Trends in pediatric pulmonary hypertension-related hospitalizations in the United States from 2000-2009

Stress hyperglycemia is associated with poor outcome in critically ill patients with pulmonary hypertension

Background and objective

Stress hyperglycemia is common in critically ill patients and is associated with poor prognosis. Whether this association exists in pulmonary hypertension (PH) patients is unknown. The present cohort study investigated the association of stress hyperglycemia with 90-day all-cause mortality in intensive care unit (ICU) patients with PH.

Methods

Data of the study population were extracted from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. A new index, the ratio of admission glucose to HbA1c (GAR), was used to evaluate stress hyperglycemia. The study population was divided into groups according to GAR quartiles (Q1-Q4). The outcome of interest was all-cause mortality within 90 days, which was considered a short-term prognosis.

Result

A total of 53,569 patients were screened. Ultimately, 414 PH patients were enrolled; 44.2% were male, and 23.2% were admitted to the cardiac ICU. As the GAR increased from Q2 to Q4, the groups had lower creatinine levels, longer ICU stays, and a higher proportion of renal disease. After adjusting for confounding factors such as demographics, vital signs, and comorbidities, an elevated GAR was associated with an increased risk of 90-day mortality.

Conclusion

Stress hyperglycemia assessed by the GAR was associated with increased 90-day mortality in ICU patients with PH.

Lung Transplantation for Pulmonary Vascular Disease in Children: A United Network for Organ Sharing Analysis

Pulmonary vascular disease (PVD) represents an important clinical indication for lung transplant (LTx) in infants, children, and adolescents. There is limited information on LTx outcomes in these patients. We explored LTx volumes and post-LTx survival in children with PVD compared to other diagnoses. The UNOS Registry was queried from 1989 to 2020 to identify first-time pediatric LTx recipients (< 18 yo). PVD was categorized as idiopathic pulmonary arterial hypertension (IPAH) and non-idiopathic arterial hypertension (non-IPAH) and compared to all other patients as other diagnoses. Univariate and multivariate regression models were performed. 984 pediatric LTx patients (593 before 2010 and 391 during/after 2010) were identified, of which 145 (14.7%) had PVD. There has been no significant change in annual rate of all LTxs over comparative eras. However, there has been a decrease in rate of LTxs for PVD patients. Children with PVD had similar survival to other LTx groups in the early era (p = 0.2) and the latter era (p = 0.9). Univariate Cox models, showed that LTx in patients with PVD was associated with a significantly less risk of mortality for children aged 6-11 years compared to younger and older cohorts (HR = 0.4 [0.17-0.98]; p = 0.045), whereas multivariate analysis showed a trend toward higher mortality in 11-17-year-olds (HR = 1.54 [0.97-2.45]; p = 0.06). For PVD patients, oxygen supplementation and ventilator support at LTx were associated with worse post-transplant survival (p = 0.029 and p = 0.01). There has been a decrease in LTx volume for pediatric patients with PVD in the modern era. Post-LTx outcomes for children with PVD are similar to those of other diagnoses in both eras, with children aged 6-11 years having the best survival. Given these findings, LTx should be considered for this patient population.

A Review of Serotonin in the Developing Lung and Neonatal Pulmonary Hypertension

Serotonin (5-HT) is a bioamine that has been implicated in the pathogenesis of pulmonary hypertension (PH). The lung serves as an important site of 5-HT synthesis, uptake, and metabolism with signaling primarily regulated by tryptophan hydroxylase (TPH), the 5-HT transporter (SERT), and numerous unique 5-HT receptors. The 5-HT hypothesis of PH was first proposed in the 1960s and, since that time, preclinical and clinical studies have worked to elucidate the role of 5-HT in adult PH. Over the past several decades, accumulating evidence from both clinical and preclinical studies has suggested that the 5-HT signaling pathway may play an important role in neonatal cardiopulmonary transition and the development of PH in newborns. The expression of TPH, SERT, and the 5-HT receptors is developmentally regulated, with alterations resulting in pulmonary vasoconstriction and pulmonary vascular remodeling. However, much remains unknown about the role of 5-HT in the developing and newborn lung. The purpose of this review is to discuss the implications of 5-HT on fetal and neonatal pulmonary circulation and summarize the existing preclinical and clinical literature on 5-HT in neonatal PH.

Lung Transplantation for Pulmonary Vascular Disease in Children: A United Network for Organ Sharing Analysis

Background

Pulmonary vascular disease (PVD) represents an important clinical indication for lung transplant (LTx) in infants, children, and adolescents. There is limited information on LTx outcomes in these patients. We explored LTx volumes and post-LTx survival in children with PVD compared to other diagnoses.

Methods

The UNOS Registry was queried from 1989-2020 to identify first-time pediatric LTx recipients (<18 yo). PVD was categorized as idiopathic pulmonary arterial hypertension (IPAH) and non-idiopathic arterial hypertension (non-IPAH) and compared to all other patients as other diagnoses. Univariate and multivariate regression models were performed.

Results

984 pediatric LTx patients (593 before 2010 and 391 during/after 2010) were identified, of which 145 (14.7%) had PVD. There has been no significant change in annual rate of all LTxs over comparative eras. However, there has been a decrease in rate of LTxs for PVD patients. Children with PVD had similar survival to other LTx groups in the early era (p=0.2) and the latter era (p=0.9). Univariate Cox models, showed that LTx in patients with PVD was associated with a significantly less risk of mortality for children aged 6-11 years compared to younger and older cohorts (HR=0.4 [0.17-0.98];p=0.045), whereas multivariate analysis showed a trend towards higher mortality in 11-17-year-olds (HR=1.54 [0.97-2.45];p=0.06). For PVD patients, oxygen supplementation and ventilator support at LTx were associated with worse post-transplant survival (p=0.029 and p=0.01).

