Predictors of Catastrophic Adverse Outcomes in Children With Pulmonary Hypertension Undergoing Cardiac Catheterization: A Multi-Institutional Analysis From the Pediatric Health Information Systems Database

Effect of patient factors, center, and era on Fontan timing: An observational study using the Pediatric Health Information Systems Database

BACKGROUND

There are no consensus guidelines defining optimal timing for the Fontan operation, the last planned surgery in staged palliation for single-ventricle heart disease.

OBJECTIVES

Identify patient-level characteristics, center-level variation, and secular trends driving Fontan timing.

METHODS

A retrospective observational study of subjects who underwent Fontan from 2007 to 2021 at centers in the Pediatric Health Information Systems database was performed using linear mixed-effects modeling in which age at Fontan was regressed on patient characteristics and date of operation with center as random effect.

RESULTS

We included 10,305 subjects (40.4% female, 44% non-white) at 47 centers. Median age at Fontan was 3.4 years (IQR 2.6-4.4). Hypoplastic left heart syndrome (-4.4 months, 95%CI -5.5 to -3.3) and concomitant conditions (-2.6 months, 95%CI -4.1 to -1.1) were associated with younger age at Fontan. Subjects with technology-dependence (+4.6 months, 95%CI 3.1-6.1) were older at Fontan. Black (+4.1 months, 95%CI 2.5-5.7) and Asian (+8.3 months, 95%CI 5.4-11.2) race were associated with older age at Fontan. There was significant variation in Fontan timing between centers. Center accounted for 10% of variation (ICC 0.10, 95%CI 0.07-0.14). Center surgical volume was not associated with Fontan timing (P = .21). Operation year was associated with age at Fontan, with a 3.1 month increase in age for every 5 years (+0.61 months, 95%CI 0.48-0.75).

CONCLUSIONS

After adjusting for patient-level characteristics there remains significant inter-center variation in Fontan timing. Age at Fontan has increased. Future studies addressing optimal Fontan timing are warranted.

A single institution anesthetic experience with catheterization of pediatric pulmonary hypertension patients

Cardiac catheterization remains the gold standard for the diagnosis and management of pediatric pulmonary hypertension (PH). There is lack of consensus regarding optimal anesthetic and airway regimen. This retrospective study describes the anesthetic/airway experience of our single center cohort of pediatric PH patients undergoing catheterization, in which obtaining hemodynamic data during spontaneous breathing is preferential. A total of 448 catheterizations were performed in 232 patients. Of the 379 cases that began with a natural airway, 274 (72%) completed the procedure without an invasive airway, 90 (24%) received a planned invasive airway, and 15 (4%) required an unplanned invasive airway. Median age was 3.4 years (interquartile range [IQR] 0.7-9.7); the majority were either Nice Classification Group 1 (48%) or Group 3 (42%). Vasoactive medications and cardiopulmonary resuscitation were required in 14 (3.7%) and eight (2.1%) cases, respectively; there was one death. Characteristics associated with use of an invasive airway included age <1 year, Group 3, congenital heart disease, trisomy 21, prematurity, bronchopulmonary dysplasia, WHO functional class III/IV, no PH therapy at time of case, preoperative respiratory support, and having had an intervention (p < 0.05). A composite predictor of age <1 year, Group 3, prematurity, and any preoperative respiratory support was significantly associated with unplanned airway escalation (26.7% vs. 6.9%, odds ratio: 4.9, confidence interval: 1.4-17.0). This approach appears safe, with serious adverse event rates similar to previous reports despite the predominant use of natural airways. However, research is needed to further investigate the optimal anesthetic regimen and respiratory support for pediatric PH patients undergoing cardiac catheterization.

Long-term outcome of children with newly diagnosed pulmonary arterial hypertension: results from the global TOPP registry

BACKGROUND AND AIMS

The Tracking Outcomes and Practice in Pediatric Pulmonary Hypertension (TOPP) registry is a global network established to gain insights into the disease course and long-term outcomes of paediatric pulmonary arterial hypertension (PAH). Previously published cohorts in paediatric PAH are obscured by survival bias due to the inclusion of both prevalent (previously diagnosed) and incident (newly diagnosed) patients. The current study aims to describe long-term outcome and its predictors in paediatric PAH, exclusively of newly diagnosed patients.

METHODS AND RESULTS

Five hundred thirty-one children with confirmed pulmonary hypertension, aged ≥3 months and <18 years, were enrolled in the real-world TOPP registry at 33 centres in 20 countries, from 2008 to 2015. Of these, 242 children with newly diagnosed PAH with at least one follow-up visit were included in the current outcome analyses. During long-term follow-up, 42 (17.4%) children died, 9 (3.7%) underwent lung transplantation, 3 (1.2%) atrial septostomy, and 9 (3.7%) Potts shunt palliation (event rates: 6.2, 1.3, 0.4, and 1.4 events per 100 person-years, respectively). One-, three-, and five-year survival free from adverse outcome was 83.9%, 75.2%, and 71.8%, respectively.Overall, children with open (unrepaired or residual) cardiac shunts had the best survival rates. Younger age, worse World Health Organization functional class, and higher pulmonary vascular resistance index were identified as independent predictors of long-term adverse outcome. Younger age, higher mean right atrial pressure, and lower systemic venous oxygen saturation were specifically identified as independent predictors of early adverse outcome (within 12 months after enrolment).

CONCLUSION

This comprehensive analysis of survival from time of diagnosis in a large exclusive cohort of children newly diagnosed with PAH describes current-era outcome and its predictors.

Pulmonary hypertension

Pulmonary hypertension encompasses a range of conditions directly or indirectly leading to elevated pressures within the pulmonary arteries. Five main groups of pulmonary hypertension are recognized, all defined by a mean pulmonary artery pressure of >20 mmHg: pulmonary arterial hypertension (rare), pulmonary hypertension associated with left-sided heart disease (very common), pulmonary hypertension associated with lung disease (common), pulmonary hypertension associated with pulmonary artery obstructions, usually related to thromboembolic disease (rare), and pulmonary hypertension with unclear and/or multifactorial mechanisms (rare). At least 1% of the world's population is affected, with a greater burden more likely in low-income and middle-income countries. Across all its forms, pulmonary hypertension is associated with adverse vascular remodelling with obstruction, stiffening and vasoconstriction of the pulmonary vasculature. Without proactive management this leads to hypertrophy and ultimately failure of the right ventricle, the main cause of death. In older individuals, dyspnoea is the most common symptom. Stepwise investigation precedes definitive diagnosis with right heart catheterization. Medical and surgical treatments are approved for pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension. There are emerging treatments for other forms of pulmonary hypertension; but current therapy primarily targets the underlying cause. There are still major gaps in basic, clinical and translational knowledge; thus, further research, with a focus on vulnerable populations, is needed to better characterize, detect and effectively treat all forms of pulmonary hypertension.

Quantitative Measures of Right Ventricular Size and Function by Echocardiogram Correlate with Cardiac Catheterization Hemodynamics in Congenital Diaphragmatic Hernia

OBJECTIVE

To evaluate associations between cardiac catheterization (cath) hemodynamics, quantitative measures of right ventricular (RV) function by echocardiogram, and survival in patients with congenital diaphragmatic hernia (CDH).

STUDY DESIGN

This single-center retrospective cohort study enrolled patients with CDH who underwent index cath from 2003 to 2022. Tricuspid annular plane systolic excursion z score, RV fractional area change, RV free wall and global longitudinal strain, left ventricular (LV) eccentricity index, RV/LV ratio, and pulmonary artery acceleration time were measured from preprocedure echocardiograms. Associations between hemodynamic values, echocardiographic measures, and survival were evaluated by Spearman correlation and Wilcoxon rank sum test, respectively.

