intraoperative transesophageal echocardiography (TEE), only 55% (6 of 11, missing [m] = 1) of IVSH were discovered intraoperatively. Of the 5 patients not discovered intraoperatively (m = 1), IVSH was postoperatively detected secondary to arrhythmia/decompensation by echocardiogram 10.1 ± 7.9 hours postoperatively. Five patients (42%) were managed with ECMO (1 unable to separate from bypass). Overall mortality was 33%. For patients in whom ECMO was used, 2 of 5 (40%) survived. Mean time to IVSH resolution in all survivors was 20 ± 185 days. Conclusions IVSH from VSD repair can result in clinical decompensation and mortality. This may relate to the high proportion missed intraoperatively. ECMO should be considered an important modality, which can allow for IVSH resolution. However, considerations must be made to allow for appropriate anticoagulation to avoid hematoma expansion and repeat imaging during ECMO to continually assess the interventricular septum.

Objectives To analyze outcomes after pulmonary artery banding (PAB) in complete atrioventricular septal defect (AVSD), with a focus on surgical pathway outcome and timing, survival, and atrioventricular valve function. Methods PAB was performed in 50 of 474 infants (11%) from 28 institutions between 2012 and 2018 at a median age of 1.1 months. The median duration of follow-up was 2.1 years. Atrioventricular valve function was assessed by review of pre-PAB and predischarge echocardiograms (median, 9 days postoperatively). Competing-risks methodology was used to analyze the risks for biventricular repair, univentricular repair, and death. Results At 2 years, the proportions of patients who underwent biventricular repair, univentricular repair, and death were 68%, 13%, and 12%, respectively, with 8% awaiting definitive repair. After PAB, atrioventricular valve regurgitation decreased in 14 infants and increased in 10, but the distribution of regurgitation severity did not change significantly in the total cohort or subgroups. The intended management plan at PAB was deferred biventricular/univentricular decision (23 infants), 2-stage biventricular repair (24 infants), and univentricular repair (3 infants). Among the 24 infants intended for biventricular repair, 23 achieved biventricular repair and 1 died before repair. Survival at 4 years after biventricular repair among patients with previous PAB (93%) was similar to the 4-year survival of the patients who underwent primary biventricular repair (91%; n = 333). Conclusions PAB is a successful strategy in complete AVSD to bridge to biventricular repair and has similar post-biventricular repair survival to primary biventricular repair. Changes in atrioventricular valve regurgitation after PAB were variable.

Objectives Improved survival has led to interest in functional health status (FHS) as patients with dextro-transposition of the great arteries (d-TGA) transition to adulthood. Our primary objectives were (1) evaluation of The Medical Outcomes Study Short Form-36 Health Survey (SF-36) results; (2) comparison with results of patients who completed the Child Health Questionnaire-Child Form 87 (CHQ-CF87) previously, or the PedsQL Generic Core Scales (PedsQL) survey subsequently; and (3) determination of factors associated with SF-36 domains. Methods Survivors from the d-TGA Congenital Heart Surgeons' Society cohort (1985-1989) completed the SF-36 (2010) as a measure of FHS (n = 210; age 21-26 years). Patient characteristics, medical history, psychosocial factors, and previous adolescent CHQ-CF87 FHS assessment (2000) were explored for association with SF-36 domains, along with comparison with recent PedsQL data (2017). Results Patients scored themselves the same/higher than published normative data in 10 of 10 SF-36 summary scores/domains and similar in 5 of 6 PedsQL summary scores/domains. Factors commonly associated with lower summary scores/domains of the SF-36 were presence of cardiac symptoms, heart condition impacting physical activity/overall health/quality of life, unemployment, and lack of postsecondary education. Less commonly associated factors were lower birth weight, greater total medication number, female sex, shorter procedure-free interval, poor health knowledge, lower family income, younger age at SF-36, living with parents, and being married. These factors accounted for 17% to 47% of the variation in FHS summary scores/domains. FHS was minimally related to d-TGA morphology and repair type. Conclusions Patients with d-TGA surviving into adulthood, regardless of morphology or repair type, can primarily expect normal FHS. Addressing the challenges of patients with d-TGA entering adulthood requires consideration of psychosocial factors and clinical management.