Conclusions

There has been a decrease in LTx volume for pediatric patients with PVD in the modern era. Post-LTx outcomes for children with PVD are similar to those of other diagnoses in both eras, with children aged 6-11 years having the best survival. Given these findings, LTx should be considered for this patient population.

Outcomes for Children With Pulmonary Hypertension Undergoing Tracheostomy Placement: A Multi-Institutional Analysis

OBJECTIVES

To describe epidemiology, interventions, outcomes, and the health services experience for a cohort of children with pulmonary hypertension (PH) who underwent tracheostomy placement and to identify risk factors for inhospital mortality and 30-day readmissions.

DESIGN

Retrospective cohort study of the Pediatric Health Information System database.

SETTING

Thirty-seven freestanding U.S. children's hospitals.

PATIENTS

Patients 31 days to 21 years old who were discharged from the hospital between January 1, 2009, and December 31, 2017, with a diagnosis of primary or secondary PH, and who underwent tracheostomy placement. Outcomes were examined over a 2-year period from the time of discharge from the index encounter.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

There were 793 patients with PH who underwent tracheostomy placement. The overall inhospital mortality rate was 23.7%. Secondary PH due to congenital heart disease (CHD) was significantly associated with overall inhospital mortality (adjusted odds ratio [OR], 2.36; 95% CI, 1.38-4.04). The rate of 30-day readmissions for patients over the 2-year follow-up period was 33.3%. Tracheostomy during the index encounter and the diagnosis of secondary PH due to CHD were significantly associated with lower rates of 30-day readmissions (adjusted OR, 0.34; 95% CI, 0.19-0.61; and adjusted OR, 0.43; 95% CI, 0.24-0.77, respectively).

CONCLUSIONS

In the context of expanding utilization of tracheostomy and long-term ventilation, children with PH are among the highest risk cohorts for extended and repeated hospitalization and death. Tracheostomy placement during the index encounter was associated with fewer 30-day readmissions over the 2-year follow-up period. Further understanding of which subgroups may benefit from earlier intervention and which subgroups are at highest risk may offer important clinical insight when considering optimal timing of tracheostomy and may enhance informed decision-making for all stakeholders.

Explainable machine learning models for predicting 30-day readmission in pediatric pulmonary hypertension: A multicenter, retrospective study

Background

Short-term readmission for pediatric pulmonary hypertension (PH) is associated with a substantial social and personal burden. However, tools to predict individualized readmission risk are lacking. This study aimed to develop machine learning models to predict 30-day unplanned readmission in children with PH.

Methods

This study collected data on pediatric inpatients with PH from the Chongqing Medical University Medical Data Platform from January 2012 to January 2019. Key clinical variables were selected by the least absolute shrinkage and the selection operator. Prediction models were selected from 15 machine learning algorithms with excellent performance, which was evaluated by area under the operating characteristic curve (AUC). The outcome of the predictive model was interpreted by SHapley Additive exPlanations (SHAP).

Results

A total of 5,913 pediatric patients with PH were included in the final cohort. The CatBoost model was selected as the predictive model with the greatest AUC for 0.81 (95% CI: 0.77–0.86), high accuracy for 0.74 (95% CI: 0.72–0.76), sensitivity 0.78 (95% CI: 0.69–0.87), and specificity 0.74 (95% CI: 0.72–0.76). Age, length of stay (LOS), congenital heart surgery, and nonmedical order discharge showed the greatest impact on 30-day readmission in pediatric PH, according to SHAP results.

Conclusions

This study developed a CatBoost model to predict the risk of unplanned 30-day readmission in pediatric patients with PH, which showed more significant performance compared with traditional logistic regression. We found that age, LOS, congenital heart surgery, and nonmedical order discharge were important factors for 30-day readmission in pediatric PH.

Demographics and Risk Factors of Pediatric Pulmonary Hypertension Readmissions

BACKGROUND AND OBJECTIVES

Pulmonary hypertension (PH) leads to significant morbidity and mortality in pediatric patients and increases the readmission rates for hospitalizations. This study evaluates the risk factors and comorbidities associated with an increase in 30-day readmissions among pediatric PH patients.

METHODS

National Readmission Database (NRD) 2017 was searched for patients less than 18 years of age who were diagnosed with PH based on the International Classification of Diseases, 10th Revision (ICD-10). Statistical Package for the Social Sciences (SPSS) software v25.0 (IBM Corp., Armonk, NY) was used for statistical analysis.

RESULTS

Of 5.52 million pediatric encounters, 10,501 patients met the selection criteria. The 30-day readmission rate of 14.43% (p < 0.001) was higher than hospitalizations from other causes {Odds Ratio (OR) 4.02 (3.84-4.20), p < 0.001}. The comorbidities of sepsis {OR 0.75 (0.64-0.89), p < 0.02} and respiratory infections {OR 0.75 (0.67-0.85), p < 0.001} were observed to be associated with lower 30-day readmissions. Patients who required invasive mechanical ventilation via endotracheal tube {OR 1.66 (1.4-1.96), p < 0.001} or tracheostomy tube {OR 1.35 (1.15-1.6), p < 0.001} had increased unplanned readmissions. Patients with higher severity of illness based on All Patients Refined Diagnosis Related Groups (APR-DRG) were more likely to get readmitted {OR 7.66 (3.13-18.76), p < 0.001}.

CONCLUSION

PH was associated with increased readmission rates compared to the other pediatric diagnoses, but the readmission rate in this study was lower than one previous pediatric study. Invasive mechanical ventilation, Medicaid insurance, higher severity of illness, and female gender were associated with a higher likelihood of readmission within 30 days.

