A comprehensive study on machine learning models combining with oversampling for bronchopulmonary dysplasia-associated pulmonary hypertension in very preterm infants.

BACKGROUND: Bronchopulmonary dysplasia-associated pulmonary hypertension (BPD-PH) remains a devastating clinical complication seriously affecting the therapeutic outcome of preterm infants. Hence, early prevention and timely diagnosis prior to pathological change is the key to reducing morbidity and improving prognosis. Our primary objective is to utilize machine learning techniques to build predictive models that could accurately identify BPD infants at risk of developing PH. METHODS: The data utilized in this study were collected from neonatology departments of four tertiary-level hospitals in China. To address the issue of imbalanced data, oversampling algorithms synthetic minority over-sampling technique (SMOTE) was applied to improve the model. RESULTS: Seven hundred sixty one clinical records were collected in our study. Following data pre-processing and feature selection, 5 of the 46 features were used to build models, including duration of invasive respiratory support (day), the severity of BPD, ventilator-associated pneumonia, pulmonary hemorrhage, and early-onset PH. Four machine learning models were applied to predictive learning, and after comprehensive selection a model was ultimately selected. The model achieved 93.8% sensitivity, 85.0% accuracy, and 0.933 AUC. A score of the logistic regression formula greater than 0 was identified as a warning sign of BPD-PH. CONCLUSIONS: We comprehensively compared different machine learning models and ultimately obtained a good prognosis model which was sufficient to support pediatric clinicians to make early diagnosis and formulate a better treatment plan for pediatric patients with BPD-PH.

Echocardiographic markers at diagnosis of persistent pulmonary hypertension of the newborn.

OBJECTIVES: Clinical parameters along with echocardiographic markers are used to interrogate the haemodynamics in persistent pulmonary hypertension of the newborn (PPHN). The aim of this study was to compare different echocardiographic markers in recent cohort of newborn infants with and without PPHN. METHODS: In this retrospective study, common echocardiographic markers were examined in infants>34 weeks' gestation with PPHN (cases) and without PPHN (controls). Infants with congenital heart disease were excluded. Binary regression testing was used to evaluate echocardiographic markers predicting PPHN and death. In addition, diagnostic accuracy testing of echocardiographic markers using ROC was also performed. Intra-observer reliability for echocardiographic markers was examined using coefficient of variation (CoV) and intraclass correlation. RESULTS: Fifty-two infants were studied; 22 (42 %) infants with PPHN had significantly higher oxygen requirement, oxygenation index and ventilation days when compared with controls. Echocardiographic markers such as TR Vmax, S/D TR, PAAT, TAPSE and eccentricity index (EI) were significantly different between cases and controls. Receiver operator characteristics analysis of echocardiographic markers revealed TR Vmax 0.96 (0.9-1.0), S/D TR 0.95 (0.87-1.0) and end systolic EI 0.94 (0.87-1.0). These markers were found to predict death in this cohort of infants. CoV and Intra-observer reliability was good for various echocardiographic markers. CONCLUSIONS: Among the various echocardiographic markers studied, TR Vmax when present along with S/D TR and end systolic EI had good intra-observer reliability and were diagnostic of PPHN and predicted death in this cohort. Future trials could use these markers in studies examining PPHN.

Impaired Myocardial Work in Children with Hypertrophic Cardiomyopathy and Left Ventricular Fibrosis on Cardiac Magnetic Resonance Imaging.

Echocardiography is pivotal for diagnosis and monitoring of hypertrophic cardiomyopathy (HCM) and can evaluate myocardial function using myocardial work (MW) calculations. Echocardiography is often supplemented by cardiovascular magnetic resonance (CMR) imaging, which can detect myocardial fibrosis using late gadolinium enhancement (LGE). We sought to study the relationship between baseline LGE and MW at baseline and during follow-up in pediatric HCM patients. During the study period (2008-2023), 75 patients were followed up for HCM. In 14 patients (age 14.2 ± 2.8 years, 50.0% male, 6.4 ± 2.9 years follow-up), both LGE-CMR and echocardiography were performed. Global work index (GWI), global constructive work (GCW), global wasted work, and global work efficiency (GWE) were measured, and myocardial fibrosis was estimated by qualitative assessment of LGE. Patients with LGE (n = 7) exhibited significantly impaired baseline MW, including GWI (mean difference, MD - 487.4 mmHg %, 95% CI [- 866.8 mmHg % to - 108.3 mmHg %], p = 0.027), GCW (MD - 536.8 mmHg %, 95% CI [- 929.8 mmHg % to - 144.4 mmHg %], p = 0.020), and GWE (MD - 4.4%, 95% CI [- 8.1% to - 0.7%], p = 0.039). Regional analysis revealed impaired MW indices in segments with LGE, notably basal and mid septal segments. GWI demonstrated high diagnostic performance for LGE presence (sensitivity 93%, specificity 88%, and area under receiver operating characteristic curve 0.85). Baseline LGE presence had no significant impact on MW deterioration during follow-up. MW is significantly impaired in HCM patients with myocardial fibrosis, highlighting potential utility of echocardiography-derived MW analysis as a valuable tool.

pECGreview: Assessment of a Novel Tool to Evaluate the Accuracy of Pediatric ECG Interpretation Skills.