RESULTS

Fifty-three patients (68% left-sided, 74% liver herniation, 57% extracorporeal membrane oxygenation, 93% survival) underwent cath (39 during index hospitalization, 14 later) including device closure of a patent ductus arteriosus in 5. Most patients (n = 31, 58%) were on pulmonary hypertension treatment at cath, most commonly sildenafil (n = 24, 45%) and/or intravenous treprostinil (n = 16, 30%). Overall, hemodynamics were consistent with precapillary pulmonary hypertension. Pulmonary capillary wedge pressure was >15 mm Hg in 2 patients (4%). Lower fractional area change and worse ventricular strain were associated with higher pulmonary artery pressure while higher LV eccentricity index and higher RV/LV ratio were associated with both higher pulmonary artery pressure and higher pulmonary vascular resistance. Hemodynamics did not differ based on survival status.

CONCLUSIONS

Worse RV dilation and dysfunction by echocardiogram correlate with higher pulmonary artery pressure and pulmonary vascular resistance on cath in this CDH cohort. These measures may represent novel, noninvasive clinical trial targets in this population.

Treprostinil in Neonates with Congenital Diaphragmatic Hernia-Related Pulmonary Hypertension

OBJECTIVE

To describe our experience with treprostinil, evaluate correlations with cardiac function, and assess for adverse effects in neonates with congenital diaphragmatic hernia-related pulmonary hypertension (CDH-PH).

STUDY DESIGN

A retrospective review of a single-center prospective registry at a quaternary care children's hospital. Patients included in the study had CDH-PH treated with treprostinil between April 2013 and September 2021. Assessed outcomes were brain-type natriuretic peptide levels and quantitative echocardiographic parameters collected at baseline, 1 week, 2 weeks, and 1 month after treprostinil initiation. Right ventricular (RV) function was assessed by tricuspid annular plane systolic excursion Z-score and speckle tracking echocardiography (global longitudinal and free wall strain). Septal position and left ventricular (LV) compression were assessed by eccentricity index and M-mode Z-scores.

RESULTS

Fifty-one patients were included, with an average expected/observed lung-to-head ratio of 28.4 ± 9.0%. Most patients required extra-corporeal membrane oxygenation (n = 45, 88%). Survival to hospital discharge was 31/49 (63%). Treprostinil was initiated at a median age of 19 days with a median effective dose of 34 ng/kg/minute. Median baseline brain-type natriuretic peptide level decreased from 416.9 pg/mL to 120.5 pg/mL after 1 month. Treprostinil was associated with improved tricuspid annular plane systolic excursion Z-score, RV global longitudinal strain, RV free wall strain, LV eccentricity index, and LV diastolic and systolic dimensions, reflecting less compression by the RV, regardless of ultimate patient survival. No serious adverse effects were recorded.

CONCLUSIONS

In neonates with CDH-PH, treprostinil administration is well tolerated and is associated with improved RV size and function.

Hemodynamic Characterization of Neonates With Congenital Diaphragmatic Hernia-Associated Pulmonary Hypertension by Cardiac Catheterization

We examined the results of cardiac catheterization in infants with congenital diaphragmatic hernia (CDH) from 2009 to 2020. Catheterization confirmed pulmonary arterial hypertension in all cases (n =  17) and identified left ventricular (LV) diastolic dysfunction (LVDD) in 53%. LVDD was associated with greater respiratory morbidity. Preprocedural noninvasive assessment showed inconsistent agreement with catheterization results.

Right Heart Catheterization in Pediatric Pulmonary Arterial Hypertension: Insights and Outcome from a Large Tertiary Center

Aim: To define the clinical characteristics, hemodynamics, and adverse events for pediatric patients with pulmonary arterial hypertension (PAH) undergoing right heart catheterization (RHC). Methods: The large referral single center data of 591 diagnostic RHC procedures performed between 2005 and 2020 on pediatric PAH patients was retrospectively collected and analyzed. Results: A total of 591 RHC procedures performed on 469 patients with congenital heart disease (CHD)-PAH (median age 8.8 years, 7.9% New York Heart Association (NYHA) class > II, 1.5% with syncope) and 122 patients with idiopathic PAH (median age of 9.0 years, 27.0% NYHA class > II, 27.0% with syncope) were included. Of those, 373 (63.1%) procedures were performed under general anesthesia. Eighteen patients (18/591, 3.0%) suffered adverse events (mainly pulmonary hypertensive crisis, PHC, n = 17) during the RHC procedure, including 14 idiopathic pulmonary arterial hypertension (IPAH) patients and 4 CHD-PAH patients, and one IPAH patient died in hospital 63 hours after RHC. The risk of developing PHC was significantly increased in patients with IPAH (OR = 14.02, 95%CI: 4.49−43.85, p < 0.001), atrial blood gas pH < 7.35 (OR = 12.504, 95%CI: 3.545−44.102, p < 0.001) and RAP > 14 mmHg (OR = 10.636, 95%CI: 3.668−30.847, p < 0.001). Conclusions: RHC is generally a low-risk procedure in pediatric patients with PAH. However, PHC occur in approximately 3% of patients. Therefore, RHC should be performed in a large, experienced referral pediatric cardiology center, especially in pediatric patients with IPAH requiring general anesthesia.

Pulmonary hypertensive crisis in children with pulmonary arterial hypertension undergoing cardiac catheterization

Pediatric patients with pulmonary arterial hypertension (PAH) are considered to be at risk for pulmonary hypertensive crisis (PHC) or even death during right heart catheterization (RHC). This retrospective study was designed to identify the risks and clinical characteristics associated with PHC in pediatric PAH patients. We included 163 consecutive procedures from 147 pediatric patients diagnosed with PAH who underwent diagnostic RHC in Beijing Anzhen Hospital between January 2007 and December 2020. The average patient age was 9.0 ± 4.7 years and 84 (51.5%) were females. Before RHC, over 20% of patients were in New York Heart Association (NYHA) class III-IV. Sedation or general intravenous anesthesia was used in 103 procedures (63.2%), with spontaneous breathing in 93.2%. PHC occurred in 19 patients (11.7%), 5 (3.1%) required cardiac compression, and 1 died (0.6%). Compared to patients without PHC, those who experienced PHC were more likely to be in NYHA class III-IV (p = 0.012) before RHC, require sedation (p = 0.011), had echocardiographic indices of higher peak tricuspid regurgitation velocity (p = 0.018), and right ventricle (RV) to left ventricle (LV) ratio (p < 0.001). Multivariate logistic regression for PHC identified the need for sedation and a higher RV/LV ratio as independent predictors. In conclusion, the risk of RHC remains significant in children with PAH, particularly in those with severe RV dilation who require sedation during cardiac catheterization. Comprehensive evaluation, close monitoring, and appropriate treatment before and during the procedure are essential for reducing mortality.

Anesthesia in Children With Pulmonary Hypertension: Clinically Significant Serious Adverse Events Associated With Cardiac Catheterization and Noncardiac Procedures

OBJECTIVES

To determine the incidence of clinically significant serious adverse events in a contemporary population of pediatric patients with pulmonary hypertension who require anesthesia and identify factors associated with adverse outcomes.

DESIGN

A retrospective, cross-sectional study.

SETTING

A single-center quaternary-care freestanding children's hospital in the northeastern United States.

PARTICIPANTS

Pediatric patients with pulmonary hypertension based on hemodynamic criteria on cardiac catheterization during a 3-year period from 2015 to 2018.

INTERVENTIONS

Anesthesia care for cardiac catheterization, noncardiac surgery, and diagnostic imaging.