Mortality from Pulmonary Hypertension in the Pediatric Cardiac ICU

Rationale: Patients with pulmonary hypertension (PH) admitted to pediatric cardiac ICUs are at high risk of mortality. Objectives: To identify factors associated with mortality in cardiac critical care admissions with PH. Methods: We evaluated medical admissions with PH to Pediatric Cardiac Critical Care Consortium institutions over 5 years. PH was standardly defined in the clinical registry by diagnosis and/or receipt of intensive care-level pulmonary vasodilator therapy. Multivariable logistic regression identified independent associations with mortality. Measurements and Main Results: We analyzed 2,602 admissions; mortality was 10% versus 3.9% for all other medical admissions. Covariates most strongly associated with mortality included invasive ventilation (adjusted odds ratio, 44.8; 95% confidence interval, 6.2-323), noninvasive ventilation (19.7; 2.8-140), cardiopulmonary resuscitation (8.9; 5.6-14.1), and vasoactive infusions (4.8; 2.6-8.8). Patients receiving both invasive ventilation and vasoactive infusions on admission Days 1 and 2 had an observed mortality rate of 29.2% and 28.6%, respectively, compared with <5% for those not receiving either. Vasoactive infusions emerged as the dominant early risk factor for mortality, increasing the absolute risk of mortality on average by 6.4% when present on admission Day 2. Conclusions: Patients with PH admitted to pediatric cardiac critical care units have high mortality rates. Those receiving invasive ventilation and vasoactive infusions on Day 1 or Day 2 had an observed mortality rate that was more than fivefold greater than that of those who did not. These data highlight the illness severity of patients with PH in this setting and could help inform conversations with families regarding the prognosis.

Update on pediatric pulmonary arterial hypertension

PURPOSE OF REVIEW

Pulmonary arterial hypertension (PAH) causes high morbidity and mortality in children. In this review, we discuss advances in diagnosis and treatment of this disorder.

RECENT FINDINGS

Proceedings published from the 2018 World Symposium updated the definition of pulmonary hypertension to include all adults and children with mean pulmonary artery pressure more than 20 mmHg. Targeted PAH therapy is increasingly used off-label, but in 2017, bosentan became the first Food and Drug Administration-targeted PAH therapy approved for use in children.

SUMMARY

In recent years, advanced imaging and clinical monitoring have allowed improved risk stratification of pulmonary hypertension patients. New therapies, approved in adults and used off-label in pediatric patients, have led to improved outcomes for affected children.

Intensive care management of right ventricular failure and pulmonary hypertension crises

Pulmonary hypertension (PH), an often unrelenting disease that carries with it significant morbidity and mortality, affects not only the pulmonary vasculature but, in turn, the right ventricle as well. The survival of patients with PH is closely related to the right ventricular function. Therefore, having an understanding of how to manage right ventricular failure (RVF) and acute pulmonary hypertensive crises is imperative for clinicians who encounter these patients. This review addresses the management of these patients in detail, addressing: (a) the pathophysiology of RVF, (b) intensive care monitoring of these patients in the intensive care unit, (c) imaging of the right ventricle, (d) intubation and mechanical ventilation, (e) inotrope and vasopressor selection, (f) pulmonary vasodilator use, (g) interventional and surgical procedures for the acutely failing right ventricle, and (h) mechanical support for RVF.

Pediatric Pulmonary Arterial Hypertension

Pulmonary hypertension (PH), the syndrome of increased pressure in the pulmonary arteries, is associated with significant morbidity and mortality for affected children and is associated with a variety of potential underlying causes. Several pulmonary arterial hypertension-targeted therapies have become available to reduce pulmonary artery pressure and improve outcome, but there is still no cure for most patients. This review provides a description of select causes of PH encountered in pediatrics and an update on the most recent data pertaining to evaluation and management of children with PH. Available evidence for specific classes of PH-targeted therapies in pediatrics is discussed.

Lung disease and pulmonary hypertension in the premature infant

The premature infant is born into the world unprepared to naturally thrive in a foreign environment. Lung development entails immense growth, structural remodeling and differentiation of specialized cells during the normal term perinatal and postnatal periods. Thus, the premature infant presents with a lung deficient for appropriate respiration. Disruption of lung development seen in bronchopulmonary dysplasia (BPD) and chronic lung disease (CLD) results in not only impaired airway growth but also a deficiency in the accompanying vasculature including the capillary system required for gas exchange. Deficient vascular area can lead to elevated pulmonary vascular resistance and the development of pulmonary hypertension (PH). Unlike PH seen in children and adults with pulmonary arterial hypertension (PAH), treatment with conventional pulmonary vasodilators can be limited in developmental lung disease-associated PH because there are fewer blood vessels to dilate. In this brief review, we highlight some of the knowledge on PH in the premature infant presented at the Proceedings of the 22^nd Annual Update on Pediatric and Congenital Cardiovascular Disease.

Targeting Bronchopulmonary Dysplasia-Associated Pulmonary Hypertension (BPD-PH): Potential Role of the FGF Signaling Pathway in the Development of the Pulmonary Vascular System

More than 50 years after the first description of Bronchopulmonary dysplasia (BPD) by Northway, this chronic lung disease affecting many preterm infants is still poorly understood. Additonally, approximately 40% of preterm infants suffering from severe BPD also suffer from Bronchopulmonary dysplasia-associated pulmonary hypertension (BPD-PH), leading to a significant increase in total morbidity and mortality. Until today, there is no curative therapy for both BPD and BPD-PH available. It has become increasingly evident that growth factors are playing a central role in normal and pathologic development of the pulmonary vasculature. Thus, this review aims to summarize the recent evidence in our understanding of BPD-PH from a basic scientific point of view, focusing on the potential role of Fibroblast Growth Factor (FGF)/FGF10 signaling pathway contributing to disease development, progression and resolution.

