Pulmonary Arterial Capacitance Index Is a Strong Predictor for Adverse Outcome in Children with Idiopathic and Heritable Pulmonary Arterial Hypertension.

OBJECTIVES: To evaluate the clinical utility of pulmonary artery capacitance index (PACi) in the assessment of disease severity and prognostic value in children with idiopathic and heritable pulmonary arterial hypertension (PAH). STUDY DESIGN: PACi is defined as the ratio of stroke volume index over pulmonary pulse pressure. A retrospective study was performed to compare PACi, brain natriuretic peptide (BNP), 6-minute walk distance, New York Heart association (NYHA) functional class, and adverse outcomes (hospitalization due to heart failure, lung transplantation, and cardiac mortality) in 72 Japanese children (10 ± 3.6 years) with idiopathic and heritable PAH. RESULTS: PACi had significant correlations with pulmonary vascular resistance index (r =-0.73, P < .0001), BNP levels (r = -0.40, P = .0008), and 6-minute walk distance (r = 0.57, P < .05). Statistically significant differences in PACi were observed between NYHA functional class II vs combined III and IV (median; 1.1 vs 0.6 mL/mm Hg/m2, respectively, P < .05). There were 25 of 72 (35%) children who had an adverse event including initiation of hospitalization due to heart failure, lung transplantation, and death. Cumulative event-free survival rate was significantly lower when PACi was <0.85 mL/mm Hg/m2 (log-rank test, P < .0001). CONCLUSIONS: PACi correlated with BNP and NYHA functional class and may serve as a strong prognostic marker in children with idiopathic and heritable PAH.

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.

Current challenges in pediatric pulmonary hypertension.

Pulmonary arterial hypertension (PAH) in the pediatric population is associated with a variety of underlying diseases and causes, significantly morbidity and mortality. In the majority of patients, PAH in children is idiopathic or associated with congenital heart disease (CHD), with pulmonary hypertension (PH) associated with connective tissue disease, a rare cause in children. Classification of pediatric PH has generally followed the WHO classification, but recognition of the importance of fetal origins of PH and developmental abnormalities have led to the formation of a new pediatric-specific classification. Incidence data from the Netherlands has revealed an annual incidence and point prevalence of 0.7 and 4.4 for idiopathic PAH and 2.2 and 15.6 for associated pulmonary arterial hypertension-CHD cases per million children. Although the treatment with new selective pulmonary vasodilators offers hemodynamic and functional improvement in pediatric populations, the treatments in children largely depend on results from evidence-based adult studies and experience of clinicians treating children. A recent randomized clinical trial of sildenafil and its long-term extension has led to disparate recommendations in the United States and Europe.

Correlation of N-terminal fragment of B-type natriuretic peptide levels with clinical, laboratory, and echocardiographic abnormalities in children with sickle cell disease.

OBJECTIVE: To determine whether the N-terminal fragment of B-type natriuretic peptide (NTproBNP) was a biomarker of clinical, laboratory, and echocardiographic abnormalities in children with homozygous sickle cell disease. STUDY DESIGN: We conducted a single-center retrospective study that consisted of analysis of data from November 2007 to December 2010. We correlated serum NTproBNP with clinical and laboratory findings, echocardiographic data, and New York Heart Association (NYHA) functional class. RESULTS: NTproBNP levels from 42 children (median age, 9 years; 52% female) had significant correlations with hemoglobin (r = -0.63, P < .05), and echocardiographic measurements including tricuspid regurgitant velocity (r = 0.46, P < .05), lateral E' (r = -0.52, P < .05), and lateral E/E' ratio (r = 0.60, P < .05), suggesting diastolic dysfunction. In addition, NTproBNP levels increased from NYHA functional class I to class III and had a significant linear correlation with the NYHA functional class (r = 0.69, P < .05). CONCLUSIONS: NTproBNP correlated with low hemoglobin and tissue Doppler data as indicators of diastolic dysfunction. Elevated NTproBNP may be a prognostic biomarker for the presence of diastolic dysfunction related to anemia in children with sickle cell disease.