MEASUREMENTS AND MAIN RESULTS

Two hundred forty-nine children underwent 862 procedures, 592 for cardiac catheterization and 278 for noncardiac surgery and diagnostic imaging. The median age was 1.6 years, and the weight was 9.5 lbs. On index catheterization, median pulmonary artery pressure was 36 mmHg, and the pulmonary vascular resistance was 5.1 indexed Wood units. Ten percent of anesthetics were performed with a natural airway, and 80% used volatile anesthetics. Serious adverse events occurred in 26% of procedures (confidence interval [CI], 22%-30%). The rate of periprocedural cardiac arrest was 8 per 1,000 anesthetic administrations. In multivariate analysis, younger age (adjusted odds ratio [aOR], 1.4 per year; CI, 1.1-1.9; p = 0.01), location in the catheterization laboratory (aOR, 5.1; CI, 1.7-16; p = 0.004), and longer procedure duration (aOR, 1.3 per 30 minutes; CI, 1.1-1.4; p = 0.001) were associated with serious adverse events. Patients with a tracheostomy in place were less likely to experience an adverse event (aOR, 0.1; CI, 0.04-0.5; p = 0.001). The primary anesthetic technique was not associated with adverse events. Interventional cardiac catheterization was associated with an increased incidence of adverse events compared with diagnostic catheterization (42% v 21%; OR, 2.23; CI, 1.5-3.3; p < 0.001).

CONCLUSIONS

Serious adverse events were common in this cohort. Careful planning to minimize anesthesia time in young children with pulmonary hypertension should be undertaken, and these factors considered in designing risk mitigation strategies.

Long-Term Follow-Up of Pediatric Patients with Severe Postoperative Pulmonary Hypertension After Correction of Congenital Heart Defects

The surgical repair of congenital heart defects in children with preoperative pulmonary hypertension (PH) is to varying degree associated with the occurrence of postoperative PH. The objective of this study was to follow up children with severe postoperative PH (pulmonary arterial/aortic pressure ratio ≥ 1.0) to evaluate if pulmonary arterial pressure spontaneously normalized or needed PH-targeting therapy and to identify potential high-risk diagnoses for bad outcome. Twenty-five children who developed clinically significant severe PH on at least three occasions postoperatively were included in the follow-up (20-24 years). Data from chart reviews, echocardiographic investigations, and questionnaires were obtained. Three children died within the first year after surgery. Three children were lost to follow-up. The remaining 17 children normalized their pulmonary arterial pressure without the use of PH-targeting drugs at any time during the follow-up. Two children had a remaining mild PH with moderate mitral valve insufficiency. All three children with bad outcome had combined cardiac lesions causing post-capillary pulmonary hypertension. Normalization of the pulmonary arterial pressure occurred in almost all children with severe postoperative PH, without any need of supplemental PH-targeting therapies. All children with bad outcome had diagnoses conformable with post-capillary PH making the use of PH-targeting therapies relatively contraindicated. These data emphasize the need to perform randomized, blinded trials on the use of PH-targeting drugs in children with postoperative PH before accepting it as an indication for routine treatment.

Cardiac catheterization in pediatric pulmonary hypertension: a systematic and practical approach

Significant progress in the understanding of the etiology, epidemiology, pathobiology and prognosis of pulmonary hypertension (PH) has been made over the last years. Especially in the pediatric patient population the etiology of PH is very heterogeneous. Nevertheless, the most recent change of the definition of PH to a mean pulmonary artery pressure (mPAP) >20 mmHg has been accepted by pediatricians for uniformity and concordance with adult physicians. Based on the diverse underlying medical conditions leading to PH, a comprehensive and systematic approach for diagnosis and treatment is mandatory. Cardiac catheterization remains the gold standard for invasive assessment and acute vasoreactivity testing (AVT) additionally providing detailed information about nature of PH. In most patients repeat cardiac catheterization may be helpful for evaluation of response to targeted PH treatment, risk stratification and indication for lung transplantation. However, the information and results taken from cardiac catheterization should be interpreted by experienced investigators only who are familiar with confounding factors that may influence the results. Here we provide an overview of current recommendations for invasive hemodynamic evaluation in pediatric PH. We point out different patient scenarios and provide a structured approach for AVT and response interpretation.

Pediatric Pulmonary Hypertension: Definitions, Mechanisms, Diagnosis, and Treatment

Pediatric pulmonary hypertension (PPH) is a multifactorial disease with diverse etiologies and presenting features. Pulmonary hypertension (PH), defined as elevated pulmonary artery pressure, is the presenting feature for several pulmonary vascular diseases. It is often a hidden component of other lung diseases, such as cystic fibrosis and bronchopulmonary dysplasia. Alterations in lung development and genetic conditions are an important contributor to pediatric pulmonary hypertensive disease, which is a distinct entity from adult PH. Many of the causes of pediatric PH have prenatal onset with altered lung development due to maternal and fetal conditions. Since lung growth is altered in several conditions that lead to PPH, therapy for PPH includes both pulmonary vasodilators and strategies to restore lung growth. These strategies include optimal alveolar recruitment, maintaining physiologic blood gas tension, nutritional support, and addressing contributing factors, such as airway disease and gastroesophageal reflux. The outcome for infants and children with PH is highly variable and largely dependent on the underlying cause. The best outcomes are for neonates with persistent pulmonary hypertension (PPHN) and reversible lung diseases, while some genetic conditions such as alveolar capillary dysplasia are lethal. © 2021 American Physiological Society. Compr Physiol 11:2135-2190, 2021.

Trends in Discharge Prescription of Digoxin After Norwood Operation: An Analysis of Data from the Pediatric Health Information System (PHIS) Database

Quality improvement efforts have focused on reducing interstage mortality for infants with hypoplastic left heart syndrome (HLHS). In 1/2016, two publications reported that use of digoxin was associated with reduced interstage mortality. The degree to which these findings have affected real world practice has not been evaluated. The discharge medications of neonates with HLHS undergoing Norwood operation between 1/2007 and 12/2018 at Pediatric Health Information Systems Database hospitals were studied. Mixed effects models were calculated to evaluate the hypothesis that the likelihood of digoxin prescription increased after 1/2016, adjusting for measurable confounders with furosemide and aspirin prescription measured as falsification tests. Interhospital practice variation was measured using the median odds ratio. Over the study period, 6091 subjects from 45 hospitals were included. After adjusting for measurable covariates, discharge after 1/2016 was associated with increased odds of receiving digoxin (OR 3.9, p < 0.001). No association was seen between date of discharge and furosemide (p = 0.26) or aspirin (p = 0.12). Prior to 1/2016, the likelihood of receiving digoxin was decreasing (OR 0.9 per year, p < 0.001), while after 1/2016 the rate has increased (OR 1.4 per year, p < 0.001). However, there remains significant interhospital variation in the likelihood of receiving digoxin even after adjusting for known confounders (median odds ratio = 3.5, p < 0.0001). Following publication of studies describing an association between digoxin and improved interstage survival, the likelihood of receiving digoxin at discharge increased without similar changes for furosemide or aspirin. Despite concerted efforts to standardize interstage care, interhospital variation in pharmacotherapy in this vulnerable population persists.