The skill of interpretation of the electrocardiogram (ECG) remains poor despite existing educational initiatives. We sought to evaluate the validity of using a subjective scoring system to assess the accuracy of ECG interpretations submitted by pediatric cardiology fellows, trainees, and faculty to the Pediatric ECG Review (pECGreview), a web-based ECG interpretation training program. We conducted a retrospective, cross-sectional study of responses submitted to pECGreview. ECG interpretations were assessed independently by four individuals with a range of experience. Accuracy was assessed using a 3-point scale: 100% for generally correct interpretations, 50% for over- or underdiagnosis of minor ECG abnormalities, and 0% for over- or underdiagnosis of major ECG abnormalities. Inter-rater agreement was assessed using expanded Bland-Altman plots, Pearson correlation coefficients, and Intraclass Correlation Coefficients (ICC). 1460 ECG interpretations by 192 participants were analyzed. 107 participants interpreted at least five ECGs. The mean accuracy score was 76.6 ± 13.7%. Participants were correct in 66.1 ± 5.1%, had minor over- or underdiagnosis in 21.5 ± 4.6% and major over- or underdiagnosis in 12.3 ± 3.9% of interpretations. Validation of agreement between evaluators demonstrated limits of agreement of 11.3%. Inter-rater agreement exhibited consistent patterns (all correlations ≥ 0.75). Absolute agreement was 0.74 (95% CI 0.69-0.80), and average measures agreement was 0.92 (95% CI 0.89-0.94). Accuracy score analysis of as few as five ECG interpretations submitted to pECGreview yielded good inter-rater reliability for assessing and ranking ECG interpretation skills in pediatric cardiology fellows in training.

End-stage heart failure in congenitally corrected transposition of the great arteries: a multicentre study.

BACKGROUND AND AIMS: For patients with congenitally corrected transposition of the great arteries (ccTGA), factors associated with progression to end-stage congestive heart failure (CHF) remain largely unclear. METHODS: This multicentre, retrospective cohort study included adults with ccTGA seen at a congenital heart disease centre. Clinical data from initial and most recent visits were obtained. The composite primary outcome was mechanical circulatory support, heart transplantation, or death. RESULTS: From 558 patients (48% female, age at first visit 36 ± 14.2 years, median follow-up 8.7 years), the event rate of the primary outcome was 15.4 per 1000 person-years (11 mechanical circulatory support implantations, 12 transplantations, and 52 deaths). Patients experiencing the primary outcome were older and more likely to have a history of atrial arrhythmia. The primary outcome was highest in those with both moderate/severe right ventricular (RV) dysfunction and tricuspid regurgitation (n = 110, 31 events) and uncommon in those with mild/less RV dysfunction and tricuspid regurgitation (n = 181, 13 events, P < .001). Outcomes were not different based on anatomic complexity and history of tricuspid valve surgery or of subpulmonic obstruction. New CHF admission or ventricular arrhythmia was associated with the primary outcome. Individuals who underwent childhood surgery had more adverse outcomes than age- and sex-matched controls. Multivariable Cox regression analysis identified older age, prior CHF admission, and severe RV dysfunction as independent predictors for the primary outcome. CONCLUSIONS: Patients with ccTGA have variable deterioration to end-stage heart failure or death over time, commonly between their fifth and sixth decades. Predictors include arrhythmic and CHF events and severe RV dysfunction but not anatomy or need for tricuspid valve surgery.

Multiple recurrent supraventricular tachycardia in infantile tuberous sclerosis complex: management requiring triple-drug therapy.

We report the case of a female neonate admitted to the neonatal ICU with a rapid, narrow-complex tachyarrhythmia determined to be supraventricular tachycardia. Multimodality imaging and genetic testing confirmed a diagnosis of tuberous sclerosis complex with multiple cardiac rhabdomyomas. At 13 days of age, the patient was readmitted, exhibiting recurrent supraventricular tachycardia non-responsive to first-line treatment. Management required triple-drug therapy, whereafter the patient remained stable without recurrences. This is a rare report of supraventricular tachycardia in a functionally normal heart with the occurrence of supraventricular tachycardia due to structural abnormalities, with the possibility of multiple concealed accessory pathways.

