Identifying pediatric heart murmurs and distinguishing innocent from pathologic using deep learning.

OBJECTIVE: To develop a deep learning algorithm to perform multi-class classification of normal pediatric heart sounds, innocent murmurs, and pathologic murmurs. METHODS: We prospectively enrolled children under age 18 being evaluated by the Division of Pediatric Cardiology. Parents provided consent for a deidentified recording of their child's heart sounds with a digital stethoscope. Innocent murmurs were validated by a pediatric cardiologist and pathologic murmurs were validated by echocardiogram. To augment our collection of normal heart sounds, we utilized a public database of pediatric heart sound recordings (Oliveira, 2022). We propose two novel approaches for this audio classification task. We train a vision transformer on either Markov transition field or Gramian angular field image representations of the frequency spectrum. We benchmark our results against a ResNet-50 CNN trained on spectrogram images. RESULTS: Our final dataset consisted of 366 normal heart sounds, 175 innocent murmurs, and 216 pathologic murmurs. Innocent murmurs collected include Still's murmur, venous hum, and flow murmurs. Pathologic murmurs included ventricular septal defect, tetralogy of Fallot, aortic regurgitation, aortic stenosis, pulmonary stenosis, mitral regurgitation and stenosis, and tricuspid regurgitation. We find that the Vision Transformer consistently outperforms the ResNet-50 on all three image representations, and that the Gramian angular field is the superior image representation for pediatric heart sounds. We calculated a one-vs-rest multi-class ROC curve for each of the three classes. Our best model achieves an area under the curve (AUC) value of 0.92 ± 0.05, 0.83 ± 0.04, and 0.88 ± 0.04 for identifying normal heart sounds, innocent murmurs, and pathologic murmurs, respectively. CONCLUSION: We present two novel methods for pediatric heart sound classification, which outperforms the current standard of using a convolutional neural network trained on spectrogram images. To our knowledge, we are the first to demonstrate multi-class classification of pediatric murmurs. Multiclass output affords a more explainable and interpretable model, which can facilitate further model improvement in the downstream model development cycle and enhance clinician trust and therefore adoption.

Annexin A2 Loss After Cardiopulmonary Bypass and Development of Acute Postoperative Respiratory Dysfunction in Children.

The primary objective of this study was to determine whether expression of the multifunctional and adherens junction-regulating protein, annexin A2 (A2), is altered following cardiopulmonary bypass (CPB). A secondary objective was to determine whether depletion of A2 is associated with post-CPB organ dysfunction in children. DESIGN: In a prospective, observational study conducted over a 1-year period in children undergoing cardiac surgery requiring CPB, we analyzed A2 expression in peripheral blood mononuclear cells at different time points. We then assessed the relationship of A2 expression with organ function at each time point in the early postoperative period. SETTING: Twenty-three-bed mixed PICU in a tertiary academic center. PARTICIPANTS: Patients 1 month to 18 years old undergoing cardiac surgery requiring CPB. MEAN OUTCOME MEASUREMENTS AND RESULTS: We analyzed A2 expression in 22 enrolled subjects (n = 9, 1-23 mo old; n = 13, 2-18 yr old) and found a proteolysis-mediated decline in intact A2 immediately after bypass (p = 0.0009), reaching a median of 4% of baseline at 6 hours after bypass (p < 0.0001), and recovery by postoperative day 1. The degree of A2 depletion immediately after bypass in 1-23-month-olds correlated strongly with the extent of organ dysfunction, as measured by PICU admission Vasoactive-Ventilation-Renal (p = 0.004) and PEdiatric Logistic Organ Dysfunction-2 (p = 0.039) scores on postoperative day 1. A2 depletion immediately after bypass also correlated with more protracted requirement for both respiratory support (p = 0.007) and invasive ventilation (p = 0.013) in the 1-23-month-olds. CONCLUSIONS AND RELEVANCE: The degree of depletion of A2 following CPB correlates with more severe organ dysfunction, especially acute respiratory compromise in children under 2 years. These findings suggest that loss of A2 may contribute to pulmonary microvascular leak in young children following CPB.

Epidemiology of severe bleeding in children following cardiac surgery involving cardiopulmonary bypass: use of Bleeding Assessment Scale for critically Ill Children (BASIC).