It remains unclear when sudden cardiac event risk outweighs surgical risk for patients with anomalous aortic origin of a coronary artery. The Congenital Heart Surgeons' Society sought to characterize the surgical risks by determining the techniques, complications, and outcomes of repair.Between January 2000 and September 2018, 682 patients with anomalous aortic origin of a coronary artery aged 30 years or less were enrolled. Demographic, morphologic, operative, imaging, and ischemia-related data were analyzed.There were 395 of 682 (57%) surgical patients (45 centers, median follow-up 2.8 years). In addition to primary repair (87% unroofing, 26% commissural manipulation), 13 patients had 15 coronary-related reoperations. Of 358 patients with pre/postoperative aortic insufficiency assessment, 27 (8%) developed new mild or greater aortic insufficiency postoperatively, and 7 (2%) developed new moderate or greater aortic insufficiency. Freedom from mild aortic insufficiency differed in those with versus without commissural manipulation (85%/91% at 6 months, 83%/90% at 1 year, and 77%/88% at 3 years, respectively) (P = .05). Of 347 patients with preoperative/postoperative ejection fraction, 6 (2%) developed new abnormal ejection fraction (50%) within 30 days of surgery which persisted. Although 64 of 395 patients (16%) had preoperative ischemia, after surgery 51 of 64 patients (80%) no longer had ischemia (13 = new postoperative ischemia, P .0001). Four patients died postoperatively (preoperatively 2 asymptomatic, 1 symptomatic, 1 in extremis). Composite surgical adverse event rates were 7% to 13% in the entire cohort (increasing/decreasing by presentation/anatomy/repair strategy).Anomalous aortic origin of a coronary artery surgery may relieve ischemia with low mortality; however, it can result in a variety of important morbidities, varying by the group evaluated. Strategies avoiding commissural manipulation may decrease the risk of developing aortic insufficiency. Understanding these risks should inform surgical decision-making and support the need for standardized assessment and management.

Objective Storage of physiological waveform data for retrospective analysis presents significant challenges. Resultant data can be very large, and therefore becomes expensive to store and complicated to manage. Traditional database approaches are not appropriate for large scale storage of physiological waveforms. Our goal was to apply modern time series compression and indexing techniques to the problem of physiological waveform storage and retrieval. Approach We deployed a vendor-agnostic data collection system and developed domain-specific compression approaches that allowed long term storage of physiological waveform data and other associated clinical and medical device data. The database (called AtriumDB) also facilitates rapid retrieval of retrospective data for high-performance computing and machine learning applications. Main results A prototype system has been recording data in a 42-bed pediatric critical care unit at The Hospital for Sick Children in Toronto, Ontario since February 2016. As of December 2019, the database contains over 720,000 patient-hours of data collected from over 5300 patients, all with complete waveform capture. One year of full resolution physiological waveform storage from this 42-bed unit can be losslessly compressed and stored in less than 300 GB of disk space. Retrospective data can be delivered to analytical applications at a rate of up to 50 million time-value pairs per second. Significance Stored data are not pre-processed or filtered. Having access to a large retrospective dataset with realistic artefacts lends itself to the process of anomaly discovery and understanding. Retrospective data can be replayed to simulate a realistic streaming data environment where analytical tools can be rapidly tested at scale.

We sought to determine anatomic features associated with evidence of myocardial ischemia and sudden cardiac events (arrest or death) for patients with anomalous aortic origin of a coronary artery.We enrolled 560 patients, less than or equal to 30 years, at diagnosis from 40 institutions. Ischemia was defined as the presence of exertional syncope, a sudden cardiac event (arrest/death), or abnormal investigation results. Data on detailed anatomic features were abstracted from echocardiography, computed tomography, magnetic resonance imaging, operative, and/or surgeon-completed reports.There were 236 patients with negative ischemia test results, and 49 with evidence of ischemia (including 18 who presented with a sudden cardiac event); 275 asymptomatic patients who had not undergone provocative ischemia testing were excluded from primary analyses. Patients with ischemia (vs without), were more likely to have left anomalous coronary arteries (28/49 vs 46/236; P .0001). Of patients with ischemia (vs without), those with anomalous left coronary arteries were more likely to have an intramural coronary artery course, or a high or slit-like coronary artery orifice. Of patients with ischemia (vs without), those with anomalous right coronary arteries were more likely to have a longer intramural course. Among patients with ischemia, the occurrence of sudden cardiac events was not shown to have any associated anatomic features.Anatomic features including coronary artery involved, intramural course and length, and orifice anomalies were associated with evidence of myocardial ischemia for patients with anomalous aortic origin of a coronary artery. These features might importantly inform risk stratification and decisions regarding surgical management.