Long-Term Consequences of Acute Kidney Injury After Pediatric Cardiac Surgery: A Systematic Review.

OBJECTIVE: The objective of this study was to evaluate the available data on long-term kidney dysfunction, hypertension, and mortality after cardiac surgery-associated acute kidney injury (AKI) in the pediatric population. STUDY DESIGN: PubMed/MEDLINE, Embase, Scopus, and reference lists of relevant articles were searched for eligible studies published from inception through March 2022. Long-term outcomes after pediatric cardiac surgery complicated by AKI and those without were investigated. RESULTS: We identified 14 studies published between 2013 and 2022 that included a total of 6701 patients (AKI: 1376 patients; no AKI: 5325 patients). These studies used different well-established classifications to define AKI. All the studies suggested that AKI after heart surgery is common in the pediatric patient population and reported a potential link between cardiac surgery-associated AKI and important clinical outcomes. However, only 4 out of 11 studies found a strong association between (absence of recovery from) cardiac surgery-associated AKI and risk of developing chronic kidney disease, and 3 out of 5 studies found a significant increase in mortality rates for pediatric patients who developed AKI after cardiac surgery. Only 1 out of 4 studies found an association between AKI and hypertension at 12 months postoperatively, but found no association at later follow-up times. CONCLUSIONS: Although there is a trend, evidence on the long-term consequences of cardiac surgery-associated AKI in the pediatric population is mixed. Genetic syndromes, preexisting kidney disease, univentricular or cyanotic heart conditions, and/or high-complexity surgery may be more important for the development of kidney dysfunction by adolescence and early adulthood. Regardless, these children may benefit from a long-term kidney follow-up.

Preterm Birth Is Associated With Adverse Cardiac Remodeling and Worse Outcomes in Patients With a Functional Single Right Ventricle.

OBJECTIVE: To assess the effects of preterm birth on cardiac structure and function and transplant-free survival in patients with hypoplastic left heart syndrome and associated anomalies throughout the staged palliation process. STUDY DESIGN: Data from the Single Ventricle Reconstruction trial were used to assess the impact of prematurity on echocardiographic measures at birth, Norwood, Stage II, and 14 months in 549 patients with a single functional right ventricle. Medical history was recorded once a year using medical records or telephone interviews. Cox regression models were applied to analyze transplant-free survival to age 6 years. Causal mediation analysis was performed to estimate the mediating effect of birth weight within this relationship. RESULTS: Of the 549 participants, 64 (11.7%) were born preterm. Preterm-born participants had lower indexed right ventricle end-diastolic volumes at birth but higher volumes than term-born participants by age 14 months. Preterm-born participants had an increased risk of death or heart transplantation from birth to age 6 years, with an almost linear increase in the observed risk as gestational age decreased below 37 weeks. Of the total effect of preterm birth on transplant-free survival, 27.3% (95% CI 2.5-59.0%) was mediated through birth weight. CONCLUSIONS: Preterm birth is associated with adverse right ventricle remodeling and worse transplant-free survival throughout the palliation process, in part independently of low birth weight. Further investigation into this vulnerable group may allow development of strategies that mitigate the impact of prematurity on outcomes in patients with hypoplastic left heart syndrome.

Echocardiographic scores for biventricular repair risk prediction of congenital heart disease with borderline left ventricle: a review.

The aim of this review is to highlight the strengths and limitations of major echocardiographic biventricular repair (BVR) prediction models for borderline left ventricle (LV) in complex congenital heart disease (CHD). A systematic search in the National Library of Medicine for Medical Subject Headings and free text terms including echocardiography, CHD, and scores, was performed. The search was refined by adding keywords for critical aortic stenosis (AS), borderline LV, complex left ventricular outflow tract (LVOT) obstruction, hypoplastic left heart syndrome/complex (HLHS/HLHC), and unbalanced atrio-ventricular septal defects (uAVSD). Fifteen studies were selected for the final analysis. We outlined what echocardiographic scores for different types of complex CHD with diminutive LV are available. Scores for CHD with LVOT obstruction including critical AS, HLHS/HLHC, and aortic arch hypoplasia have been validated and implemented by several studies. Scores for uAVSD with right ventricle (RV) dominance have also been established and implemented, the first being the atrioventricular valve index (AVVI). In addition to AVII, both LV/RV inflow angle and LV inflow index have all been validated for the prediction of BVR. We conclude with a discussion of limitations in the development and validation of each of these scores, including retrospective design during score development, heterogeneity in echocardiographic parameters evaluated, variability in the definition of outcomes, differences in adopted surgical and Interventional strategies, and institutional differences. Furthermore, scores developed in the past two decades may have little clinical relevance now. In summary, we provide a review of echocardiographic scores for BVR in complex CHD with a diminutive LV that may serve as a guide for use in modern clinical practice.