Initial experience with tadalafil in pediatric pulmonary arterial hypertension.

This study aimed to investigate the safety, tolerability, and effects of tadalafil on children with pulmonary arterial hypertension (PAH) after transition from sildenafil or after tadalafil received as initial therapy. A total of 33 pediatric patients with PAH were retrospectively evaluated. Of the 33 patients, 29 were switched from sildenafil to tadalafil. The main reason for the change from sildenafil was once-daily dosing. The average dose of sildenafil was 3.4 ± 1.1 mg/kg/day, and that of tadalafil was 1.0 ± 0.4 mg/kg/day. For 14 of the 29 patients undergoing repeat catheterization, statistically significant improvements were observed after transition from sildenafil to tadalafil in terms of mean pulmonary arterial pressure (53.2 ± 18.3 vs. 47.4 ± 13.7 mmHg; p < 0.05) and pulmonary vascular resistance index (12.2 ± 7.0 vs 10.6 ± 7.2 Units/m(2); p < 0.05). Clinical improvement was noted for four patients treated with tadalafil as initial therapy. The side effect profiles were similar for the patients who had transitioned from sildenafil to tadalafil including headache, nausea, myalgia, nasal congestion, flushing, and allergic reaction. Two patients discontinued tadalafil due to migraine or allergic reaction. One patient receiving sildenafil had no breakthrough syncope after transition to tadalafil. Tadalafil can be safely used for pediatric patients with PAH and may prevent disease progression.

Clinical manifestations and long-term follow-up in pediatric patients living at altitude with isolated pulmonary artery of ductal origin.

This study's aim was to define the clinical manifestations and long-term outcome of pediatric patients living at altitude with isolated pulmonary artery (PA) of ductal origin (IPADO). This was a retrospective cohort study of 17 consecutive cases of IPADO at a single center. All patients lived at modest altitude (median 2050 m [range 1700 m to 3050 m]). Fifteen children (88%) were symptomatic at presentation. High-altitude pulmonary edema was present in 2 patients (12%) at diagnosis, and only 1 patient had episodes of hemoptysis during follow-up. Fourteen patients (82%) demonstrated evidence of pulmonary arterial hypertension (PAH). Among 14 patients with PAH, 11 patients had surgical interventions. PAH resolved in 5 of 11 patients (45%) undergoing surgical rehabilitation. One patient died during follow-up, and 7 patients are receiving oral vasodilator therapies due to residual PAH; 14 patients remained asymptomatic. Our study showed that early intervention in patients with IPADO at modest altitude can potentially rehabilitate the isolated PA and reverse PAH. Whether surgery is indicated for patients with this disorder in the absence of PAH is unknown.

Connective tissue disease presenting with signs and symptoms of pulmonary hypertension in children.

Our case series describes three children who were initially diagnosed as having severe pulmonary arterial hypertension (PAH) and subsequently found to be positive for specific autoantibodies suggestive of an underlying autoimmune process. The signs and symptoms of PAH are subtle and may be part of the initial presentation of childhood connective tissue disease (CTD). Evaluation for connective tissue disease in the newly diagnosed pulmonary hypertension (PH) patient is important because early diagnosis of PH as well as CTD is crucial in the successful management of these complex patients. Ongoing monitoring for CTD in patients with severe PAH is warranted.

Drug Treatment of Pulmonary Hypertension in Children.

Pulmonary arterial hypertension (PAH) is a rare disease in infants and children that is associated with significant morbidity and mortality. The disease is characterized by progressive pulmonary vascular functional and structural changes resulting in increased pulmonary vascular resistance and eventual right heart failure and death. In many pediatric patients, PAH is idiopathic or associated with congenital heart disease and rarely is associated with other conditions such as connective tissue or thromboembolic disease. PAH associated with developmental lung diseases such as bronchopulmonary dysplasia or congenital diaphragmatic hernia is increasingly more recognized in infants and children. Although treatment of the underlying disease and reversal of advanced structural changes have not yet been achieved with current therapy, quality of life and survival have improved significantly. Targeted pulmonary vasodilator therapies, including endothelin receptor antagonists, prostacyclin analogs, and phosphodiesterase type 5 inhibitors have resulted in hemodynamic and functional improvement in children. The management of pediatric PAH remains challenging as treatment decisions depend largely on results from evidence-based adult studies and the clinical experience of pediatric experts. This article reviews the current drug therapies and their use in the management of PAH in children.