Risk Factors for Adverse Events in Children with Pulmonary Hypertension Undergoing Cardiac Catheterization

Pulmonary hypertension (PH) can lead to progressive heart failure with high morbidity and mortality. Cardiac catheterization (CC) is the gold standard for diagnosis and response to vasodilatory medications. The invasive nature of CC and associated anesthesia predispose this patient population to adverse events including death. Catheterization records were queried from 1/1/2011 to 10/31/2016. Patients with PH, defined as pulmonary vascular resistance (PVR) greater than 3 WU m², pulmonary artery pressure above 20 mmHg, and pulmonary wedge pressure less than or equal to 15 mmHg, who underwent hemodynamic CC were included in this retrospective study. Both patients with and without congenital heart disease were included. There were 198 CC in 191 patients. Adverse events (n = 28, 14.1%) included cardiac arrest, increased respiratory support requiring ICU care, PH crisis, bradycardia/hypotension requiring intervention, and arrhythmias. Odds of an adverse event increased by 22% for every 15-min increase in procedure times (OR 1.22, CI 1.01-1.39, p = 0.002) and were significantly increased for procedures longer than 80 min (OR 3.75, CI 1.56-9.00, p = 0.007) (Fig. 1). Patients with an adverse event had higher mean pulmonary artery pressures while breathing oxygen (43 [35-58] versus 34 [27-44] mmHg, p = 0.017) and oxygen with inhaled nitric oxide (37 [32-56] versus 32 [25-40] mmHg, p = 0.026). Females carried more risk than males (OR 3.88, CI 1.44-10.40, p = 0.007). Younger age, medication regimens, prematurity, and genetic disease did not carry an increased risk. Adverse events are common in pediatric patients with PH undergoing CC. The risk of adverse events correlates with greater procedure times and higher mean pulmonary artery pressure. Minimizing procedure time may improve patient outcomes.

Prognostic Value of Change in Cardiac Index After Prostacyclin Initiation in Pediatric Pulmonary Hypertension

Invasive hemodynamic assessment remains the gold standard for the diagnosis of pediatric pulmonary hypertension and for longitudinal assessment of response to therapy. This analysis sought to describe the changes in hemodynamic variables after initiation of prostacyclin therapy and determine which changes bear predictive power of adverse clinical outcomes. A retrospective chart review of established patients at Cincinnati Children's Hospital with pulmonary arterial hypertension (PAH) who required prostacyclin therapy between 2004 and 2018 was performed. The baseline hemodynamic parameters at diagnosis as well as change in those parameters between initial catheterization and post-prostacyclin initiation catheterization were independent variables. Cox proportional hazard regression and recursive partitioning analysis were used to characterize which hemodynamic factors predicted the composite adverse outcome (CAO) defined as death, lung transplantation, or reverse Pott's shunt surgery. During the study period, 29 patients met inclusion criteria in which there were 7 CAOs: 4 deaths, 3 lung transplants, and 2 reverse Pott's shunts. Median time between catheterizations was 86 days and between the initiation of prostacyclin therapy and the second catheterization was 54 days. Cox regression revealed that only baseline pulmonary artery pressure (> 51 mmHg) and a failure to increase cardiac index illustrated statistically significant hazard for occurrence of the CAO (p < 0.01). These criteria significantly dichotomized the population in a Kaplan-Meier analysis into likelihoods of experiencing the CAO. While controlling for other hemodynamic variables, the absence of augmentation of cardiac index after the initiation of prostacyclin therapy is a valuable prognostic indicator of adverse PAH outcomes in pediatrics.

Bronchopulmonary dysplasia requiring tracheostomy: A review of management and outcomes

Bronchopulmonary Dysplasia (BPD) is a pulmonary disease affecting newborns, commonly those with prematurity or low birth weight. Its pathogenesis involves underdevelopment of lung tissue with subsequent limitations in ventilation and oxygenation, resulting in impaired postnatal alveolarization. Despite advances in care with improved survival, BPD remains a prevalent comorbidity of prematurity. In severe cases, management may involve mechanical ventilation via tracheostomy. BPD's demand for multidisciplinary care compounds the challenges in management of this condition. Here, we review existing literature: the history of disease, criteria for diagnosis, pathogenesis, and modes of treatment with a focus on the severe subtype: that which is associated with pulmonary hypertension (PAH) for which tracheostomy is often required to facilitate long-term mechanical ventilation. We review the current recommendations for tracheostomy and decannulation.

Interhospital Variation in the Costs of Pediatric/Congenital Cardiac Catheterization Laboratory Procedures: Analysis of Data From the Pediatric Health Information Systems Database

Background

Cardiac catheterization is an important but costly component of health care for young patients with cardiac disease. Measurement of variation in their cost between hospitals and identification of the reasons for this variation may help reduce cost without compromising quality.

Methods and Results

Using data from Pediatric Health Information Systems Database from January 2007 to December 2015, the costs of 9 procedures were measured. Mixed‐effects multivariable models were used to generate case‐mix–adjusted estimates of each hospital's cost for each procedure and measure interhospital variation. Procedures (n=35 637) from 43 hospitals were studied. Median costs varied from $8249 (diagnostic catheterization after orthotopic heart transplantation) to $38 909 (transcatheter pulmonary valve replacement). There was marked variation in the cost of procedures between hospitals with 3.5‐ to 8.9‐fold differences in the case‐mix–adjusted cost between the most and least expensive hospitals. No significant correlation was found between hospitals’ procedure‐specific mortality rates and costs. Higher procedure volume was not associated with lower cost except for diagnostic procedures in heart transplant patients and pulmonary artery angioplasty. At the hospital level, the proportion of cases that were outliers (>95th percentile) was significantly associated with rank in terms of cost (Spearman's ρ ranging from 0.37 to 0.89, P<0.01).

Conclusions

Large‐magnitude hospital variation in cost was not explained by case‐mix or volume. Further research is necessary to determine the degree to which variation in cost is the result of differences in the efficiency of the delivery of healthcare services and the rate of catastrophic adverse outcomes and resultant protracted and expensive hospitalizations.

Resource Utilization in the First 2 Years Following Operative Correction for Tetralogy of Fallot: Study Using Data From the Optum's De-Identified Clinformatics Data Mart Insurance Claims Database

Background

Despite excellent operative survival, correction of tetralogy of Fallot frequently is accompanied by residual lesions that may affect health beyond the incident hospitalization. Measuring resource utilization, specifically cost and length of stay, provides an integrated measure of morbidity not appreciable in traditional outcomes.

Methods and Results

We conducted a retrospective cohort study, using de‐identified commercial insurance claims data, of 269 children who underwent operative correction of tetralogy of Fallot from January 2004 to September 2015 with ≥2 years of continuous follow‐up (1) to describe resource utilization for the incident hospitalization and subsequent 2 years, (2) to determine whether prolonged length of stay (>7 days) in the incident hospitalization was associated with increased subsequent resource utilization, and (3) to explore whether there was regional variation in resource utilization with both direct comparisons and multivariable models adjusting for known covariates. Subjects with prolonged incident hospitalization length of stay demonstrated greater resource utilization (total cost as well as counts of outpatient visits, hospitalizations, and catheterizations) after hospital discharge (P<0.0001 for each), though the number of subsequent operative and transcatheter interventions were not significantly different. Regional differences were observed in the cost of incident hospitalization as well as subsequent hospitalizations, outpatient visits, and the costs associated with each.

Conclusions

This study is the first to report short‐ and medium‐term resource utilization following tetralogy of Fallot operative correction. It also demonstrates that prolonged length of stay in the initial hospitalization is associated with increased subsequent resource utilization. This should motivate research to determine whether these differences are because of modifiable factors.