Impaired myocardial deformation persists at 2 years in offspring of mothers with diabetes mellitus.

BACKGROUND: A diabetic intrauterine environment has been proposed as a potential etiological mechanism for in utero programming of cardiac disease, and is associated with impaired fetal cardiac function. We aimed to assess cardiac function in offspring of mothers with diabetes mellitus (ODM) and determine whether fetal cardiac abnormalities persist during follow-up. METHODS: Longitudinal observational study to evaluate and compare myocardial function in 40 ODM to age-matched control offspring (CO). Myocardial deformation was measured using speckle-tracking echocardiography (STE). RESULTS: Significant differences were detected in global longitudinal strain (-20.9 ± 3.1 vs. -23.6 ± 2.2%; p = 0.001), global circumferential strain (-24.4 ± 3.9 vs. -26.9 ± 2.7%; p = 0.017), average radial strain (29.0 ± 9.8 vs. 37.1 ± 7.2%; p = 0.003), average longitudinal systolic strain rate (-1.24 ± 0.25/s vs. -1.47 ± 0.30/s; p = 0.011) and average circumferential systolic strain rate (-1.56 ± 0.37/s vs. -1.84 ± 0.37/s; p = 0.013) in comparison to CO up to 2 years of follow-up. Minimal differences were observed within ODM over the 2-year period. CONCLUSION: Impaired cardiac function in ODM persists during 2 years follow-up. Functional cardiac assessment might therefore be useful to detect these unfavorable changes, independent of screening for congenital heart disease or hypertrophic cardiomyopathy in this population. IMPACT: We demonstrate persistence of subclinical myocardial deformation abnormalities in offspring of mothers with diabetes mellitus from fetal life to early childhood years. These results extend the cellular observations in basic and translational research of developmental programming into the clinical realm. Persistence of subclinical myocardial deformation abnormalities may shed light on the known incidence of early cardiovascular disease in offspring of mother with diabetes. Cardiac myocardial strain assessment can be useful to detect these abnormalities, independent of screening for congenital heart disease or hypertrophic cardiomyopathy in this population.

Cardiovascular toxicities with pediatric tyrosine kinase inhibitor therapy: An analysis of adverse events reported to the Food and Drug Administration.

We sought to examine cardiovascular toxicities associated with tyrosine kinase inhibitors in pediatrics. We examined 1624 pediatric adverse events with imatinib, dasatinib, sorafenib, pazopanib, crizotinib, and ruxolitinib reported to the Food and Drug Administration between January 1, 2015, and August 14, 2020. There were 102 cardiovascular event reports. Hypertension was the most commonly reported cardiovascular event and was most frequently associated with sorafenib and pazopanib. The presence of infection increased the reporting odds of cardiovascular events overall and specifically cardiac arrest, heart failure, and hypertension. These data provide early insight into cardiovascular toxicities with tyrosine kinase inhibitor use in pediatrics.

Somatic growth in single ventricle patients: A systematic review and meta-analysis.

AIM: To map somatic growth patterns throughout Fontan palliation and summarise evidence on its key modifiers. METHODS: Databases were searched for relevant articles published from January 2000 to December 2021. Height and weight z scores at each time point (birth, Glenn procedure, Fontan procedure and >5 years after Fontan completion) were pooled using a random effects meta-analysis. A random effects meta-regression model was fitted to model the trend in z scores over time. RESULTS: Nineteen studies fulfilled eligibility criteria, yielding a total of 2006 participants. The z scores for height and weight were markedly reduced from birth to the interstage period, but recovered by about 50% following the Glenn procedure. At >10 years after the Fontan procedure, the z scores for weight seemed to normalise despite persistent lower height, resulting in increased body mass index. The review revealed a number of modifiers of somatic growth, including aggressive nutritional management, timing of Glenn/Fontan, prompt resolution of complications and obesity prevention programmes in adolescence and adulthood. CONCLUSION: This review mapped the somatic growth of single ventricle patients and summarised key modifiers that may be amendable to improvement. These data provide guidance on strategies to further optimise somatic growth in this population and may serve as a benchmark for clinical follow-up.