Extracorporeal Membrane Oxygenation in Pediatric Pulmonary Hypertension

OBJECTIVE

To describe the epidemiology, critical care interventions, and mortality of children with pulmonary hypertension receiving extracorporeal membrane oxygenation.

DESIGN

Retrospective analysis of prospectively collected multicenter data.

SETTING

Data entered into the Extracorporeal Life Support Organization database between January 2007 and November 2018.

PATIENTS

Pediatric patients between 28 days and 18 years old with a diagnosis of pulmonary hypertension.

MEASUREMENTS AND MAIN RESULTS

Six hundred thirty-four extracorporeal membrane oxygenation runs were identified (605 patients). Extracorporeal membrane oxygenation support type was pulmonary (43.1%), cardiac (40.2%), and extracorporeal cardiopulmonary resuscitation (16.7%). The majority of cannulations were venoarterial (80.4%), and 30% had a pre-extracorporeal membrane oxygenation cardiac arrest. Mortality in patients with pulmonary hypertension was 51.3% compared with 44.8% (p = 0.001) in those without pulmonary hypertension. In univariate analyses, significant predictors of mortality included age less than 6 months and greater than 5 years; pre-extracorporeal membrane oxygenation cardiac arrest; pre-extracorporeal membrane oxygenation blood gas with pH less than 7.12, PaCO2 greater than 75, PaO2 less than 35, and arterial oxygen saturation less than 60%; extracorporeal membrane oxygenation duration greater than 280 hours; extracorporeal cardiopulmonary resuscitation; and extracorporeal membrane oxygenation complications including cardiopulmonary resuscitation, inotropic support, myocardial stun, tamponade, pulmonary hemorrhage, intracranial hemorrhage, seizures, other hemorrhage, disseminated intravascular coagulation, renal replacement therapy, mechanical/circuit problem, and metabolic acidosis. A co-diagnosis of pneumonia was associated with significantly lower odds of mortality (odds ratio, 0.5; 95% CI, 0.3-0.8). Prediction models were developed using three sets of variables: 1) pre-extracorporeal membrane oxygenation (age, absence of pneumonia, and pH < 7.12; area under the curve, 0.62); 2) extracorporeal membrane oxygenation related (extracorporeal cardiopulmonary resuscitation, any neurologic complication, pulmonary hemorrhage, renal replacement therapy, and metabolic acidosis; area under the curve, 0.72); and 3) all variables combined (area under the curve, 0.75) (p < 0.001).

CONCLUSIONS

Children with pulmonary hypertension who require extracorporeal membrane oxygenation support have a significantly greater odds of mortality compared with those without pulmonary hypertension. Risk factors for mortality include age, absence of pneumonia, pre-extracorporeal membrane oxygenation acidosis, extracorporeal cardiopulmonary resuscitation, pulmonary hemorrhage, neurologic complications, renal replacement therapy, and acidosis while on extracorporeal membrane oxygenation. Identification of those pulmonary hypertension patients requiring extracorporeal membrane oxygenation who are at even higher risk for mortality may inform clinical decision-making and improve prognostic awareness.

Translation of the Frailty Paradigm from Older Adults to Children with Cardiac Disease

Children and adolescents with cardiac disease (CCD) have significant morbidity and lower quality of life. However, there are no broadly applicable tools similar to the frailty score as described in the elderly, to define functional phenotype in terms of physical capability and psychosocial wellbeing in CCD. The purpose of this study is to investigate the domains of the frailty in CCD. We prospectively recruited CCD (8-17.5 years old, 70% single ventricle, 27% heart failure, 12% pulmonary hypertension; NYHA classes I, II and III) and age and gender matched healthy controls (total n = 56; CCD n = 34, controls n = 22; age 12.6 ± 2.6 years; 39.3% female). We measured the five domains of frailty: slowness, weakness, exhaustion, body composition and physical activity using developmentally appropriate methods. Age and gender-based population norms were used to obtain Z scores and percentiles for each measurement. Two-tailed t-tests were used to compare the two groups. The CCD group performed significantly worse in all five domains of frailty compared to healthy controls. Slowness: 6-min walk test with Z score -3.9 ± 1.3 vs -1.4 ± 1.3, p < 0.001; weakness: handgrip strength percentile 18.9 ± 20.9 vs 57.9 ± 26.0, p < 0.001; exhaustion: multidimensional fatigue scale percentile 63.7 ± 13.5 vs 83.3 ± 14.4, p < 0.001; body composition: height percentile 43.4 ± 29.5 vs 71.4 ± 25.2, p < 0.001, weight percentile 46.0 ± 36.0 vs 70.9 ± 24.3, p = 0.006, BMI percentile 48.4 ± 35.5 vs 66.9 ± 24.2, p = 0.04, triceps skinfold thickness 41.0 ± 24.0 vs 54.4 ± 22.1, p = 0.04; physical activity: pediatric activity questionnaire score 2 ± 0.6 vs 2.7 ± 0.6, p < 0.001. The domains of frailty can be quantified in children using developmentally appropriate methods. CCD differ significantly from controls in all five domains, supporting the concept of quantifying the domains of frailty. Larger longitudinal studies are needed to study frailty in CCD and examine if it predicts adverse health outcomes.Clinical Trial Registration: The ClinicalTrials.gov identification number is NCT02999438. https://clinicaltrials.gov/ct2/show/NCT02999438.