Variation in the use of pulmonary vasodilators in children and adolescents with pulmonary hypertension: a study using data from the MarketScan® insurance claims database

Despite progress in pharmacotherapy in pediatric pulmonary hypertension, real-world patterns of directed pulmonary hypertension therapy have not been studied in the current era. A retrospective observational study of children (≤18 years) with pulmonary hypertension was performed using data from the MarketScan® Commercial and Medicaid claims databases. Associations between etiology of pulmonary hypertension and pharmaceutical regimen were evaluated, as were the associations between subject social and geographic characteristics (insurance-type, race, and/or census region) and regimen. Annualized costs of single- and multi-class regimens were calculated. In total, 873 subjects were studied, of which 94% received phosphodiesterase-5 inhibitors, 31% endothelin receptor antagonist, 9% prostacyclin analogs, and 7% calcium channel blockers. Monotherapy was used in 72% of subjects. Phosphodiesterase-5 inhibitors monotherapy was the most common regimen (93%). Subjects with idiopathic pulmonary hypertension, congenital heart disease, and unclassified pulmonary hypertension receive more than one agent and were more likely to receive both endothelin receptor antagonist and prostacyclin analogs than other forms of pulmonary hypertension. Compared to recipients of public insurance, subjects with commercial insurance were more likely to receive more intense therapy (p = 0.003), which was confirmed in multivariable analysis (OR: 1.4, p = 0.03). Receipt of commercial insurance was also associated with increased annual costs across all subjects (p < 0.001) and for the most common specific regimens. The majority of children with pulmonary hypertension receive phosphodiesterase monotherapy, followed by phosphodiesterase–endothelin receptor antagonist two drug regimens, and finally the addition of prostacyclin analogs for three-drug therapy. However, even after adjustment for measurable confounders, commercial insurance was associated with higher intensity care and higher costs (even within specific classes of pulmonary vasodilators). The effect of these associations on clinical outcome cannot be discerned from the current data set, but patterns of treatment deserve further attention.

Use of Treprostinil in Pediatric Pulmonary Hypertension: Case Reports and Review of the Literature

BACKGROUND

Add-on therapy with prostacyclin in pediatric refractory pulmonary hypertension (PH) poses a challenge, especially when considering continuous intravenous administration in younger children. A search for alternate routes of drug delivery has led to the clinical investigation of stable and long-acting prostacyclin analogues, such as subcutaneous treprostinil. We reported 2 pediatric cases of PH treated with subcutaneous treprostinil and reviewed the literature on treprostinil use in children.

METHOD

The literature review used 3 electronic databases and a combination of terms (treprostinil, pediatric, PH, prostanoid, etc). We also searched for pediatric clinical trials on treprostinil registered on international clinical trial registries.

RESULTS

The reported cases highlighted the multifactorial nature of PH in pediatrics: a female child with a giant omphalocele, and intracardiac and extracardiac shunts; and a male premature child with a congenital diaphragmatic hernia and long-term PH. The literature review identified 19 studies reporting treprostinil use in 421 children with various types of PH (groups 1 and 3). Subcutaneous treprostinil was the most administered formulation, at a mean dose of 40 ng/kg/min. Overall, 12 clinical trials on treprostinil for children with PH were registered on the clinical trial registries. Most authors concluded that subcutaneous treprostinil was effective, well tolerated, and represented an alternative to intravenous epoprostenol.

CONCLUSIONS

Subcutaneous treprostinil may be a useful adjunct in the therapeutic algorithm for children with severe PH, refractory to oral drugs, and after a complete check-up for all PH etiologies.

Trends in transcatheter and operative closure of patent ductus arteriosus in neonatal intensive care units: Analysis of data from the Pediatric Health Information Systems Database

BACKGROUND

The risks and benefits of pharmacologic treatment and operative closure of patent ductus arteriosus (O-PDA) in premature infants remain controversial. Recent series have demonstrated the feasibility of transcatheter PDA closure (TC-PDA) in increasingly small infants. The effect of this change on practice has not been evaluated.

METHODS

A multicenter observational study of infants treated in neonatal intensive care units in hospitals contributing data to the Pediatric Health Information Systems Database from January 2007 to December 2017 was performed to study trends in the propensities for (1) mechanical closure of PDA and (2) TC-PDA versus O-PDA, as well as interhospital variation in practice.

RESULTS

A total of 6,214 subjects at 44 hospitals were studied (5% TC-PDA). Subject median gestational age was 25 weeks (interquartile range: 24-27 weeks). Median age at closure was 24 days (interquartile range: 14-36 days). The proportion of all neonatal intensive care unit patients undergoing either O-PDA or TC-PDA decreased (3.1% in 2007 and 0.7% in 2017, P < .001), whereas the proportion in which TC-PDA was used increased significantly (0.1% in 2007 to 29.0% in 2017). Case-mix-adjusted multivariable models similarly demonstrated increasing propensity to pursue TC-PDA (odds ratio [OR] 1.66 per year, P < .001) with acceleration of the trend after 2014 (OR 2.46 per year, P < .001) as well as significant practice variation (P < .001, median OR 4.6) across the study period.

CONCLUSIONS

In the face of decreasing closure of PDA, the use of TC-PDA increased dramatically with significant practice variability. This demonstrates that there is equipoise for potential clinical trials.

Failure to Rescue as an Outcome Metric for Pediatric and Congenital Cardiac Catheterization Laboratory Programs: Analysis of Data From the IMPACT Registry

Background

Risk‐adjusted adverse event (AE) rates have been used to measure the quality of pediatric and congenital cardiac catheterization laboratories. In other settings, failure to rescue (FTR) has demonstrated utility as a quality metric.

Methods and Results

A multicenter retrospective cohort study was performed using data from the IMPACT (Improving Adult and Congenital Treatment) Registry between January 2010 and December 2016. A modified FTR metric was developed for pediatric and congenital cardiac catheterization laboratories and then compared with pooled AEs. The associations between patient‐ and hospital‐level factors and outcomes were evaluated using hierarchical logistic regression models. Hospital risk standardized ratios were then calculated. Rankings of risk standardized ratios for each outcome were compared to determine whether AEs and FTR identified the same high‐ and low‐performing centers. During the study period, 77 580 catheterizations were performed at 91 hospitals. Higher annual hospital catheterization volume was associated with lower odds of FTR (odds ratio: 0.68 per 300 cases; P=0.0003). No association was seen between catheterization volume and odds of AEs. Odds of AEs were instead associated with patient‐ and procedure‐level factors. There was no correlation between risk standardized ratio ranks for FTR and pooled AEs (P=0.46). Hospital ranks by catheterization volume and FTR were associated (r=−0.28, P=0.01) with the largest volume hospitals having the lowest risk of FTR.

Conclusions

In contrast to AEs, FTR was not strongly associated with patient‐ and procedure‐level factors and was significantly associated with pediatric and congenital cardiac catheterization laboratory volume. Hospital rankings based on FTR and AEs were not significantly correlated. We conclude that FTR is a complementary measure of catheterization laboratory quality and should be included in future research and quality‐improvement projects.

Association Between Variation in Preoperative Care Before Arterial Switch Operation and Outcomes in Patients With Transposition of the Great Arteries

BACKGROUND

The arterial switch operation (ASO) is the gold standard operative correction of neonates with transposition of the great arteries and intact ventricular septum, with excellent operative survival. The associations between patient and surgeon characteristics and outcomes are well understood, but the associations between variation in preoperative care and outcomes are less well studied.

METHODS

A multicenter retrospective cohort study of infants undergoing neonatal ASO between January 2010 and September 2015 at hospitals contributing data to the Pediatric Health Information Systems database was performed. The association between preoperative care (timing of ASO, preoperative use of balloon atrial septostomy, prostaglandin infusion, mechanical ventilation, and vasoactive agents) and operative outcomes (mortality, length of stay, and cost) was studied with multivariable mixed-effects models.

RESULTS

Over the study period, 2159 neonates at 40 hospitals were evaluated. Perioperative mortality was 2.8%. Between hospitals, the use of adjuvant therapies and timing of ASO varied broadly. At the subject level, older age at ASO was associated with higher mortality risk (age >6 days: odds ratio, 1.90; 95% CI, 1.11-3.26; P=0.02), cost, and length of stay. Receipt of a balloon atrial septostomy was associated with lower mortality risk (odds ratio, 0.32; 95% CI, 0.17-0.59; P<0.001), cost, and length of stay. Later hospital median age at ASO was associated with higher odds of mortality (odds ratio, 1.15 per day; 95% CI, 1.02-1.29; P=0.03), longer length of stay ( P<0.004), and higher cost ( P<0.001). Other hospital factors were not independently associated with the outcomes of interest.