Exercise Stress Real-Time Cardiac Magnetic Resonance Imaging for Noninvasive Characterization of Heart Failure With Preserved Ejection Fraction: The HFpEF-Stress Trial.

BACKGROUND: Right heart catheterization using exercise stress is the reference standard for the diagnosis of heart failure with preserved ejection fraction (HFpEF) but carries the risk of the invasive procedure. We hypothesized that real-time cardiac magnetic resonance (RT-CMR) exercise imaging with pathophysiologic data at excellent temporal and spatial resolution may represent a contemporary noninvasive alternative for diagnosing HFpEF. METHODS: The HFpEF-Stress trial (CMR Exercise Stress Testing in HFpEF; URL: https://www.clinicaltrials.gov; Unique identifier: NCT03260621. URL: https://dzhk.de/; Unique identifier: DZHK-17) prospectively recruited 75 patients with echocardiographic signs of diastolic dysfunction and dyspnea on exertion (E/e'>8, New York Heart Association class ≥II) to undergo echocardiography, right heart catheterization, and RT-CMR at rest and during exercise stress. HFpEF was defined according to pulmonary capillary wedge pressure (≥15 mm Hg at rest or ≥25 mm Hg during exercise stress). RT-CMR functional assessments included time-volume curves for total and early (1/3) diastolic left ventricular filling, left atrial (LA) emptying, and left ventricular/LA long axis strain. RESULTS: Patients with HFpEF (n=34; median pulmonary capillary wedge pressure at rest, 13 mm Hg; at stress, 27 mm Hg) had higher E/e' (12.5 versus 9.15), NT-proBNP (N-terminal pro-B-type natriuretic peptide; 255 versus 75 ng/L), and LA volume index (43.8 versus 36.2 mL/m2) compared with patients with noncardiac dyspnea (n=34; rest, 8 mm Hg; stress, 18 mm Hg; P≤0.001 for all). Seven patients were excluded because of the presence of non-HFpEF cardiac disease causing dyspnea on imaging. There were no differences in RT-CMR left ventricular total and early diastolic filling at rest and during exercise stress (P≥0.164) between patients with HFpEF and noncardiac dyspnea. RT-CMR revealed significantly impaired LA total and early (P<0.001) diastolic emptying in patients with HFpEF during exercise stress. RT-CMR exercise stress LA long axis strain was independently associated with HFpEF (adjusted odds ratio, 0.657 [95% CI, 0.516-0.838]; P=0.001) after adjustment for clinical and imaging measures and emerged as the best predictor for HFpEF (area under the curve at rest 0.82 versus exercise stress 0.93; P=0.029). CONCLUSIONS: RT-CMR allows highly accurate identification of HFpEF during physiologic exercise and qualifies as a suitable noninvasive diagnostic alternative. These results will need to be confirmed in multicenter prospective research studies to establish widespread routine clinical use. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03260621. URL: https://dzhk.de/; Unique identifier: DZHK-17.

Impact of Socioeconomic Status, Race and Ethnicity, and Geography on Prenatal Detection of Hypoplastic Left Heart Syndrome and Transposition of the Great Arteries.

BACKGROUND: Prenatal detection (PND) has benefits for infants with hypoplastic left heart syndrome (HLHS) and transposition of the great arteries (TGA), but associations between sociodemographic and geographic factors with PND have not been sufficiently explored. This study evaluated whether socioeconomic quartile (SEQ), public insurance, race and ethnicity, rural residence, and distance of residence (distance and driving time from a cardiac surgical center) are associated with the PND or timing of PND, with a secondary aim to analyze differences between the United States and Canada. METHODS: In this retrospective cohort study, fetuses and infants <2 months of age with HLHS or TGA admitted between 2012 and 2016 to participating Fetal Heart Society Research Collaborative institutions in the United States and Canada were included. SEQ, rural residence, and distance of residence were derived using maternal census tract from the maternal address at first visit. Subjects were assigned a SEQ z score using the neighborhood summary score or Canadian Chan index and separated into quartiles. Insurance type and self-reported race and ethnicity were obtained from medical charts. We evaluated associations among SEQ, insurance type, race and ethnicity, rural residence, and distance of residence with PND of HLHS and TGA (aggregate and individually) using bivariate analysis with adjusted associations for confounding variables and cluster analysis for centers. RESULTS: Data on 1862 subjects (HLHS: n=1171, 92% PND; TGA: n=691, 58% PND) were submitted by 21 centers (19 in the United States). In the United States, lower SEQ was associated with lower PND in HLHS and TGA, with the strongest association in the lower SEQ of pregnancies with fetal TGA (quartile 1, 0.78 [95% CI, 0.64-0.85], quartile 2, 0.77 [95% CI, 0.64-0.93], quartile 3, 0.83 [95% CI, 0.69-1.00], quartile 4, reference). Hispanic ethnicity (relative risk, 0.85 [95% CI, 0.72-0.99]) and rural residence (relative risk, 0.78 [95% CI, 0.64-0.95]) were also associated with lower PND in TGA. Lower SEQ was associated with later PND overall; in the United States, rural residence and public insurance were also associated with later PND. CONCLUSIONS: We demonstrate that lower SEQ, Hispanic ethnicity, and rural residence are associated with decreased PND for TGA, with lower SEQ also being associated with decreased PND for HLHS. Future work to increase PND should be considered in these specific populations.