Treatment of pediatric pulmonary arterial hypertension: A focus on the NO-sGC-cGMP pathway

OBJECTIVE

While pulmonary arterial hypertension (PAH) is rare in infants and children, it results in substantial morbidity and mortality. In recent years, prognosis has improved, coinciding with the introduction of new PAH-targeted therapies, although much of their use in children is off-label. Evidence to guide the treatment of children with PAH is less extensive than for adults. The goal of this review is to discuss the treatment recommendations for children with PAH, as well as the evidence supporting the use of prostanoids, endothelin receptor antagonists (ERAs), and phosphodiesterase type 5 inhibitors (PDE5i) in this setting.

DATA SOURCES

Nonsystematic PubMed literature search and authors' expertise.

STUDY SELECTION

Articles were selected concentrating on the nitric oxide (NO)-soluble guanylate cyclase (sGC)-cyclic guanosine monophosphate (cGMP) pathway in PAH. The methodology of an ongoing study evaluating the sGC stimulator riociguat in children with PAH is also described.

RESULTS

Despite recent medical advances, improved therapeutic strategies for pediatric PAH are needed. The efficacy and tolerability of riociguat in adults with PAH have been well trialed.

CONCLUSION

The pooling of data across trials, supplemented by registry data, will help to confirm the safety and tolerability of prostanoids, ERAs, and PDE5i in children. Ongoing studies will clarify the place of sGC stimulators in the treatment strategy for pediatric PAH.

Retrospective observational analysis of hospital discharge database to characterize primary pulmonary hypertension and its outcomes in Spain from 2004 to 2015

To examine trends in the incidence, characteristics and outcomes, and to identify factors associated with in-hospital mortality (IHM) of patients hospitalized for primary pulmonary hypertension (PPH) in Spain (2004-2015).We included all patients hospitalized with PPH and included in the Spanish National Hospital Discharge Database.We analyzed 46,883 discharges of patients (7.14% with PPH as their primary diagnosis). Incidence rates decreased from 6.15 cases per 100,000 inhabitants in 2004-06 to 3.40 in 2013-15 (P < .001). Mean age rose from 66.43 ± 21.28 to 69.73 ± 21.12 years (P < .001) and the proportion of females increased over the study period (58.44% vs 60.71%; P < .001). Comorbidity using the Charlson Comorbidity Index (CCI) also increased with 16.07% having CCI ≥3 in 2004-06 vs 21.795 in 2013-15. Median length of hospital stay (LOHS) was 1 day longer in period 2004-06, than in 2013-15 (9 vs 8 days; P < .001). The proportion of patients who were considered a readmission and the mean costs increased from 15.7% and 3712.46&OV0556; in the first period to 17.14% and 4040.28&OV0556; in 2013-15 (P < .001). IHM increased from 8.2% in 2004-06 to 9.93% in 2013-15 (P < .001). The predictors' of IHM among PPH patients included comorbidity and use of mechanical ventilation. Primary diagnosis of PPH did not predict higher IHM (OR 1.07; 95%CI 09-1.26).Our data indicates that the incidence of hospitalizations decreased in Spain between 2004 and 2015. Parallel, LOHS also decreased during this period. By contrast, comorbidity increased over time in PPH patients, as well as readmission rates, costs and IHM.

Aicardi goutières syndrome is associated with pulmonary hypertension

While pulmonary hypertension (PH) is a potentially life threatening complication of many inflammatory conditions, an association between Aicardi Goutières syndrome (AGS), a rare genetic cause of interferon (IFN) overproduction, and the development of PH has not been characterized to date. We analyzed the cardiac function of individuals with AGS enrolled in the Myelin Disorders Bioregistry Project using retrospective chart review (n = 61). Additional prospective echocardiograms were obtained when possible (n = 22). An IFN signature score, a marker of systemic inflammation, was calculated through the measurement of mRNA transcripts of type I IFN-inducible genes (interferon signaling genes or ISG). Pathologic analysis was performed as available from autopsy samples. Within our cohort, four individuals were identified to be affected by PH: three with pathogenic gain-of-function mutations in the IFIH1 gene and one with heterozygous TREX1 mutations. All studied individuals with AGS were noted to have elevated IFN signature scores (Mann-Whitney p < .001), with the highest levels in individuals with IFIH1 mutations (Mann-Whitney p < .0001). We present clinical and histologic evidence of PH in a series of four individuals with AGS, a rare interferonopathy. Importantly, IFIH1 and TREX1 may represent a novel cause of PH. Furthermore, these findings underscore the importance of screening all individuals with AGS for PH.

Intensive Care Mortality Prognostic Model for Pediatric Pulmonary Hypertension

OBJECTIVES

The disease burden and mortality of children with pulmonary hypertension are significantly higher than for the general PICU population. We aimed to develop a risk-adjustment tool predicting PICU mortality for pediatric pulmonary hypertension patients: the Pediatric Index of Pulmonary Hypertension Intensive Care Mortality score.

DESIGN

Retrospective analysis of prospectively collected multicenter pediatric critical care data.

SETTING

One-hundred forty-three centers submitting data to Virtual Pediatric Systems database between January 1, 2009, and December 31, 2015.

PATIENTS

Patients 21 years old or younger with a diagnosis of pulmonary hypertension.

INTERVENTIONS

Twenty-one demographic, diagnostic, and physiologic variables obtained within 12 hours of PICU admission were assessed for inclusion. Multivariable logistic regression with stepwise selection was performed to develop the final model. Receiver operating characteristic curves were used to compare the Pediatric Index of Pulmonary Hypertension Intensive Care Mortality score with Pediatric Risk of Mortality 3 and Pediatric Index of Mortality 2 scores.