CONCLUSIONS

There was significant variation in preoperative care between hospitals. Some potentially modifiable aspects of perioperative care (timing of ASO and septostomy) were significantly associated with mortality, length of stay, and cost. Further research on the perioperative care of neonates is necessary to determine whether modifying practice on the basis of the observed associations translates into improved outcomes.

Relationship between pulmonary artery acceleration time and pulmonary artery pressures in infants

BACKGROUND

Pulmonary artery acceleration time measured by echocardiography inversely correlates with pulmonary artery pressures in adults and children older than 1 year of age. There is a paucity of data investigating this relationship in young children, particularly among preterm infants.

OBJECTIVE

To characterize the relationship between pulmonary artery acceleration time (PAAT) and pulmonary artery pressures in infants.

DESIGN/METHODS

Patients ≤ 1 year of age at Children's Hospital of Philadelphia between 2011 and 2017 were reviewed. Infants with congenital heart disease were excluded, except those with a patent ductus arteriosus (PDA), atrial septal defect (ASD), or ventricular septal defect (VSD). Linear regression analysis was used to assess the correlation between PAAT measured by echocardiography and systolic pulmonary artery pressure, mean pulmonary artery pressure, and indexed pulmonary vascular resistance from cardiac catheterization.

RESULTS

Fifty-seven infants were included, of which 61% were preterm and 49% had a diagnosis of bronchopulmonary dysplasia. The median postmenstrual age and weight at catheterization were 51.1 weeks (IQR 35.8-67.9 weeks) and 4400 g (IQR 3100-6500 g), respectively. Forty-four infants (77%) had a patent ductus arteriosus (PDA). There was a weak inverse correlation between PAAT with mPAP (r = -0.35, P = 0.01), sPAP (r = -0.29, P = 0.03), and PVRi (r = -0.29, P = 0.03).

CONCLUSION

There is a weak inverse relationship between PAAT and pulmonary artery pressures. This relationship is less robust in our population of infants with a high incidence of PDAs compared to previous studies in older children. Thus, PAAT may be less clinically meaningful for diagnosing pulmonary arterial hypertension in infants, particularly those with PDAs.

Right ventricular-vascular coupling ratio in pediatric pulmonary arterial hypertension: A comparison between cardiac magnetic resonance and right heart catheterization measurements

BACKGROUND

In pulmonary arterial hypertension (PAH), right ventricular (RV) failure is the main cause of mortality. Non-invasive estimation of ventricular-vascular coupling ratio (VVCR), describing contractile response to afterload, could be a valuable tool for monitoring clinical course in children with PAH. This study aimed to test two hypotheses: VVCR by cardiac magnetic resonance (VVCR_CMR) correlates with conventional VVCR by right heart catheterization (VVCR_RHC) and both correlate with disease severity.

METHODS AND RESULTS

Twenty-seven patients diagnosed with idiopathic and associated PAH without post-tricuspid shunt, who underwent RHC and CMR within 17 days at two specialized centers for pediatric PAH were retrospectively studied. Clinical functional status and hemodynamic data were collected. Median age at time of MRI was 14.3 years (IQR: 11.1-16.8), median PVRi 7.6 WU × m² (IQR: 4.1-12.2), median mPAP 40 mm Hg (IQR: 28-55) and median WHO-FC 2 (IQR: 2-3). VVCR_CMR, defined as stroke volume/end-systolic volume ratio was compared to VVCR_RHC by single-beat pressure method using correlation and Bland-Altman plots. VVCR_CMR and VVCR_RHC showed a strong correlation (r = 0.83, p < 0.001). VVCR_CMR and VVCR_RHC both correlated with clinical measures of disease severity (pulmonary vascular resistance index [PVRi], mean pulmonary artery pressure [mPAP], mean right atrial pressure [mRAP], and World Health Organization functional class [WHO-FC]; all p ≤ 0.02).

CONCLUSIONS

Non-invasively measured VVCR_CMR is feasible in pediatric PAH and comparable to invasively assessed VVCR_RHC. Both correlate with functional and hemodynamic measures of disease severity. The role of VVCR assessed by CMR and RHC in clinical decision-making and follow-up in pediatric PAH warrants further clinical investigation.

Current understanding and perioperative management of pediatric pulmonary hypertension

Pediatric pulmonary hypertension is a complex disease with multiple, diverse etiologies affecting the premature neonate to the young adult. Pediatric pulmonary arterial hypertension, whether idiopathic or associated with congenital heart disease, is the most commonly discussed form of pediatric pulmonary hypertension, as it is progressive and lethal. However, neonatal forms of pulmonary hypertension are vastly more frequent, and while most cases are transient, the risk of morbidity and mortality in this group deserves recognition. Pulmonary hypertension due to left heart disease is another subset increasingly recognized as an important cause of pediatric pulmonary hypertension. One aspect of pediatric pulmonary hypertension is very clear: anesthetizing the child with pulmonary hypertension is associated with a significantly heightened risk of morbidity and mortality. It is therefore imperative that anesthesiologists who care for children with pulmonary hypertension have a firm understanding of the pathophysiology of the various forms of pediatric pulmonary hypertension, the impact of anesthesia and sedation in the setting of pulmonary hypertension, and anesthesiologists' role as perioperative experts from preoperative planning to postoperative disposition. This review summarizes the current understanding of pediatric pulmonary hypertension physiology, preoperative risk stratification, anesthetic risk, and intraoperative considerations relevant to the underlying pathophysiology of various forms of pediatric pulmonary hypertension.

Acute Vasoreactivity Testing during Cardiac Catheterization of Neonates with Bronchopulmonary Dysplasia-Associated Pulmonary Hypertension

OBJECTIVES

To assess whether better baseline pulmonary hemodynamics or positive acute vasoreactivity testing (AVT) during cardiac catheterization are associated with improved outcomes in infants with bronchopulmonary dysplasia (BPD) and pulmonary hypertension (PH).

STUDY DESIGN

This retrospective, single-center study included 26 premature neonates with BPD who underwent catheterization to evaluate PH. AVT was assessed with exposure to 100% fractional inspired oxygen with or without inhaled nitric oxide. AVT was positive if the patient met the Barst criteria or increased shunt volume and decreased pulmonary vascular resistance index by >50%.

RESULTS

At baseline, the median pulmonary artery mean pressure was 29 mm Hg (IQR, 24-35) and the pulmonary vascular resistance index was 5.3 units*m² (IQR, 3.5-6.9). Nine patients (35%) had a positive AVT response, which was associated with a decreased risk of death or tracheostomy by 2-year follow-up (hazard ratio, 0.15; P = .02). Baseline pulmonary hemodynamics and the presence of left ventricular diastolic dysfunction were not associated with late outcomes in this cohort.

CONCLUSIONS

We found that 35% of infants with BPD who underwent catheterization had positive AVT and that a positive response was associated with better long-term outcomes than nonresponders. AVT better distinguishes higher from lower risk PH in infants with BPD than baseline pulmonary hemodynamics. AVT may aid in the assessment of disease severity and management of BPD-associated PH.

Risk Factors for Major Early Adverse Events Related to Cardiac Catheterization in Children and Young Adults With Pulmonary Hypertension: An Analysis of Data From the IMPACT (Improving Adult and Congenital Treatment) Registry

BACKGROUND

Cardiac catheterization is the gold standard for assessment and follow-up of patients with pulmonary hypertension (PH). To date, there are limited data about the factors that influence the risk of catastrophic adverse events after catheterization in this population.