OBJECTIVES: To describe the epidemiology of severe bleeding in the immediate post-operative period in children who undergo cardiopulmonary bypass surgery using the Bleeding Assessment Scale for critically Ill Children (BASIC). STUDY DESIGN: Retrospective cohort study in a paediatric ICU from 2015 to 2020. RESULTS: 356 children were enrolled; 59% were male with median (IQR) age 2.1 (0.5-8) years. Fifty-seven patients (16%) had severe bleeding in the first 24 hours post-operatively. Severe bleeding was observed more frequently in younger and smaller children with longer bypass and cross-clamp times (p-values <0.001), in addition to higher surgical complexity (p = 0.048). Those with severe bleeding received significantly more red blood cells, platelets, plasma, and cryoprecipitate in the paediatric ICU following surgery (all p-values <0.001). No laboratory values obtained on paediatric ICU admission were able to predict severe post-operative bleeding. Those with severe bleeding had significantly less paediatric ICU-free days (p = 0.010) and mechanical ventilation-free days (p = 0.013) as compared to those without severe bleeding. CONCLUSIONS: Applying the BASIC definition to our cohort, severe bleeding occurred in 16% of children in the first day following cardiopulmonary bypass. Severe bleeding was associated with worse clinical outcomes. Standard laboratory assays do not predict bleeding warranting further study of available laboratory tests.

Chylous pericardial effusion with cardiac tamponade in a child treated with imatinib.

Chylous pericardial effusions are extremely rare outside of thoracic and cardiac surgery patients. We report the case of an 8-year-old girl with history of recurrent benign giant cell granulomas who developed a large chylous pericardial effusion with cardiac tamponade soon after beginning therapy with imatinib. In this article, we discuss the presentation, diagnosis, and management and review the published literature of this rarely reported side effect of this medication.

Hemostatic efficacy of pathogen-reduced platelets in children undergoing cardiopulmonary bypass.

BACKGROUND: Pediatric patients undergoing cardiopulmonary bypass (CPB) often require blood component transfusions. Pathogen-reduction (PR) of platelets reduces the risk of microbial contamination; however, its effect on hemostatic efficacy in this population is unclear. This study sought to characterize the hemostatic efficacy of PR platelets in children undergoing CPB. STUDY DESIGN AND METHODS: We performed a retrospective chart review of patients admitted to a pediatric intensive care unit following CPB surgery from 2015 to 2019. Demographic data, validated scoring of repair complexity, products received, and outcomes were compared. The primary outcome was postoperative chest tube bleeding. RESULTS: A total of 140 patients were enrolled. The majority of surgeries (124/140) were Risk Adjustment for Congenital Heart Surgery (RACHS) 1-3 repairs. Seventy-four percent of patients (104/140) received only standard platelets whereas 26% (36/140) received PR platelets. There were no differences between the groups in the age (p = .90), sex (p = .20) or RACHS score (p = .06). Postoperatively, there was no difference in the median chest tube output for 1 h (p = .27), 2 h (p = .26), 4 h (p = .09), 8 h (p = .16), or for the first 24 h following surgery (p = .23) in patients who received standard versus PR platelets. There was also no difference in receipt of platelets (p = .18), cell saver (p = .79), or cryoprecipitate (p = .28). CONCLUSION: Patients receiving PR platelets did not have more blood loss or require more transfusions than those who received standard platelets. This suggests that PR platelets may provide acceptable hemostasis with the additional benefits of reduced risk of microbial contamination in pediatric patients undergoing CPB.

Pulmonary artery thromboembolism in a critically ill neonate successfully treated using thrombolytic therapy.

Pulmonary artery thromboembolism is a common and treatable cause of adult pulmonary hypertension. Although rare in children, if undiagnosed, it can result in significant morbidity and mortality. We report a case of a cyanotic neonate found to have bilateral pulmonary arterial thrombi who successfully underwent thrombolysis using tissue plasminogen activator with prompt resolution of right ventricular hypertension.

The Deconditioning Effect of the COVID-19 Pandemic on Unaffected Healthy Children.

The COVID-19 pandemic has had devastating direct consequences on the health of affected patients. It has also had a significant impact on the ability of unaffected children to be physically active. We evaluated the effect of deconditioning from social distancing and school shutdowns implemented during the COVID-19 pandemic on the cardiovascular fitness of healthy unaffected children. This is a single-center, retrospective case-control study performed in an urban tertiary referral center. A cohort of 10 healthy children that underwent cardiopulmonary exercise testing after COVID-19 hospital restrictions were lifted was compared to a matched cohort before COVID-19-related shutdowns on school and after-school activities. Comparisons of oxygen uptake (VO2) max and VO2 at anaerobic threshold between the pre- and post-COVID-19 cohorts were done. The VO2 max in the post-COVID cohort was significantly lower than in the pre-COVID cohort (39.1 vs. 44.7, p = 0.031). Only one out of ten patients had a higher VO2 max when compared to their matched pre-COVID control and was also the only patient with a documented history of participation in varsity-type athletics. The percentile of predicted VO2 was significantly lower in the post-COVID cohort (95% vs. 105%, p = 0.042). This study for the first time documented a significant measurable decline in physical fitness of healthy children as a result of the COVID-19 pandemic and its associated restrictions. Measures need to be identified that encourage and facilitate regular exercise in children in a way that are not solely dependent on school and organized after-school activities.