MEASUREMENTS AND MAIN RESULTS

Fourteen-thousand two-hundred sixty-eight admissions with a diagnosis of pulmonary hypertension were included. Primary outcome was PICU mortality. Fourteen variables were selected for the final model: age, bradycardia, systolic hypotension, tachypnea, pH, FIO2, hemoglobin, blood urea nitrogen, creatinine, mechanical ventilation, nonelective admission, previous PICU admission, PICU admission due to nonsurgical cardiovascular disease, and cardiac arrest immediately prior to admission. The receiver operating characteristic curve for the Pediatric Index of Pulmonary Hypertension Intensive Care Mortality model (area under the curve = 0.77) performed significantly better than the receiver operating characteristic curves for Pediatric Risk of Mortality 3 (area under the curve = 0.71; p < 0.001) and Pediatric Index of Mortality 2 (area under the curve = 0.69; p < 0.001), respectively.

CONCLUSIONS

The Pediatric Index of Pulmonary Hypertension Intensive Care Mortality score is a parsimonious model that performs better than Pediatric Risk of Mortality 3 and Pediatric Index of Mortality 2 for mortality in a multicenter cohort of pediatric pulmonary hypertension patients admitted to PICUs. Application of the Pediatric Index of Pulmonary Hypertension Intensive Care Mortality model to pulmonary hypertension patients in the PICU might facilitate earlier identification of patients at high risk for mortality and improve the ability to prognosticate for patients and families.

National trends and outcomes of hospitalizations for pulmonary hypertension in Spain (2001-2014)

OBJECTIVE

To assess changes in incidence, diagnostic procedures, comorbidity profiles, length of hospital stay (LOHS), costs, and in-hospital mortality (IHM) for patients hospitalized with pulmonary hypertension (PH).

METHODS

We included patients hospitalized with PH in Spain from 2001 to 2014. The data were collected from the National Hospital Discharge Database.

RESULTS

We included 644,436 discharges (43.31% males and 56.09% females) admitted for primary PH (8.34%) or secondary PH (91.66%). The crude incidence rate increased from 58.67 to 148.32 hospitalizations per 100,000 inhabitants between 2001 and 2002 and 2013-2014 (p < 0.001). The percentage of patients with a Charlson comorbidity index ≥2 was 27.87% in 2001-2002, increasing to 47.02% in 2013-2014 (p < 0.001). IHM was 8.77%, with a reduction in the value yielded by the multivariable analysis between 2009 and 2010 and 2013-2014. Median LOHS was 9 ± 9 days in 2001-2002, which decreased to 7 ± 8 days in 2013-2014 (p < 0.001). The mean cost per patient increased from €3352.4 ± €1495 in the period 2001-2002 to €4198.94 ± €1287.96 in 2013-2014 (p < 0.001).

CONCLUSIONS

Despite the increase over time in hospital admissions for PH, associated comorbidity, and costs, LOHS and IHM decreased, suggesting that the management of PH-related hospitalizations improved in Spain during the study period.

Breathing (and Coding?) a Bit Easier: Changes to International Classification of Disease Coding for Pulmonary Hypertension

The International Classification of Disease (ICD) coding system is broadly used by health-care providers, hospitals, health-care payers, and governments to track health trends and statistics at the global, national, and local levels and to provide a reimbursement framework for medical care based on diagnosis and severity of illness. The current iteration of the ICD system, the ICD, Tenth Revision (ICD-10), was implemented in 2015. Although many changes to the prior ICD, Ninth Revision system were included in the ICD-10 system, the newer revision failed to adequately reflect advances in the clinical classification of certain diseases such as pulmonary hypertension (PH). Recently, a proposal to modify the ICD-10 codes for PH was considered and ultimately adopted for inclusion as an update to the ICD-10 coding system. Although these revisions better reflect the current clinical classification of PH, in the future, further changes should be considered to improve the accuracy and ease of coding for all forms of PH.

Hospital Readmissions in Children with Pulmonary Hypertension: A Multi-Institutional Analysis

OBJECTIVE

To assess the rate of and risk factors for 30-day hospital readmission in children with pulmonary hypertension.

STUDY DESIGN

The Pediatric Health Information System database was analyzed for patients ≤18 years old with pulmonary hypertension (International Classification of Diseases, Ninth Revision, diagnosis codes of 416.0, 416.1, 416.8, or 416.9) admitted from 2005 through 2014. A generalized hierarchical regression model was used to determine significant ORs and 95% CIs associated with 30-day readmission.

RESULTS

A total of 13580 patients met inclusion criteria (median age 1.7 years [IQR 0.3-8.7], 45.3% with congenital heart disease). Admissions increased 4-fold throughout the study period. Associated hospital charges increased from $119 million in 2004 to $929 million in 2014. During initial admission, 57.4% of patients required admission to the intensive care unit, and 48.2% required mechanical ventilation. The 30-day readmission rate was 26.3%. Mortality during readmission was 4.2%. Factors increasing odds of readmission included a lower hospital volume of pulmonary hypertension admissions (1.41 [1.23-1.57], P < .001) and having public insurance (1.26 [1.16-1.38], P < .001). Decreased odds of readmission were associated with older age and the presence of congenital heart disease (0.86 [0.79-0.93], P < .001).

CONCLUSIONS

The pediatric pulmonary hypertension population carries significant morbidity, as reflected by a high use of intensive care unit resources and a high 30-day readmission rate. Younger patients and those with public insurance represent particularly at-risk groups.