A curious isolated cystic lesion of the membranous atrioventricular septum.

We present the case of an isolated cystic lesion of the atrioventricular component of the membranous septum of unclear aetiology, but responsible for cardiomegaly and benign disturbances of cardiac rhythm. As far as we are aware, this type of lesion has not previously been documented.

Predictive value of presuperior cavopulmonary anastomosis cardiac catheterization at increased altitude.

OBJECTIVE: Infants with single ventricle physiology typically undergo cardiac catheterization prior to superior cavopulmonary anastomosis (SCPA) to assess operative suitability. Predictors of poor outcome at sea level include elevated pulmonary artery pressure (mPAP), indexed pulmonary vascular resistance (PVRi), age <3 months, significant atrioventricular valve regurgitation, among others. Increased altitude has vasoconstrictive effects on the pulmonary vasculature, which may affect pre-SCPA hemodynamics and outcomes. The goal of this study was to determine the predictive value of pre-SCPA catheterization data with regard to reaching Fontan palliation at altitude. DESIGN: A retrospective review revealed 150 patients who underwent pre-SCPA catheterization over a 10-year period. Subjects were grouped by progression to Fontan vs aborted palliation, heart transplant or death. Statistics included t-tests, logistic regression and receiver operator characteristic (ROC) curve analysis. RESULTS: Independent predictors of failure to achieve Fontan operation at increased altitude include decreased ventricular function, increased mPAP, increased PVRi, and prolonged hospitalization, after adjusting for ventricular morphology and sex. CONCLUSIONS: Our data indicate that decreased ventricular function most strongly predicts failure to reach Fontan palliation. Additionally, mPAP and PVRi play an important role in determining outcomes at increased altitude. Prolonged hospitalization is likely a marker of increased medical complexity or more problematic physiology.

The Anesthetic Challenges of Lung Biopsy-Associated Intrathoracic Hemorrhage in a Child With Suprasystemic Pulmonary Hypertension.

Children with suspected pulmonary hypertension must undergo extensive and invasive evaluations to establish a definitive diagnosis. A previously healthy 4-year old girl, newly diagnosed with suprasystemic pulmonary hypertension required multiple lung biopsies. Each procedure was associated with significant bleeding. The challenging anesthetic management of lung biopsy in the presence of suprasystemic pulmonary hypertension is described.

Three-dimensional Echocardiography of Right Ventricular Function Correlates with Severity of Pediatric Pulmonary Hypertension.

BACKGROUND: Right ventricular function and biomarkers of B-type natriuretic peptide (BNP) and N-Terminal pro-BNP (NT pro-BNP) are used to determine the severity of right ventricular failure and outcomes from pulmonary hypertension. Real-time three-dimensional echocardiography (3DE) is a novel quantitative measure of the right ventricle and decreases the geometric assumptions from conventional two-dimensional echocardiography (2DE). We correlated right ventricular functional measures using 2DE and single-beat 3DE with biomarkers and hemodynamics to determine the severity of pediatric pulmonary hypertension. METHODS: We retrospectively evaluated 35 patients (mean age 12.67 ± 5.78 years) with established pulmonary hypertension who had echocardiograms and biomarkers on the same day. Ten out of 35 patients had hemodynamic evaluation within 3 days. 2DE evaluation included tricuspid annular plane systolic excursion (TAPSE), right ventricular myocardial performance index from tissue Doppler imaging (RV TDI MPI), and right ventricular fractional area change (FAC). Three-dimensional echocardiography evaluation included right ventricular ejection fraction (EF), end-systolic volume, and end-diastolic volume. The quality of the 3DE was graded as good, fair, or poor. Pearson correlation coefficients were utilized to evaluate between biomarkers and echocardiographic parameters and between hemodynamics and echocardiography. RESULTS: Three-dimensional echocardiography and FAC correlated significantly with BNP and NT pro-BNP. TAPSE and RV TDI MPI did not correlate significantly with biomarkers. 3D right ventricular EF correlated significantly with hemodynamics. Two-dimensional echocardiography did not correlate with hemodynamics. CONCLUSIONS: Single-beat 3DE is a noninvasive, feasible tool in the quantification of right ventricular function and maybe more accurate than conventional 2DE in evaluating severity of pulmonary hypertension.