Impact of the new UNOS donor heart allocation system on waitlist outcomes and early posttransplant mortality among adults with congenital heart disease.

Adults with congenital heart disease (ACHD) experience worse waitlist outcomes and higher early posttransplant mortality compared to non-ACHD patients. On October 18, 2018; the UNOS donor heart allocation system was redesigned giving unique listing status to ACHD patients. The impact of this change on outcomes in transplant-listed patients is unstudied. Using the Scientific Registry of Transplant Recipients (SRTR) we compared ACHD patients listed for the first-time for heart transplantation from two eras of equal duration. We analyzed waitlist outcomes, posttransplant mortality and length of stay among ACHD patients in both eras and between ACHD and non-ACHD patients in the new era. Of 12 723 listed patients, 535 had ACHD (293 in the new era) and 12 188 did not (6258 in the new era). A total of 163 (56%) ACHD patients in the new era versus 150 (62%) in the prior era were transplanted; 11 (3.8%) versus 15 (6.2%) died on the waitlist; 32 (11%) versus 35 (14%) were delisted and 15 (9.2%) versus 19 (12.7%) died within 30 days of transplant, respectively. The new UNOS donor heart allocation system improved waitlist time and decreased the proportion not transplanted during the first 300 days after listing among ACHD patients without altering early posttransplant outcomes or significantly changing the gap in outcomes compared to non-ACHD patients.

Artificial intelligence in pediatric cardiology: taking baby steps in the big world of data.

PURPOSE OF REVIEW: Artificial intelligence (AI) has changed virtually every aspect of modern life, and medicine is no exception. Pediatric cardiology is both a perceptual and a cognitive subspecialty that involves complex decision-making, so AI is a particularly attractive tool for this medical discipline. This review summarizes the foundational work and incremental progress made as AI applications have emerged in pediatric cardiology since 2020. RECENT FINDINGS: AI-based algorithms can be useful for pediatric cardiology in many areas, including: (1) clinical examination and diagnosis, (2) image processing, (3) planning and management of cardiac interventions, (4) prognosis and risk stratification, (5) omics and precision medicine, and (6) fetal cardiology. Most AI initiatives showcased in medical journals seem to work well in silico, but progress toward implementation in actual clinical practice has been more limited. Several barriers to implementation are identified, some encountered throughout medicine generally, and others specific to pediatric cardiology. SUMMARY: Despite barriers to acceptance in clinical practice, AI is already establishing a durable role in pediatric cardiology. Its potential remains great, but to fully realize its benefits, substantial investment to develop and refine AI for pediatric cardiology applications will be necessary to overcome the challenges of implementation.

Epigenetic Metabolic Reprogramming of Right Ventricular Fibroblasts in Pulmonary Arterial Hypertension: A Pyruvate Dehydrogenase Kinase-Dependent Shift in Mitochondrial Metabolism Promotes Right Ventricular Fibrosis.