Diagnosis, Evaluation and Treatment of Pulmonary Arterial Hypertension in Children

Pulmonary Hypertension (PH), the syndrome of elevated pressure in the pulmonary arteries, is associated with significant morbidity and mortality for affected children. PH is associated with a wide variety of potential underlying causes, including cardiac, pulmonary, hematologic and rheumatologic abnormalities. Regardless of the cause, for many patients the natural history of PH involves progressive elevation in pulmonary arterial resistance and pressure, right ventricular dysfunction, and eventually heart failure. In recent years, a number of pulmonary arterial hypertension (PAH)-targeted therapies have become available to reduce pulmonary artery pressure and improve outcome. A growing body of evidence in both the adult and pediatric literature demonstrates enhanced quality of life, functional status, and survival among treated patients. This review provides a description of select etiologies of PH seen in pediatrics and an update on the most recent data pertaining to evaluation and management of children with PH/PAH. The available evidence for specific classes of PAH-targeted therapies in pediatrics is additionally discussed.

Multicenter mortality and morbidity associated with pulmonary hypertension in the pediatric intensive care unit

Despite advances in the diagnosis and management of pediatric pulmonary hypertension (PH), children with PH represent a growing inpatient population with significant morbidity and mortality. To date, no studies have described the clinical characteristics of children with PH in the pediatric intensive care unit (PICU). A retrospective multicenter cohort study of 153 centers in the Virtual PICU Systems database who submitted data between 1 January 2009 and 31 December 2015 was performed. A total of 14,880/670,098 admissions (2.2%) with a diagnosis of PH were identified. Of these, 2190 (14.7%) had primary PH and 12,690 (85.3%) had secondary PH. Mortality for PH admissions was 6.8% compared to 2.3% in those admitted without PH (odds ratio = 3.1; 95% confidence interval = 2.9–3.4). Compared to patients admitted to the PICU without PH, those with PH were younger, had longer length of stay, higher illness severity scores, were more likely to receive invasive mechanical ventilation, cardiopulmonary resuscitation, extracorporeal membrane oxygenation, and more likely to have co-diagnoses of sepsis, heart failure, and respiratory failure. In a multivariate model, factors significantly associated with mortality for children with PH included age < 6 months or > 16 years, invasive mechanical ventilation, and co-diagnoses of heart failure, sepsis, hemoptysis, disseminated intravascular coagulation, stroke, and multi-organ dysfunction syndrome. Despite therapeutic advances, the disease burden and mortality of children with PH remains significant. Further investigation of the risk factors associated with clinical deterioration and mortality in this population could improve the ability to prognosticate and inform clinical decision-making.

Adverse Outcomes in Neonates and Children with Pulmonary Artery Hypertension Supported with ECMO

Extracorporeal membrane oxygenation (ECMO) has been increasingly used to rescue neonates and children with cardiac or respiratory failure, and critical illnesses including pulmonary artery hypertension (PAH) unresponsive to conventional therapies. This study assesses mortality and outcomes in neonates and children with PAH supported with ECMO. Neonates and children from the 2012 Health Care Cost and Use Project Kids' Database were identified using ICD-9 codes. Children with congenital heart disease were excluded. Univariate logistic regression was applied to assess the relationship between ECMO and outcomes using matched cohorts for age, elective admission, and Elixhauser comorbidity score. We identified 9,355 neonates and children with PAH (0.15%). The incidence of ECMO was 1.4% (132/9,355). After propensity-matched analysis, 130 neonates and children were included in each group. The incidence of mortality was 39% in the group supported with ECMO and 8% in the control group (odds ratio [OR]: 6.98, 95% confidence interval [CI]: 3.43-14.21, p < 0.001). Neonates and children on ECMO had higher odds for acute kidney injury (OR: 2.41, 95% CI: 1.30-4.47, p = 0.005), neurologic complications (OR: 7.11, 95% CI: 1.57-32.18, p = 0.011), sepsis (OR: 2.69, 95% CI: 1.46-4.96, p = 0.002), and thrombotic complications (OR: 2.90, 95% CI: 1.10-7.67, p = 0.032). Neonates and children with PAH supported with ECMO have higher mortality rate and complications compared with matched controls with PAH.

Characteristics of pediatric pulmonary hypertension trials registered on ClinicalTrials.gov

The investigation of pediatric pulmonary hypertension (PH) drugs has been identified as a high priority by the United States National Institutes of Health (NIH). Studying pediatric PH is challenging due to the rare and heterogeneous nature of the disease. We sought to define the pediatric PH clinical trials landscape, to evaluate areas of trial success or failure, and to identify potential obstacles to the study of pediatric PH drugs. Interventional pediatric (ages 0–17 years) PH trials registered on ClinicalTrials.gov from June 2005 through December 2014 were analyzed. There were 45 pediatric PH trials registered during the study period. Median (IQR) projected trial enrollment was 40 (24–63), with seven trials (16%) targeting > 100 participants. Industry was the most common trial sponsor (n = 23, 50%), with only two (4.4%) NIH-sponsored trials. Phosphodiesterase inhibitors were the most frequently studied drug (n = 18, 39%). Single group study designs were used in 44% (n = 20) with an active comparator (parallel, factorial, or cross-over designs) in 25 trials, including 22 with randomization and ten that were double-blinded. Study outcomes varied markedly with inconsistent use of known surrogate and composite endpoints. One-third of trials (n = 15, 33%) were terminated, predominantly due to poor participant enrollment. Of the 17 completed trials, 11 had published results and only three efficacy trials met their primary endpoint. There are unique challenges to drug development in pediatric PH, including enrolling patients, identifying appropriate study endpoints, and conducting randomized, controlled, double-blind trials where the likelihood of meeting the study endpoint is optimized.