Drug treatment of pulmonary hypertension in children.

Pulmonary arterial hypertension (PAH) is a rare disease in infants and children that is associated with significant morbidity and mortality. The disease is characterized by progressive pulmonary vascular functional and structural changes resulting in increased pulmonary vascular resistance and eventual right heart failure and death. In the majority of pediatric patients, PAH is idiopathic or associated with congenital heart disease and rarely is associated with other conditions such as connective tissue or thromboembolic disease. Although treatment of the underlying disease and reversal of advanced structural changes has not yet been achieved with current therapy, quality of life and survival have been improved significantly. Targeted pulmonary vasodilator therapies, including endothelin receptor antagonists, prostacyclin analogs, and phosphodiesterase type 5 inhibitors, have demonstrated hemodynamic and functional improvement in children. The management of pediatric PAH remains challenging, as treatment decisions continue to depend largely on results from evidence-based adult studies and the clinical experience of pediatric experts. This article reviews the current drug therapies and their use in the management of PAH in children.

Right ventricular to left ventricular diameter ratio at end-systole in evaluating outcomes in children with pulmonary hypertension.

BACKGROUND: Pulmonary hypertension (PH) increases right ventricular (RV) pressure, resulting in septal shift and RV dilation. Few echocardiographic measures have been used to evaluate severity and outcomes in children with PH. The aims of this study were to compare the RV to left ventricular (LV) diameter ratio at end-systole (RV/LV ratio) in normal controls and patients with PH, to correlate the RV/LV ratio with invasive hemodynamic measures, and to evaluate its association with outcomes in children with PH. METHODS: The RV/LV ratio was compared retrospectively between 80 matched normal controls and 84 PH patients without shunts. Of the patients with PH, 49 children underwent 94 echocardiographic studies and cardiac catheterizations within 48 hours (13 patients had simultaneous measurements). The RV/LV ratio was correlated against hemodynamic measures. Kaplan-Meier curves and a Cox proportional-hazards regression model were used to assess relationships between RV/LV ratio and time until an adverse clinical event (initiation of intravenous prostacyclin therapy, atrial septostomy, death, or transplantation). RESULTS: RV/LV ratios were lower in controls compared with patients with PH (mean, 0.51 [95% confidence interval, 0.48-0.54] vs 1.47 [95% confidence interval, 1.25-1.70], P < .01). The RV/LV ratio correlated significantly with mean pulmonary artery pressure, systolic pulmonary artery pressure, systolic pulmonary artery pressure as a percentage of systemic pressure, and pulmonary vascular resistance index (r = 0.65 [P < .01], r = 0.6 [P < .01], r = 0.49 [P < .01], and r = 0.43 [P < .01], respectively). Twenty-two patients with PH with RV/LV ratios > 1 had adverse events within a median of 1.1 years from their earliest echocardiographic studies. Increasing RV/LV ratio was associated with an increasing hazard for a clinical event (hazard ratio, 2.49; 95% confidence interval, 1.92-3.24). CONCLUSIONS: The RV/LV end-systolic diameter ratio can easily be obtained noninvasively in the clinical setting and can be used in the management of patients with PH. The RV/LV ratio incorporates both pathologic septal shift and RV dilation in children with PH and correlates with invasive measures of PH. An RV/LV ratio > 1 is associated with adverse clinical events.