RATIONALE: Right ventricular (RV) fibrosis in pulmonary arterial hypertension contributes to RV failure. While RV fibrosis reflects changes in the function of resident RV fibroblasts (RVfib), these cells are understudied. OBJECTIVE: Examine the role of mitochondrial metabolism of RVfib in RV fibrosis in human and experimental pulmonary arterial hypertension. METHODS AND RESULTS: Male Sprague-Dawley rats received monocrotaline (MCT; 60 mg/kg) or saline. Drinking water containing no supplement or the PDK (pyruvate dehydrogenase kinase) inhibitor dichloroacetate was started 7 days post-MCT. At week 4, treadmill testing, echocardiography, and right heart catheterization were performed. The effects of PDK activation on mitochondrial dynamics and metabolism, RVfib proliferation, and collagen production were studied in RVfib in cell culture. Epigenetic mechanisms for persistence of the profibrotic RVfib phenotype in culture were evaluated. PDK expression was also studied in the RVfib of patients with decompensated RV failure (n=11) versus control (n=7). MCT rats developed pulmonary arterial hypertension, RV fibrosis, and RV failure. MCT-RVfib (but not left ventricular fibroblasts) displayed excess mitochondrial fission and had increased expression of PDK isoforms 1 and 3 that persisted for >5 passages in culture. PDK-mediated decreases in pyruvate dehydrogenase activity and oxygen consumption rate were reversed by dichloroacetate (in RVfib and in vivo) or siRNA targeting PDK 1 and 3 (in RVfib). These interventions restored mitochondrial superoxide and hydrogen peroxide production and inactivated HIF (hypoxia-inducible factor)-1α, which was pathologically activated in normoxic MCT-RVfib. Redox-mediated HIF-1α inactivation also decreased the expression of TGF-ß1 (transforming growth factor-beta-1) and CTGF (connective tissue growth factor), reduced fibroblast proliferation, and decreased collagen production. HIF-1α activation in MCT-RVfib reflected increased DNMT (DNA methyltransferase) 1 expression, which was associated with a decrease in its regulatory microRNA, miR-148b-3p. In MCT rats, dichloroacetate, at therapeutic levels in the RV, reduced phospho-pyruvate dehydrogenase expression, RV fibrosis, and hypertrophy and improved RV function. In patients with pulmonary arterial hypertension and RV failure, RVfib had increased PDK1 expression. CONCLUSIONS: MCT-RVfib manifest a DNMT1-HIF-1α-PDK-mediated, chamber-specific, metabolic memory that promotes collagen production and RV fibrosis. This epigenetic mitochondrial-metabolic pathway is a potential antifibrotic therapeutic target.

Risk factors for acute kidney injury after pediatric cardiac surgery: a meta-analysis.

BACKGROUND: Cardiac surgery-associated acute kidney injury (AKI) is associated with increased morbidity and mortality in both adults and children. OBJECTIVES: This study aimed to identify clinical risk factors for AKI following cardiac surgery in the pediatric population. DATA SOURCES: PubMed/MEDLINE, Embase, Scopus, and reference lists of relevant articles were searched for studies published by August 2020. STUDY ELIGIBILITY CRITERIA: Studies were included if (1) the population consisted of pediatric patients (< 18 years old), (2) patients underwent cardiac surgery, (3) risk factors were compared between patients who developed AKI and those who did not, and (4) studies were prospective or retrospective observational studies or randomized controlled trials. PARTICIPANTS AND INTERVENTIONS: Children undergoing pediatric cardiac surgery. STUDY APPRAISAL AND SYNTHESIS METHODS: Random-effects meta-analysis was performed, comparing potential risk factors between pediatric patients who developed CS-AKI and those who did not. RESULTS: Sixty-one publications including a total of 19,680 participants (AKI: 7257 participants; no AKI: 12,423 participants) were included from studies published between 2008 and 2020. The pooled estimated incidence of AKI was 34.3% (95% confidence interval 30.0-38.8%, I2 = 96.8%). Binary risk factors that were significantly and consistently associated with AKI were the presence of pulmonary hypertension, cyanotic heart disease, univentricular heart, risk adjustment for congenital heart surgery 1 (RACHS-1) score ≥ 3, vasopressor use, cardiopulmonary bypass use, reoperation, and sepsis. Significant continuous risk factors included younger age, lower body weight, lower preoperative creatinine, higher preoperative estimated glomerular filtration rate (eGFR), higher RACHS-1 score, longer surgery time, longer cardiopulmonary bypass time, longer aortic cross-clamp time, and higher red blood cell transfusion volume. LIMITATIONS: Results are limited by heterogeneity and potential residual confounding. CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS: Our meta-analysis identified clinical risk factors that are associated with AKI in children undergoing cardiac surgery. This might help clinicians anticipate and manage more carefully this population and implement standardized preventive strategies. SYSTEMATIC REVIEW REGISTRATION NUMBER: CRD42021262699. A higher resolution version of the Graphical abstract is available as Supplementary information.

Biomarkers of acute kidney injury after pediatric cardiac surgery: a meta-analysis of diagnostic test accuracy.