The Use of Hemostatic Blood Products in Children Following Cardiopulmonary Bypass and Associated Outcomes.

To describe the use of hemostatic transfusions in children following cardiac surgery with cardiopulmonary bypass and the association of hemostatic transfusions postoperatively with clinical outcomes. DESIGN: A retrospective cohort study. SETTING: PICU of a tertiary care center from 2011 to 2017. PATIENTS: Children 0-18 years old undergoing cardiac surgery with cardiopulmonary bypass. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Four-hundred twenty children underwent cardiac surgery with cardiopulmonary bypass. The median (interquartile range) age was 0.8 years (0.3-5 yr) and 243 (58%) were male. The majority of cases were classified as Risk Adjustment for Congenital Heart Surgery 2 (223, 54%) or Risk Adjustment for Congenital Heart Surgery 3 (124, 30%). Twenty-four percent of children (102/420) received at least one hemostatic transfusion with the most common first product being platelet transfusions (47/102), followed by plasma (44/102), and cryoprecipitate (11/102). The children who received hemostatic transfusions were younger (p = 0.006), had lower body weights (p = 0.004), less likely to be their initial operation with cardiopulmonary bypass (p = 0.003), underwent more complex surgeries (p = 0.001) with longer bypass runs (p < 0.001), and had more use of hypothermic circulatory arrest (p = 0.014). The receipt of hemostatic blood products postoperatively was independently associated with more days of mechanical ventilation (p < 0.001) and longer PICU lengths of stay (p = 0.001) but not with time receiving vasoactive mediations (p = 0.113) or nosocomial infections (p = 0.299). CONCLUSIONS: Nearly one-quarter of children undergoing cardiac repair with cardiopulmonary bypass receive hemostatic transfusions postoperatively. These blood products are independently associated with worse clinical outcomes. Larger studies should be performed to determine the hemostatic efficacy of these products, as well as to clarify associated morbidities, in order to inform proper blood management.

Registries, Risk Calculators, and Risk-Adjusted Outcomes: Current Usage, Limitations, and Future Prospects.

Small study sizes are a limiting factor in assessing outcome measures in pediatric cardiology. It is even more difficult to assess the outcomes of congenital catheterizations where the sample sizes are even smaller, particularly on a individual institutional level. The creation of multicenter registries is a method by which investigators can pool data to better assess quality and outcome measures of these procedures. No registry is perfect with several being available today, each with its own strengths and weaknesses. In addition, there are a multitude of methods currently used to assess quality and outcomes from the data contained in these registries, each having its own limitations as well. Nonetheless, multicenter registrities remain one of the best available options to improve the quality of care for pediatric interventional cardiac catheterization. Below, we provide an overview of the current state of quality assessment/improvement in pediatric interventional cardiology including a review of the available registrities and the metrics used to measure quality of care and outcomes.

QT Interval Prolongation in the Pediatric Oncologic Population on Methadone.

Studies have been conducted on adults prescribed with methadone to determine the necessary frequency of QTc monitoring but no consensus has been reached and no similar research has been conducted in the pediatric population. The objective of this retrospective study was to determine the occurrence rate of QTc interval prolongation associated with methadone use in a pediatric oncologic population. In total, 18% of patients developed QTc interval prolongation. These patients had longer baseline QTc intervals and were on more QTc interval-prolonging medications. Our data suggest that these variables may be able to risk stratify patients who require more frequent monitoring.

Complete atrioventricular canal repair with a decellularized porcine small intestinal submucosa patch.