Summary Quality of life studies must diminish group heterogeneity and ensure that the dataset has a wide range of potential associated factors for optimal evaluation. The factors associated with domain scores found by Pragt et al. point toward the significant group heterogeneity related to diagnosis, age, and valve type and position.

BACKGROUND: Mastering the technical skills required to perform pediatric cardiac valve surgery is challenging in part due to limited opportunity for practice. Transformation of 3D echocardiographic (echo) images of congenitally abnormal heart valves to realistic physical models could allow patient-specific simulation of surgical valve repair. We compared materials, processes, and costs for 3D printing and molding of patient-specific models for visualization and surgical simulation of congenitally abnormal heart valves. METHODS: Pediatric atrioventricular valves (mitral, tricuspid and common atrioventricular valve) were modeled from transthoracic 3D echo images using semi-automated methods implemented as custom modules in 3D Slicer. Valve models were then both 3D printed in soft materials and molded in silicone using 3D printed “negative” molds. Using pre-defined assessment criteria, valve models were evaluated by congenital cardiac surgeons to determine suitability for simulation. RESULTS: Surgeon assessment indicated that the molded valves had superior material properties for the purposes of simulation compared to directly printed valves (p

Little information is available about the transportation costs incurred from the missed prenatal diagnosis of congenital heart disease (CHD). The objectives of the present study were to analyze the costs of emergency transportation related to the postnatal diagnosis of major CHD and to perform a cost/benefit analysis of additional training for ultrasound technicians to study the implications of improved prenatal detection rates. The 1-year costs incurred for emergency transportation of pre- and postnatally diagnosed infants with CHD in Northern California and North Western Nevada were calculated and compared. The prenatal detection rate in our cohort (n = 147) was 30.6%. Infants postnatally diagnosed were 16.5 times more likely (p0.001) to require emergency transport. The associated emergency transportation costs were US$542,143 in total for all patients with CHD. The mean cost per patient was $389.00 versus $5,143.51 for prenatally and postnatally diagnosed infants, respectively (p0.001). Assuming an improvement in detection rates after 1-day training for ultrasound technicians, the investment in training cost can be recouped in 1 year if the detection rate increased by 2.4% to 33%. Savings of $6,543,476 would occur within 5 years if the detection rate increased to 50%. In conclusion, CHD diagnosed postnatally results in greater costs related to emergency transportation of ill infants. Improving the prenatal detection rates through improved ultrasound technician training could result in considerable cost savings.

Objectives We sought to determine cardiac outcomes in young adults with complete transposition of the great arteries (TGA) after the arterial switch operation (ASO). Background Although cardiac outcomes in the pediatric population with TGA after ASO have been well described, outcomes in the adult population have not to our knowledge been studied. Methods We determined late survival in all operative survivors with TGA after ASO performed before 1991 at our local pediatric referring hospital. In the subset of adults (n = 65) followed in our adult congenital cardiac clinic, we examined cardiac outcomes in adulthood. Results Survival of the 132 infants discharged from hospital after ASO was 97% (70% confidence interval [CI]: 95.0% to 98.1%) at 20 years. In the 65 patients (mean age 21 ± 3 years, 62% male) followed at our institution, 17% (11 of 65) had at least 1 clinically significant cardiac lesion, including ventricular dysfunction, valvular dysfunction, or arrhythmias. Residual lesions were more common in those who had had cardiac reinterventions in childhood (odds ratio: 10.7, 95% CI: 2.1 to 55). In adulthood, 5 patients (8%) had arrhythmia requiring treatment and 7 patients (11%) required reinterventions (5 reoperations and 2 pacemaker implantations). Intervention for aortic valve regurgitation and aortic root dilation were not observed. Exercise capacity was reduced in most adults (82%) after ASO. Conclusions Although most adults after ASO are well, and few have residual defects, there are subgroups, particularly those who needed further cardiac intervention in childhood, who are at higher risk for ventricular and valve dysfunction and arrhythmias.