Acute kidney injury (AKI) occurs frequently after cardiac surgery in children. Although current diagnostic criteria rely on serum creatinine and urine output, changes occur only after considerable loss of kidney function. This meta-analysis aimed to synthesize the knowledge on novel biomarkers and compare their ability to predict AKI. PubMed/MEDLINE, Embase, Scopus, and reference lists were searched for relevant studies published by March 2021. Diagnostic accuracy parameters were extracted and analyzed using hierarchical summary receiver operating characteristic (HSROC) method. Pooled estimates of the area under the curve (AUC) were calculated using conventional random-effects meta-analysis. Fifty-six articles investigating 49 biomarkers in 8617 participants fulfilled our eligibility criteria. Data from 37 studies were available for meta-analysis. Of the 10 biomarkers suitable for HSROC analysis, urinary neutrophil gelatinase-associated lipocalin (uNGAL) to creatinine (Cr) ratio yielded the highest diagnostic odds ratio (91.0, 95% CI 90.1-91.9), with a sensitivity of 91.3% (95% CI 91.2-91.3%) and a specificity of 89.7% (95% CI 89.6-89.7%). These results were confirmed in pooled AUC analysis, as uNGAL-to-Cr ratio and uNGAL were the only elaborately studied biomarkers (> 5 observations) with pooled AUCs ≥ 0.800. Liver fatty acid-binding protein (L-FABP), serum cystatin C (sCysC), serum NGAL (sNGAL), and interleukin-18 (IL-18) all had AUCs ≥ 0.700. CONCLUSION: A variety of biomarkers have been proposed as predictors of cardiac surgery-associated AKI in children, of which uNGAL was the most prominent with excellent diagnostic qualities. However, more consolidatory evidence will be required before these novel biomarkers may eventually help realize precision medicine in AKI management. WHAT IS KNOWN: • Acute kidney injury (AKI) occurs in about 30-60% of children undergoing cardiac surgery and is associated with increased in-hospital mortality and adverse short-term outcomes. However, in current clinical practice, AKI definitions and detection often rely on changes in serum creatinine and urine output, which are late and insensitive markers of kidney injury. • Although various novel biomarkers have been studied for the diagnosis of AKI in children after cardiac surgery, it remains unclear how these compare to one another in terms of diagnostic accuracy. WHAT IS NEW: • Pooled analyses suggest that for the diagnosis of AKI in children who underwent cardiac surgery, NGAL is the most accurate among the most frequently studied biomarkers. • A number of other promising biomarkers have been reported, although they will require further research into their diagnostic accuracy and clinical applicability.

Left ventricular myocardial work indices in pediatric hypertension: correlations with conventional echocardiographic assessment and subphenotyping.

Myocardial work (MW) is a novel parameter that incorporates non-invasive estimates of left ventricular (LV) systolic pressure into the interpretation of strain, thus overcoming the limitations of load dependency traditionally encountered with LV fractional shortening (LVFS), ejection fraction (LVEF), and global longitudinal strain (GLS). However, data on MW in the pediatric population with hypertension are lacking. Conventional markers of LV function and MW indices were obtained from 88 echocardiographic examinations in 76 children with hypertension (47 males, 15.5 ± 2.96 years). When compared with a previously published cohort of 52 healthy controls, global work index (GWI) and global constructive work (GCW) were both significantly elevated while LVEF and GLS were not impaired but rather mildly increased. On multivariable analysis, GWI was correlated with systolic blood pressure (slope = + 16, p < 0.001) and GLS (slope = -100, p < 0.001), while GCW was correlated with systolic blood pressure (slope = + 18, p < 0.001), GLS (slope = -101, p < 0.001), male sex (slope = -75, p = 0.016), and LV mass (slope = -0.93, p < 0.001). Global wasted work (GWW) was correlated with age at echo visit (slope = -4.5, p = 0.005) and GLS (slope = + 5.5, p < 0.001). The opposite occurred for global work efficiency (GWE; slope = + 0.20, p = 0.011, and slope = -0.48, p < 0.001, respectively). Principal component analysis and k-means clustering revealed 4 subphenotypes which differed in terms of etiology, afterload, and compensation stage of the disease.    Conclusion: Non-invasive MW shows a good correlation with conventional markers of LV function and may help refine the assessment of hypertensive heart disease in children. What is Known: • Myocardial work (MW) is a novel parameter that incorporates non-invasive estimates of left ventricular (LV) systolic pressure into the interpretation of strain, thereby accounting for both deformation and afterload. • Although the usefulness of MW in the assessment of myocardial function beyond conventional markers has been demonstrated in various clinical populations, data in the pediatric population with hypertension are currently lacking. What is New: • Compared to normal values in healthy children, global work index and global constructive work were increased in those with hypertension, while LV ejection fraction and global longitudinal strain were not impaired. • Machine learning identified 4 subphenotypes which differed in terms of etiology, afterload, and compensation stage of the disease.