BACKGROUND: Congenital heart defects affect nearly 1% of all children born per year in the United States, and complete atrioventricular canal (CAVC) accounts for 2%-9%. While several patch materials have been used for septal defect closure during CAVC repair, clear superiority of one material over another has yet to be established. METHODS: A retrospective review of clinical outcomes following CAVC repair at Morgan Stanley Children's Hospital/Columbia University was performed on operations conducted from March 2010 to September 2017. Univariate and Kaplan-Meir survival analyses were utilized to evaluate primary outcomes of interest following CAVC repair in the modern surgical era. RESULTS: A total of 73 patients were analyzed, with an average operative age of 22 weeks. The majority (71%) of the patients underwent a 2-patch repair. A CorMatrix patch was used for ventricular septal defect(VSD) closure in 77% of the patients, and/or in 75% of atrial septal defect closures. There was one in-hospital mortality (1.4%) due to respiratory failure. One patient required a pacemaker. At mid-term follow-up (1.6 years), a total of 7 patients required 8 reoperations due to cardiac-related indications, including 5 for left atrioventricular valve (LAVV) repair, 1 for LAVV replacement, and 2 isolated residual VSDs. CONCLUSION: A standardized repair for CAVC results in excellent outcomes in the current era, with low rates of reoperations. CorMatrix for the closure of CAVC has proven to produce good results with equivalent outcomes to other patch materials. Its ease of use and pliability make it an attractive alternative for consideration.

Patients with anomalous aortic origin of the coronary artery remain at risk after surgical repair.

OBJECTIVES: Anomalous aortic origin of a coronary artery (AAOCA) from the opposite sinus of Valsalva is a rare cardiac anomaly associated with sudden cardiac death (SCD). Single-center studies describe surgical repair as safe, although medium- and long-term effects on symptoms and risk of SCD remain unknown. We sought to describe outcomes of surgical repair of AAOCA. METHODS: We reviewed institutional records for patients who underwent AAOCA repair, from 2001 to 2016, at 2 affiliated institutions. Patients with associated heart disease were excluded. RESULTS: In total, 60 patients underwent AAOCA repair. Half of the patients (n = 30) had an anomalous left coronary artery arising from the right sinus of Valsalva and half had an anomalous right. Median age at surgery was 15.4 years (interquartile range, 11.9-17.9 years; range, 4 months to 68 years). The most common presenting symptoms were chest pain (n = 38; 63%) and shortness of breath (n = 17; 28%); aborted SCD was the presenting symptom in 4 patients (7%). Follow-up data were available for 54 patients (90%) over a median of 1.6 years. Of 53 patients with symptoms at presentation, 34 (64%) had complete resolution postoperatively. Postoperative mild or greater aortic insufficiency was present in 8 patients (17%) and moderate supravalvar aortic stenosis in 1 (2%). One patient required aortic valve replacement for aortic insufficiency. Two patients required reoperation for coronary stenosis at 3 months and 6 years postoperatively. CONCLUSIONS: Surgical repair of AAOCA is generally safe and adverse events are rare. Restenosis, and even sudden cardiac events, can occur and long-term surveillance is critical. Multi-institutional collaboration is vital to identify at-risk subpopulations and refine current recommendations for long-term management.

Effectiveness of echocardiography simulation training for paediatric cardiology fellows in CHD.

Simulation is used in many aspects of medical training but less so for echocardiography instruction in paediatric cardiology. We report our experience with the introduction of simulator-based echocardiography training at Weill Cornell Medicine for paediatric cardiology fellows of the New York-Presbyterian Hospital of Columbia University and Weill Cornell Medicine. Knowledge of CHD and echocardiographic performance improved following simulation-based training. Simulator training in echocardiography can be an effective addition to standard training for paediatric cardiology trainees.

Cardiac Function After Tetralogy of Fallot/Complete Atrioventricular Canal Repair.

BACKGROUND: Repair of complete atrioventricular canal (CAVC) with tetralogy of Fallot (TOF) is a challenging operation increasingly being performed as a complete, primary repair in infancy. Previous studies have focused on perioperative outcomes; however, midterm valve function, ventricular function, and residual obstruction have received little attention. METHODS: We retrospectively reviewed 20 patients who underwent CAVC/TOF repair (January 2005 to December 2014). A two-patch repair was used in all patients to correct the CAVC defect. Tetralogy of Fallot repair included transannular patch in 11 (65%) patients and valve-sparing in 6 (35%) patients. RESULTS: The average age at surgery was 72 ± 122 weeks, 40% were male, and 80% had trisomy 21. Mean echo follow-up was 3.0 ± 3.0 years. There were no in-hospital or late mortalities. The rate of reoperation was 20%. At the latest follow-up, moderate left atrioventricular valve regurgitation was present in three (15%) patients and mild stenosis present in seven (35%) patients. One (5%) patient had moderate right ventricular outflow tract (RVOT) obstruction. The valve-sparing population was smaller at the time of surgery than the non-valve-sparing cohort (body surface area: 0.28 ± 0.04 vs 0.42 ± 0.11, P = .002) and less likely to have had a previous shunt (0% vs 64%, P = .01). Among the valve-sparing patients (six), at the latest follow-up, moderate pulmonary insufficiency was present in two (33%) patients. CONCLUSION: Repair of CAVC concomitant with TOF can be performed with low mortality and acceptable perioperative morbidity. Management of the RVOT remains a challenge for the long term.