Thrombosis is a major complication of central venous access devices, its incidence depending on material, diameter, tip position, and tip surface. Catheters are usually cut to the appropriate length for accurate positioning. Cutting is not recommended, however, as rough surfaces can serve as a nidus for thrombosis. The present study was performed to assess the roughness of catheter tips provided by various manufacturers versus the roughness once cut and handled. Three types of catheters (Hickman, Port-a-Cath, and Per Q Cath) were cut by scissors, iris scissors, or scalpel, and were handled with debakey forceps, a needle driver, adson with teeth or adson without teeth, to determine the damage created on the catheter. The uncut manufactured tip was compared as a control. Scanning electron microscopy was used for imaging of all samples, and roughness was quantified by atomic force microscopy for the cutting methods. Qualitative results by scanning electron microscopy showed that scalpel-cut and manufactured ends appeared smoother relative to those cut with scissors or iris scissors. This complemented the roughness analysis by atomic force microscopy. Catheters handled by debakey forceps and adsons with teeth showed most roughness, visible as deep holes or a grainy surface when observed by high-magnification scanning electron microscopy. Overall, the smoothest result was produced by scalpel, followed by the manufactured end, scissors, and iris scissors. Handling should be minimized, and use of adsons with teeth, needle drivers and debakey forceps should be avoided, as they can leave permanent damage. Adsons without teeth appeared the least damaging.

Aortocoronary artery bypass grafts are time tested to be effective definitive therapy of symptomatic coronary artery disease since their inception in the 1960s. Over the years, multiple factors have affected the long-term outcome and patency rates of vein grafts. These can be divided into acute, subacute, and delayed categories. The most common causes, respectively, are thrombosis, intimal hyperplasia, and accelerated atherosclerosis. Numerous studies have analyzed postoperative angiographic images to evaluate these phenomena, and medical therapies have been instituted to prevent occlusion of these grafts. Besides these pathologic mechanisms, a surgeon and the surgeon's team must be aware of potential early reversible causes of coronary occlusion that are most often mechanical in nature. Graft kinking and external compression are known adverse events that may require early intervention to correct the underlying cause of graft occlusion. Here we present a case of graft occlusion by what we refer to as TOUGH syndrome: Thoracostomy tube Occluding Underlying coronary Graft causing Harm.

Prosthetic heart valves, both mechanical and biological (xenograft valves, stented or unstented), show an inflammatory reaction (infective endocarditis), associated predominantly with bacterial/fungal infection. Somewhat surprisingly, no immune-mediated reaction has been reported thus far. This may, among other reasons, be related to the fact that the tissues are "fixed" with aldehydes and are virtually isolated from host circulation, separated by synthetic material (the valve stent and the fabric covering it). Stentless valves (especially these without fabric covering them), however, have no such "isolation" from the host circulation. While the Toronto-Stentless Porcine Valve has a covering of fabric, the Medtronic Freestyle valve has no such covering. It is perhaps not so surprising therefore that at the intermediate time point of 5 to 6 years, some valves are beginning to show such an immune reaction.

Background— Definition and management of right dominant unbalanced atrioventricular septal defect (AVSD) remains challenging because unbalance entails a spectrum of left heart hypoplasia. Previous work has highlighted atrioventricular valve (AVV) index as a reasonable defining echocardiographic measure. We sought to assess which additional echocardiographic features might provide further characterization. Methods and Results— From a multi-institutional cohort of complete AVSD, 52 preoperative echocardiograms of patients with presumed right dominant unbalanced AVSD (based on AVV index) and 60 randomly selected preoperative echocardiograms from patients with presumed balanced AVSD were reviewed. Cluster analysis of echocardiographic variables was used to group patients with similar features. Discriminant function analysis was used to explore which variables differentiated these groups. Three groups were identified from the cluster analysis. Echocardiographic variables that differentiated these groups were right ventricle:left ventricle inflow angle, LV width/LV length, left AVV color diameter at smallest inflow, left AVV color diameter at annulus, right AVV overriding left atrium, and LV width. Based on procedures and outcomes, 1 group likely represented balanced patients, whereas 2 groups with similar outcomes likely represented unbalanced patients. The dominant differentiating echocardiographic variable between the 3 cluster groups was the right ventricle:LV inflow angle (partial R 2 =0.86), defined as the angle between the base of the right ventricle and LV free wall, using the crest of the ventricular septum as apex of the angle. Conclusions— The angle of right ventricle/LV inflow and other surrogates of inflow may be important defining echocardiographic measures of right dominant unbalanced AVSD, although confirmation is needed.