Pulmonary arterial hypertension in the USA: an epidemiological study in a large insured pediatric population

Pulmonary arterial hypertension (PAH) is rare in children and few data are available in a pediatric general population. This study aims to calculate the annual incidence and prevalence of PAH and to describe these children in a large US population of patients aged under 18 years. Using the US MarketScan claims database we identified 695 children with PAH in 2010-2013. We calculated annual incidence rates and prevalence overall, by age and PAH type (idiopathic and non-idiopathic) using Byar's method. We also described characteristics, co-morbidities, treatment patterns, and diagnostic procedures for these children. In 2010-2013, the annual incidence rates of PAH per 1,000,000 children-years was in the range of 4.8-8.1; 0.5-0.9 for idiopathic PAH and 4.3-7.3 for non-idiopathic PAH. The annual prevalence of PAH was in the range of 25.7-32.6 per 1,000,000 children; 4.4-6.0 for idiopathic PAH and 21.3-27.0 for non-idiopathic PAH. Incidence rates and prevalence were highest in children under age 2 years. Around 36% of affected children were born prematurely. Most (75%) had some type of congenital heart defect and 13% had Down's syndrome. Most patients received PAH monotherapy (83%), while 13% received dual therapy. Phosphodiesterase type 5 inhibitors were the most commonly used treatments. Around 92% had at least one echocardiogram and 37% a right heart catheterization. PAH is very rare in children especially in the absence of etiological factors such as congenital heart defects. A large proportion of diagnoses in children seem to be based on echocardiography rather than right heart catheterization.

Perioperative considerations and complications in pediatric parathyroidectomy

OBJECTIVES/HYPOTHESIS

To evaluate perioperative considerations and post-operative complications associated with parathyroidectomy in the pediatric population.

METHODS

The Kids' Inpatient Database 21 (KID) was searched for patients who underwent parathyroidectomy in 2009 and 2012. Patient demographics, hospital stay, associated charges, and post-operative adverse sequelae were evaluated in all patients and included patient comorbidity and additional procedure requirement analysis.

RESULTS

There were 182 patients extrapolating to 262 parathyroidectomies over the two years analyzed. Although a minority of patients were male (45.4%), these patients had greater rates of complications, length of stay, and hospital charges. Importantly, minorities and younger patients (≤15y) also had more complicated post-operative courses. The lengths of stay for patients experiencing post-operative altered mental status (18.7d), post-operative infection (15.5d), respiratory complications (19d), and cardiac complications (13d) were significantly increased compared to individuals without major complications (3.4d) (p < 0.001). Patients with pre-existing chronic kidney disease, dialysis-dependence, and bone sequelae (most commonly from hungry bone syndrome) also had significantly lengthier stays and greater associated costs.

CONCLUSION

Findings from this analysis can be included in a comprehensive pre-operative informed consent process between physicians and patients discussing perioperative considerations and potential complications of parathyroidectomy. Males, younger children, and patients with preexisting renal conditions experienced lengthier and more complicated hospital stays, suggesting the need for closer monitoring of these cohorts.

Executive summary. Expert consensus statement on the diagnosis and treatment of paediatric pulmonary hypertension. The European Paediatric Pulmonary Vascular Disease Network, endorsed by ISHLT and DGPK

: The European Paediatric Pulmonary Vascular Disease (PVD) Network is a registered, non-profit organisation that strives to define and develop effective, innovative diagnostic methods and treatment options in all forms of paediatric pulmonary hypertensive vascular disease, including specific forms such as pulmonary arterial hypertension (PAH)-congenital heart disease, pulmonary hypertension (PH) associated with bronchopulmonary dysplasia, persistent PH of the newborn, and related cardiac dysfunction.

METHODS

The writing group members conducted searches of the PubMed/MEDLINE bibliographic database (1990-2015) and held five face-to-face meetings with votings. Clinical trials, guidelines, and reviews limited to paediatric data were searched using the terms 'pulmonary hypertensioń' and 5-10 other keywords, as outlined in the other nine articles of this special issue. Class of recommendation (COR) and level of evidence (LOE) were assigned based on European Society of Cardiology/American Heart Association definitions and on paediatric data only, or on adult studies that included >10% children.

RESULTS

A total of 9 original consensus articles with graded recommendations (COR/LOE) were developed, and are summarised here. The topics included diagnosis/monitoring, genetics/biomarker, cardiac catheterisation, echocardiography, cardiac magnetic resonance/chest CT, associated forms of PH, intensive care unit/ventricular assist device/lung transplantation, and treatment of paediatric PAH.

CONCLUSIONS

The multipaper expert consensus statement of the European Paediatric PVD Network provides a specific, comprehensive, detailed but practical framework for the optimal clinical care of children with PH.

Pulmonary Hypertension in Children

The prevalence of PH is increasing in the pediatric population, because of improved recognition and increased survival of patients, and remains a significant cause of morbidity and mortality. Recent studies have improved the understanding of pediatric PH, but management remains challenging because of a lack of evidence-based clinical trials. The growing contribution of developmental lung disease requires dedicated research to explore the use of existing therapies as well as the creation of novel therapies. Adequate study of pediatric PH will require multicenter collaboration due to the small numbers of patients, multifactorial disease causes, and practice variability.

Persistent Challenges in Pediatric Pulmonary Hypertension

Pulmonary hypertension and related pulmonary vascular diseases cause significant morbidities and high mortality and present many unique challenges toward improving outcomes in neonates, infants, and children. Differences between pediatric and adult disease are reflected in controversies regarding etiologies, classification, epidemiology, diagnostic evaluations, and therapeutic interventions. This brief review highlights several key topics reflecting recent advances in the field and identifies persistent gaps in our understanding of clinical pediatric pulmonary hypertension.