Takayasu arteritis presenting in the context of active tuberculosis: a pediatric case.

Takayasu arteritis (TA) is a large-vessel vasculitis, most commonly presenting in young adults and more rarely in pediatric patients. An apparent association between TA and Mycobacterium tuberculosis has been noted previously, although this potential relationship is not yet understood. We present the case of a 16-year-old Haitian girl diagnosed with TA, originally presenting in the context of active tuberculosis. Our patient has been treated with antituberculosis therapy, corticosteroids, methotrexate, and rituximab to control her continued active vasculitis. With this case report, we seek to promote further exploration of the apparent association between TA and tuberculosis, as further clarification of the nature of this relationship may lead to the development of more targeted therapies and better outcomes for TA patients.

Role of immunosuppression regimen in post-transplant lymphoproliferative disorder in pediatric heart transplant patients.

BACKGROUND: Post-transplant lymphoproliferative disorder (PTLD) contributes to morbidity and mortality after transplantation. We examined the effect of immunosuppressive regimen on the risk of developing PTLD after pediatric heart transplantation. METHODS: The 324 pediatric heart transplant patients at 2 children's hospitals were retrospectively reviewed for the primary outcome of PTLD development. Patient demographics, rejection frequency, serum cyclosporine and tacrolimus levels, induction therapy, donor and recipient Epstein-Barr virus, and cytomegalovirus serologic status were reviewed and comparisons made between immunosuppressive regimens. Comparisons were also made between transplantation in the early (1984-1995) and late (1996-2008) eras to help account for changes in clinical protocols that occurred during the study period. RESULTS: PTLD developed in 33 (10%), of whom 109 (34%) were treated with tacrolimus. PTLD developed in 15% of those treated with tacrolimus compared with 8% of patients treated solely with cyclosporine. Tacrolimus use was a significant predictor of PTLD, with a hazard ratio [HR] of 4.04 (95% confidence interval [CI], 2.03-8.02; p = 0.0001). Neither Epstein-Barr virus, cytomegalovirus donor/recipient status, nor gender predicted PTLD development. Younger age at transplant, higher rejection frequency, and induction therapy predicted PTLD development by univariate analysis. Multivariate modeling demonstrated that tacrolimus use (HR, 7.03; 95% CI, 2.87-17.2; p < 0.001) remained an independent predictor of PTLD, when controlling for age, era of transplantation, induction therapy, and rejection frequency. CONCLUSIONS: This study suggests the use of tacrolimus after pediatric heart transplantation is independently associated with an increased risk of PTLD compared with cyclosporine alone.

Cost-effectiveness of pediatric heart transplantation.

BACKGROUND: Survival after pediatric heart transplantation has continued to improve. Nonetheless, graft survival is generally <15 years and the costs of transplantation and subsequent immunosuppression are substantial. In the present study, we sought to examine the cost-effectiveness of pediatric heart transplantation. METHODS: Data from 95 pediatric subjects undergoing transplantation at our institution from 1997 through 2004 were reviewed to determine the costs of pediatric heart transplantation. Costs included pre-transplant care, organ procurement, initial hospitalization and follow-up care. Life expectancy was derived from the United Network of Organ Sharing data set. Data were reported as cost per quality-adjusted life-years (QALYs) gained, which were discounted at 3%. Cost-effectiveness was stratified by primary transplantation vs re-transplantation. RESULTS: The mean cost of initial hospitalization and organ procurement was $221,897 per patient for primary transplant and $285,296 per patient for re-transplant. Annual follow-up costs were estimated to be $18,141 in the first year (excluding the first 90 days post-transplant) and $18,480 per year thereafter. Under base-case assumptions, costs per QALY gained were $49,679 for primary transplantation and $87,883 for re-transplantation. Sensitivity analysis yielded a cost-utility range of $44,943 to $57,628 per QALY gained for primary transplantation and $70,834 to $103,661 per QALY gained for re-transplantation. CONCLUSIONS: Costs of primary pediatric heart transplantation are within the accepted range of cost effectiveness. Pediatric heart re-transplantation has higher costs relative to benefits gained owing to shorter graft survival.