Evaluation of circulating proteins and hemodynamics towards predicting mortality in children with pulmonary arterial hypertension.

BACKGROUND: Although many predictors have been evaluated, a set of strong independent prognostic mortality indicators has not been established in children with pediatric pulmonary arterial hypertension (PAH). The aim of this study was to identify a combination of clinical and molecular predictors of survival in PAH. METHODS: This single-center, retrospective cohort study was performed from children with PAH between 2001 and 2008 at Children's Hospital Colorado. Blood samples from 83 patients (median age of 8.3 years-old) were obtained. We retrospectively analyzed 46 variables, which included 27 circulating proteins, 7 demographic variables and 12 hemodynamic and echocardiographic variables for establishing the best predictors of mortality. A data mining approach was utilized to evaluate predictor variables and to uncover complex data structures while performing variable selection in high dimensional problems. RESULTS: Thirteen children (16%) died during follow-up (median; 3.1 years) and survival rates from time of sample collection at 1 year, 3 years and 5 years were 95%, 85% and 79%, respectively. A subset of potentially informative predictors were identified, the top four are listed here in order of importance: Tissue inhibitors of metalloproteinases-1 (TIMP-1), apolipoprotein-AI, RV/LV diastolic dimension ratio and age at diagnosis. In univariate analysis, TIMP-1 and apolipoprotein-AI had significant association with survival time (hazard ratio [95% confidence interval]: 1.25 [1.03, 1.51] and 0.70 [0.54-0.90], respectively). Patients grouped by TIMP-1 and apolipoprotein-AI values had significantly different survival risks (p<0.01). CONCLUSION: Important predictors of mortality were identified from a large number of circulating proteins and clinical markers in this cohort. If confirmed in other populations, measurement of a subset of these predictors could aid in management of pediatric PAH by identifying patients at risk for death. These findings also further support a role for the clinical utility of measuring circulating proteins.

B-type natriuretic peptide and amino-terminal pro-B-type natriuretic peptide in pediatric patients with pulmonary arterial hypertension.

OBJECTIVES: B-type natriuretic peptide (BNP) and the amino-terminal fragment (NTproBNP) correlate with clinical variables, but have not been simultaneously studied in a large number of pediatric patients with pulmonary arterial hypertension (PAH). The purpose of our investigation was to compare BNP and NTproBNP with clinical indicators of disease in a pediatric PAH population for which biomarkers are much needed. DESIGN: We retrospectively compared BNP and NTproBNP levels with exercise capacity, echocardiographic data, and hemodynamics in PAH patients under 21 years old. Two hundred sixty-three blood samples from 88 pediatric PAH patients were obtained, with BNP and NTproBNP drawn at the same time. RESULTS: There was a correlation between BNP and NTproBNP with mean pulmonary arterial pressure/mean systemic arterial pressure ratio (r= 0.40, P < .01; r= 0.45, P < .01; respectively), mean right atrial pressure (r= 0.48, P < .01; r= 0.48, P < .01), and tricuspid regurgitant velocity (r= 0.36, P < .01; r= 0.41, P < .01). BNP and NTproBNP are associated with 6-minute walk distance, mean pulmonary arterial pressure, mean pulmonary arterial pressure/mean systemic arterial pressure ratio, mean right atrial pressure, pulmonary vascular resistance index, and tricuspid regurgitant velocity when investigated longitudinally. On the average, a 1-unit increase in log BNP or NTproBNP was associated with 4.5 units × m(2) or 3.4 units × m(2) increase in pulmonary vascular resistance index, respectively. There was a strong correlation between log BNP and log NTproBNP measurements (r= 0.87, P < .01). CONCLUSION: In pediatric PAH, BNP and NTProBNP are strongly correlated and predict changes in clinical variables and hemodynamics. In a cross-sectional analysis, NTproBNP correlated with echocardiographic and exercise data better than BNP; NTproBNP showed less within patient variability over time; therefore, NTproBNP can add additional information toward predicting these clinical measurements.