Background Size mismatch between body and a systemic-to-pulmonary shunt can result in excessive pulmonary blood flow, compromising systemic oxygen delivery. Previously reported techniques to mechanically restrict shunt flow lack precision and reproducibility. We developed a formula for shunt banding and assessed its efficacy and reproducibility by in vitro and clinical measurements. Methods Formulas to determine diameter reduction, length of banding, and effect on the ratio of pulmonary blood flow (Q p ) to systemic blood flow (Q s ) were established. In vitro measurements of different shunt grafts were performed. Results were compared with calculations and clinical data. Clinical outcome was retrospectively assessed in all patients (n = 8) who underwent a shunt banding procedure at our institution between 2008 and 2012. Results Our formulas can adequately predict the length of the band based on the desired diameter and shunt type or on the Q p :Q s mismatch. In vitro measurements correlated with the manufacturer's specifications in small shunts (≤5 mm diameter; 0.45 mm mean wall thickness). The calculated diameters of these shunts were closely correlated with in vitro measurements ( r = 0.953; P = .001). Arterial saturation, pH, and calculated Q p :Q s decreased significantly with banding ( P = .026, .002, and .004, respectively). Clinical effects varied among patients, with hemodynamically stable patients achieving the most benefit. Adjustment of the band was required in 1 patient. No shunt thrombosis or shunt banding-related complications were noted. Conclusions Our formulas and surgical strategy offer a new approach to controlling excessive pulmonary blood flow in shunt-dependent circulations in an effective and predictable way. The best reproducibility was achieved in small, thin-walled shunts. This strategy was most effective in patients with pulmonary overcirculation without hemodynamic decompensation.

Background The durability of atrioventricular valve (AVV) repair and risk factors for recurrent AVV regurgitation (AVVR) and reintervention in single-ventricle patients are not well defined. Methods Among 66 single-ventricle patients who underwent AVV repair between 1998 and 2011, 58 hospital survivors (88%) were retrospectively reviewed. Freedom from recurrent AVVR and reintervention were analyzed with Kaplan-Meier analysis. Predictors for recurrent AVVR, ventricular dysfunction, and reintervention were analyzed using regression analysis. Results Significant (more than mild+) AVVR developed in 47 patients (81%) during mean follow-up of 37 months (range, 0.2 to 103 months). Freedom from significant AVVR was 23.8% at 1 year and 16.9% at 5 years. Reintervention was performed in 12 patients (26%) at a mean of 24 months (range, 2 to 64 months) after the initial repair. Freedom from reintervention was 92.3% at 1 year and 75.3% at 5 years. There were 11 late deaths (19%). Predictors for recurrent AVVR included repair at stage II ( p = 0.020) and cardiopulmonary bypass time ( p = 0.014). Predictors for reintervention included valvuloplasty as a repair technique ( p = 0.013), cardiopulmonary bypass time ( p = 0.002), aortic cross-clamp time ( p = 0.003), and significant residual intraoperative AVVR ( p = 0.012). Intraoperative ventricular dysfunction ( p p = 0.005), and cleft as the mechanism of regurgitation ( p = 0.023) predicted postrepair ventricular dysfunction. Conclusions Although significant AVVR developed in most patients within 1 year of repair, the need for repeat valve repair is relatively low if ventricular function is preserved. Ventricular function after repair did not predict late survival but was related to the longevity of AVV competence and subsequent risk for reintervention.

The anomalous aortic origin of a coronary artery from the wrong sinus of Valsalva with interarterial, intramural, and/or intraconal course is a rare congenital anomaly that is associated with a high risk of sudden death in children. The Congenital Heart Surgeons’ Society established the Registry of Anomalous Aortic Origin of the Coronary Artery to help determine the outcome of children and young adults managed with surgical intervention versus observation and to test the hypothesis that subsets of patients with anomalous aortic origin of a coronary artery can be identified in whom the risk of intervention is less than the risk of observation. All institutional members of the Congenital Heart Surgeons’ Society were recruited for participation. The registry consists of a retrospective cohort of patients diagnosed between 1 January, 1998 and 20 January, 2009 and a prospective, population-based cohort of patients newly diagnosed from 21 January, 2009 onwards. Baseline demographics, diagnoses, and results of tests will be obtained through a review of the medical records. Annual follow-up data will be collected. Data will be analysed for different factors of risk at diagnosis, different strategies of treatment, and the impact of both on the outcomes of the patients. As of June 2010, 28 institutions had applied for approval from their institutional review board and 16 institutions had received approval from their institutional review board. Seventy-four patients have enrolled to date. We hope to use the established Pediatric Cardiomyopathy Registry as a guide to successful implementation, with a cooperative effort between institutions. The overall purpose of the Registry of Anomalous Aortic Origin of the Coronary Artery is to determine the outcome of surgical intervention versus observation in children and young adults with anomalous aortic origin of a coronary artery, and to describe the natural and “unnatural” history of these patients over the course of their lifetime. In this report, we describe the creation and design of the Registry of Anomalous Aortic Origin of the Coronary Artery. Data from the registry will be published at a later date.