METHODS AND RESULTS

A retrospective multicenter cohort study was performed to measure risk of catastrophic adverse outcomes after catheterization in children and young adults with PH and identify risk factors for these outcomes. All catheterizations in children and young adults, aged 0 to 21 years, with PH at hospitals submitting data to the IMPACT (Improving Adult and Congenital Treatment) registry between January 1, 2011, and December 31, 2015, were studied. Using mixed-effects multivariable regression, we assessed the association between prespecified subject-, procedure-, and center-level covariates and the risk of death, cardiac arrest, or mechanical circulatory support during or after cardiac catheterization. A total of 8111 procedures performed in 7729 subjects at 77 centers were studied. The observed risk of the composite outcome was 1.4%, and the risk of death before discharge was 5.2%. Catheterization in prematurely born neonates and nonpremature infants was associated with increased risk of catastrophic adverse event, as was precatheterization treatment with inotropes and lower systemic arterial saturation. Secondary analyses demonstrated the following: (1) increasing volumes of catheterization in patients with PH were associated with reduced risk of composite outcome (odds ratio, 0.8 per 10 procedures; P=0.002) and (2) increasing pulmonary vascular resistance and pulmonary artery pressures were associated with increased risk (P<0.0001 for both).

CONCLUSIONS

Young patients with PH are a high-risk population for diagnostic and interventional cardiac catheterization. Hospital experience with PH is associated with reduced risk, independent of total catheterization case volume.

Right ventricular function mirrors clinical improvement with use of prostacyclin analogues in pediatric pulmonary hypertension

Pulmonary hypertension (PH) causes significant morbidity and mortality in children due to right ventricular (RV) failure. We sought to determine the effect of prostacyclin analogues on RV function assessed by echocardiography in children with PH. We conducted a retrospective cohort study of children with PH treated with a prostacyclin analogue (epoprostenol or treprostinil) between January 2001 and August 2015 at our center. Data were collected before initiation of treatment (baseline) and at 1–3 and 6–12 months after. Protocolized echocardiogram measurements including tricuspid annular plane systolic excursion (TAPSE) and RV global longitudinal strain were made with blinding to clinical information. Forty-nine individuals (65% female), aged 0–29 years at the time of prostacyclin initiation were included. Disease types included pulmonary arterial hypertension (idiopathic [35%], heritable [2%], and congenital heart disease-associated [18%]), developmental lung disease (43%), and chronic thromboembolic PH (2%). Participants received intravenous (IV) epoprostenol (14%) and IV/subcutaneous (SQ) (67%) or inhaled (18%) treprostinil. Over the study period, prostacyclin analogues were associated with improvement in TAPSE (P = 0.007), RV strain (P < 0.001), and qualitative RV function (P = 0.037) by echocardiogram, and BNP (P < 0.001), functional class (P = 0.047) and 6-min walk distance (P = 0.001). TAPSE and strain improved at early follow up (P = 0.05 and P = 0.002, respectively) despite minimal RV pressure change. In children with PH, prostacyclin analogues are associated with an early and sustained improvement in RV function measured as TAPSE and strain as well as clinical markers of PH severity. RV strain may be a sensitive marker of RV function in this population.

Perioperative events in children with pulmonary hypertension undergoing non-cardiac procedures

Prior limited research indicates that children with pulmonary hypertension (PH) have higher rates of adverse perioperative outcomes when undergoing non-cardiac procedures and cardiac catheterizations. We examined a single-center retrospective cohort of children with active or pharmacologically controlled PH who underwent cardiac catheterization or non-cardiac surgery during 2006–2014. Preoperative characteristics and perioperative courses were examined to determine relationships between the severity or etiology of PH, type of procedure, and occurrence of major and minor events. We identified 77 patients who underwent 148 procedures at a median age of six months. The most common PH etiologies were bronchopulmonary dysplasia (46.7%), congenital heart disease (29.9%), and congenital diaphragmatic hernia (14.3%). Cardiac catheterizations (39.2%), and abdominal (29.1%) and central venous access (8.9%) were the most common procedures. Major events included failed planned extubation (5.6%), postoperative cardiac arrest (4.7%), induction or intraoperative cardiac arrest (2%), and postoperative death (1.4%). Major events were more frequent in patients with severe baseline PH (P = 0.006) and the incidence was associated with procedure type (P = 0.05). Preoperative inhaled nitric oxide and prostacyclin analog therapies were associated with decreased incidence of minor events (odds ratio [OR] = 0.32, P = 0.046 and OR = 0.24, P = 0.008, respectively), but no change in the incidence of major events. PH etiology was not associated with events (P = 0.24). Children with PH have increased risk of perioperative complications; cardiac arrest and death occur more frequently in patients with severe PH and those undergoing thoracic procedures. Risk may be modified by using preoperative pulmonary vasodilator therapy and lends itself to further prospective studies.

Increasing propensity to pursue operative closure of atrial septal defects following changes in the instructions for use of the Amplatzer Septal Occluder device: An observational study using data from the Pediatric Health Information Systems database

Concern for device erosion following transcatheter treatment of atrial septal defects (TC-ASD) led in 2012 to a United States Food and Drug Administration panel review and changes in the instructions for use of the Amplatzer Septal Occluder (ASO) device. No studies have assessed the effect of these changes on real-world practice. To this end a multicenter observational study was performed to evaluate trends in the treatment of ASD.

METHODS

A retrospective observational study was performed using data from the Pediatric Health Information Systems database of all patients with isolated ASD undergoing either TC-ASD or operative ASD closure (O-ASD) from January 1, 2007, to September 30, 2015, hypothesizing that the propensity to pursue O-ASD increased beginning in 2013.

RESULTS

A total of 6,392 cases from 39 centers underwent ASD closure (82% TC-ASD). Adjusting for patient factors, between 2007 and 2012, the probability of pursuing O-ASD decreased (odds ratio [OR] 0.95 per year, P = .03). This trend reversed beginning in 2013, with the probability of O-ASD increasing annually (OR 1.21, P = .006). There was significant between-hospital variation in the choice between TC-ASD and O-ASD (median OR 2.79, P < .0001). The age of patients undergoing ASD closure (regardless of method) decreased over the study period (P = .04). Cost of O-ASD increased over the study period, whereas cost of TC-ASD and length of stay for both O-ASD and TC-ASD was unchanged.

CONCLUSIONS

Although TC-ASD remains the predominant method of ASD closure, the propensity to pursue O-ASD has increased significantly following changes in instructions for use for ASO. Further research is necessary to determine what effect this has on outcomes and resource utilization.

Diagnostic Approach to Pulmonary Hypertension in Premature Neonates

Bronchopulmonary dysplasia (BPD) is a form of chronic lung disease in premature infants following respiratory distress at birth. With increasing survival of extremely low birth weight infants, alveolar simplification is the defining lung characteristic of infants with BPD, and along with pulmonary hypertension, increasingly contributes to both respiratory morbidity and mortality in these infants. Growth restricted infants, infants born to mothers with oligohydramnios or following prolonged preterm rupture of membranes are at particular risk for early onset pulmonary hypertension. Altered vascular and alveolar growth particularly in canalicular and early saccular stages of lung development following mechanical ventilation and oxygen therapy, results in developmental lung arrest leading to BPD with pulmonary hypertension (PH). Early recognition of PH in infants with risk factors is important for optimal management of these infants. Screening tools for early diagnosis of PH are evolving; however, echocardiography is the mainstay for non-invasive diagnosis of PH in infants. Cardiac computed tomography (CT) and magnetic resonance are being used as imaging modalities, however their role in improving outcomes in these patients is uncertain. Follow-up of infants at risk for PH will help not only in early diagnosis, but also in appropriate management of these infants. Aggressive management of lung disease, avoidance of hypoxemic episodes, and optimal nutrition determine the progression of PH, as epigenetic factors may have significant effects, particularly in growth-restricted infants. Infants with diagnosis of PH are managed with pulmonary vasodilators and those resistant to therapy need to be worked up for the presence of cardio-vascular anomalies. The management of infants and toddlers with PH, especially following premature birth is an emerging field. Nonetheless, combination therapies in a multi-disciplinary setting improves outcomes for these infants.

Hepatoma-derived Growth Factor Predicts Disease Severity and Survival in Pulmonary Arterial Hypertension

RATIONALE

Pulmonary arterial hypertension (PAH) is a fatal disease, and pulmonary microvascular remodeling is an important contributor to PAH development. Therefore, we hypothesized that a circulating angiogenic factor could predict disease severity and survival.

OBJECTIVES

We sought to assess the relationship of serum hepatoma-derived growth factor (HDGF) with PAH disease severity and survival.

METHODS

Using a newly developed enzyme-linked immunosorbent assay, we evaluated circulating HDGF levels in two independent PAH cohorts and two different characterized control cohorts. Clinical and laboratory data were also used to assess the value of HDGF as a PAH prognostic biomarker.

MEASUREMENTS AND MAIN RESULTS

Serum HDGF levels were significantly elevated in two independent PAH cohorts. Importantly, serum HDGF levels were not elevated in a noncardiac chronic disease cohort. Further, patients with elevated HDGF had significantly lower exercise tolerance, worse New York Heart Association functional class, and higher levels of N-terminal pro-brain natriuretic peptide. HDGF was a strong predictor of mortality, with an unadjusted hazard ratio of 4.5 (95% confidence interval, 1.9-10.3; P = 0.003 by log-rank test). In multivariable Cox proportional hazards models, elevated HDGF levels predicted decreased survival after being adjusted for age, PAH subtype, invasive hemodynamics, and N-terminal pro-brain natriuretic peptide.

CONCLUSIONS

Elevated HDGF was associated with worse functional class, exertional intolerance, and increased mortality in PAH, suggesting HDGF as a potential biomarker for predicting mortality and as having possible diagnostic value for distinguishing PAH from non-PAH. HDGF may add additional value in PAH risk stratification in clinical trials and may represent a potential target for future PAH drug development.

Diagnostics in Children and Adolescents with Suspected or Confirmed Pulmonary Hypertension

We provide a practical approach on the initial assessment and diagnostic work-up of children and adolescents with pulmonary hypertension (PH). Transthoracic echocardiography (TTE) often serves as initial study tool before invasive cardiac catheterization. Misinterpretation of TTE variables may lead to missed or delayed diagnosis with devastating consequences, or unnecessary invasive diagnostics that have inherited risks. In addition to clinical and biochemical markers, serial examination of patients with PH using a standardized TTE approach, determining conventional and novel echocardiographic variables, may allow early diagnosis and treatment in paediatric PH. Cardiac magnetic resonance imaging and computed tomography represent important non-invasive imaging modalities, that together with TTE may enable comprehensive assessment of ventricular function and pulmonary hemodynamics. Invasive assessment of haemodynamics (ventricular, pulmonary) and testing of acute vasoreactivity in the catheterization laboratory is still the gold standard for the diagnosis of PH and pulmonary hypertensive vascular disease (PHVD) in children and for the initiation of specific PH therapy. We suggest the regular assessment of prognostic TTE variables as part of a standardized approach for initial diagnosis of children with PH. Overreliance on any single TTE variable should be avoided as it detracts from the overall diagnostic potential of a standardized TTE examination for PH.

Acoustic diagnosis of pulmonary hypertension: automated speech- recognition-inspired classification algorithm outperforms physicians

We hypothesized that an automated speech- recognition-inspired classification algorithm could differentiate between the heart sounds in subjects with and without pulmonary hypertension (PH) and outperform physicians. Heart sounds, electrocardiograms, and mean pulmonary artery pressures (mPAp) were recorded simultaneously. Heart sound recordings were digitized to train and test speech-recognition-inspired classification algorithms. We used mel-frequency cepstral coefficients to extract features from the heart sounds. Gaussian-mixture models classified the features as PH (mPAp ≥ 25 mmHg) or normal (mPAp < 25 mmHg). Physicians blinded to patient data listened to the same heart sound recordings and attempted a diagnosis. We studied 164 subjects: 86 with mPAp ≥ 25 mmHg (mPAp 41 ± 12 mmHg) and 78 with mPAp < 25 mmHg (mPAp 17 ± 5 mmHg) (p  < 0.005). The correct diagnostic rate of the automated speech-recognition-inspired algorithm was 74% compared to 56% by physicians (p = 0.005). The false positive rate for the algorithm was 34% versus 50% (p = 0.04) for clinicians. The false negative rate for the algorithm was 23% and 68% (p = 0.0002) for physicians. We developed an automated speech-recognition-inspired classification algorithm for the acoustic diagnosis of PH that outperforms physicians that could be used to screen for PH and encourage earlier specialist referral.

Cardiac catheterization in children with pulmonary hypertensive vascular disease: consensus statement from the Pulmonary Vascular Research Institute, Pediatric and Congenital Heart Disease Task Forces

Cardiac catheterization is important in the diagnosis and risk stratification of pulmonary hypertensive vascular disease (PHVD) in children. Acute vasoreactivity testing provides key information about management, prognosis, therapeutic strategies, and efficacy. Data obtained at cardiac catheterization continue to play an important role in determining the surgical options for children with congenital heart disease and clinical evidence of increased pulmonary vascular resistance. The Pediatric and Congenital Heart Disease Task Forces of the Pulmonary Vascular Research Institute met to develop a consensus statement regarding indications for, conduct of, acute vasoreactivity testing with, and pitfalls and risks of cardiac catheterization in children with PHVD. This document contains the essentials of those discussions to provide a rationale for the hemodynamic assessment by cardiac catheterization of children with PHVD.

Changes in Ventricular Geometry Predict Severity of Right Ventricular Hypertension

Changes in ventricular geometry are often seen in patients with right ventricular hypertension secondary to pulmonary hypertension (PH). Progressive systolic bowing of the inter-ventricular septum occurs with increasing right ventricular pressure (RVp) and can be quantified with the left ventricular end-systolic eccentricity index (LVEI). Only limited data exist in children to evaluate the relationship between the LVEI and invasive RVp. We sought to assess the correlation between the LVEI and an invasively measured peak systolic RVp to aortic pressure (pAo) ratio. Medical records of patients undergoing echocardiography within 30 days of right and left heart catheterization for evaluation of PH between February 2009 and March 2014 were retrospectively reviewed. Forty-six studies in 29 subjects (median age 3.8 years, 46 % female), with a median time from echocardiogram to catheterization of -1.0 days, were included for analysis. The mean LVEI was 1.6 ± 0.5, and mean RVp/pAo ratio was 0.68 ± 0.26. There was a significant positive correlation (r = 0.76, p < 0.001) between LVEI and RVp/pAo ratio. ROC analysis demonstrated an area under the curve = 0.91 for prediction of RVp/pAo >0.50 by the LVEI. An LVEI >1.48 had a sensitivity of 76 % and specificity of 100 % in predicting RVp/pAo >0.50, while an LVEI >1.24 had a sensitivity of 88 % and specificity of 83 %. Echocardiographically derived LVEI is strongly correlated with invasively determined RVp/pAo ratio. In combination with other noninvasive measures of RVp, LVEI may help minimize the need for invasive patient evaluation.